.../drm/bridge/analogix/analogix_dp_core.c | 384 ++++++++++-------- .../drm/bridge/analogix/analogix_dp_core.h | 5 +- drivers/gpu/drm/exynos/exynos_dp.c | 48 +-- .../gpu/drm/rockchip/analogix_dp-rockchip.c | 49 +-- include/drm/bridge/analogix_dp.h | 7 +- 5 files changed, 248 insertions(+), 245 deletions(-)
PATCH 1 is a small format optimization for struct analogid_dp_device.
PATCH 2 is to perform mode setting in &drm_bridge_funcs.atomic_enable.
PATCH 3-6 are preparations for apply drm_bridge_connector helper.
PATCH 7 is to apply the drm_bridge_connector helper.
PATCH 8-10 are to move the panel/bridge parsing to the Analogix side.
PATCH 11-12 are preparations for apply panel_bridge helper.
PATCH 13 is to apply the panel_bridge helper.
Damon Ding (13):
drm/bridge: analogix_dp: Formalize the struct analogix_dp_device
drm/bridge: analogix_dp: Move &drm_bridge_funcs.mode_set to
&drm_bridge_funcs.atomic_enable
drm/bridge: analogix_dp: Add &analogix_dp_plat_data.next_bridge
drm/exynos: exynos_dp: Remove &exynos_dp_device.ptn_bridge
drm/bridge: exynos_dp: Remove unused &exynos_dp_device.connector
drm/bridge: analogix_dp: Remove redundant
&analogix_dp_plat_data.skip_connector
drm/bridge: analogix_dp: Apply drm_bridge_connector helper
drm/bridge: analogix_dp: Add new API analogix_dp_finish_probe()
drm/rockchip: analogix_dp: Apply analogix_dp_finish_probe()
drm/exynos: exynos_dp: Apply analogix_dp_finish_probe()
drm/bridge: analogix_dp: Remove panel disabling and enabling in
analogix_dp_set_bridge()
drm/bridge: analogix_dp: Remove bridge disabing and panel unpreparing
in analogix_dp_unbind()
drm/bridge: analogix_dp: Apply panel_bridge helper
.../drm/bridge/analogix/analogix_dp_core.c | 384 ++++++++++--------
.../drm/bridge/analogix/analogix_dp_core.h | 5 +-
drivers/gpu/drm/exynos/exynos_dp.c | 48 +--
.../gpu/drm/rockchip/analogix_dp-rockchip.c | 49 +--
include/drm/bridge/analogix_dp.h | 7 +-
5 files changed, 248 insertions(+), 245 deletions(-)
---
Changes in v2:
- Update Exynos DP driver synchronously.
- Move the panel/bridge parsing to the Analogix side.
Changes in v3:
- Rebase for the existing devm_drm_bridge_alloc() applying commit.
- Fix the typographical error of panel/bridge check in exynos_dp_bind().
- Squash all commits related to skip_connector deletion in both Exynos and
Analogix code into one.
- Apply panel_bridge helper to make the codes more concise.
- Fix the handing of bridge in analogix_dp_bridge_get_modes().
- Remove unnecessary parameter struct drm_connector* for callback
&analogix_dp_plat_data.attach().
- In order to decouple the connector driver and the bridge driver, move
the bridge connector initilization to the Rockchip and Exynos sides.
Changes in v4:
- Rebase for the applied &drm_bridge_funcs.detect() modification commit.
- Rename analogix_dp_find_panel_or_bridge() to analogix_dp_finish_probe().
- Drop the drmm_encoder_init() modification commit.
- Rename the &analogix_dp_plat_data.bridge to
&analogix_dp_plat_data.next_bridge.
--
2.34.1
On 14.08.2025 12:47, Damon Ding wrote: > PATCH 1 is a small format optimization for struct analogid_dp_device. > PATCH 2 is to perform mode setting in &drm_bridge_funcs.atomic_enable. > PATCH 3-6 are preparations for apply drm_bridge_connector helper. > PATCH 7 is to apply the drm_bridge_connector helper. > PATCH 8-10 are to move the panel/bridge parsing to the Analogix side. > PATCH 11-12 are preparations for apply panel_bridge helper. > PATCH 13 is to apply the panel_bridge helper. This series lacks 'select DRM_BRIDGE_CONNECTOR' in ExynosDP's Kconfig, so it causes build break: drivers/gpu/drm/exynos/exynos_dp.c:177: undefined reference to `drm_bridge_connector_init' make[2]: *** [scripts/Makefile.vmlinux:91: vmlinux] Error 1 After adding this dependency, the Exynos DP driver stops working. On Samsung Snow Chromebook I observed following issue: [ 4.534220] exynos-dp 145b0000.dp-controller: failed to attach following panel or bridge (-16) [ 4.543428] exynos-drm exynos-drm: failed to bind 145b0000.dp-controller (ops exynos_dp_ops): -16 [ 4.551775] exynos-drm exynos-drm: adev bind failed: -16 [ 4.556559] exynos-dp 145b0000.dp-controller: probe with driver exynos-dp failed with error -16 I will investigate details later in the evening. > Damon Ding (13): > drm/bridge: analogix_dp: Formalize the struct analogix_dp_device > drm/bridge: analogix_dp: Move &drm_bridge_funcs.mode_set to > &drm_bridge_funcs.atomic_enable > drm/bridge: analogix_dp: Add &analogix_dp_plat_data.next_bridge > drm/exynos: exynos_dp: Remove &exynos_dp_device.ptn_bridge > drm/bridge: exynos_dp: Remove unused &exynos_dp_device.connector > drm/bridge: analogix_dp: Remove redundant > &analogix_dp_plat_data.skip_connector > drm/bridge: analogix_dp: Apply drm_bridge_connector helper > drm/bridge: analogix_dp: Add new API analogix_dp_finish_probe() > drm/rockchip: analogix_dp: Apply analogix_dp_finish_probe() > drm/exynos: exynos_dp: Apply analogix_dp_finish_probe() > drm/bridge: analogix_dp: Remove panel disabling and enabling in > analogix_dp_set_bridge() > drm/bridge: analogix_dp: Remove bridge disabing and panel unpreparing > in analogix_dp_unbind() > drm/bridge: analogix_dp: Apply panel_bridge helper > > .../drm/bridge/analogix/analogix_dp_core.c | 384 ++++++++++-------- > .../drm/bridge/analogix/analogix_dp_core.h | 5 +- > drivers/gpu/drm/exynos/exynos_dp.c | 48 +-- > .../gpu/drm/rockchip/analogix_dp-rockchip.c | 49 +-- > include/drm/bridge/analogix_dp.h | 7 +- > 5 files changed, 248 insertions(+), 245 deletions(-) > > --- > > Changes in v2: > - Update Exynos DP driver synchronously. > - Move the panel/bridge parsing to the Analogix side. > > Changes in v3: > - Rebase for the existing devm_drm_bridge_alloc() applying commit. > - Fix the typographical error of panel/bridge check in exynos_dp_bind(). > - Squash all commits related to skip_connector deletion in both Exynos and > Analogix code into one. > - Apply panel_bridge helper to make the codes more concise. > - Fix the handing of bridge in analogix_dp_bridge_get_modes(). > - Remove unnecessary parameter struct drm_connector* for callback > &analogix_dp_plat_data.attach(). > - In order to decouple the connector driver and the bridge driver, move > the bridge connector initilization to the Rockchip and Exynos sides. > > Changes in v4: > - Rebase for the applied &drm_bridge_funcs.detect() modification commit. > - Rename analogix_dp_find_panel_or_bridge() to analogix_dp_finish_probe(). > - Drop the drmm_encoder_init() modification commit. > - Rename the &analogix_dp_plat_data.bridge to > &analogix_dp_plat_data.next_bridge. > Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
Hi Marek, On 2025/8/14 22:33, Marek Szyprowski wrote: > On 14.08.2025 12:47, Damon Ding wrote: >> PATCH 1 is a small format optimization for struct analogid_dp_device. >> PATCH 2 is to perform mode setting in &drm_bridge_funcs.atomic_enable. >> PATCH 3-6 are preparations for apply drm_bridge_connector helper. >> PATCH 7 is to apply the drm_bridge_connector helper. >> PATCH 8-10 are to move the panel/bridge parsing to the Analogix side. >> PATCH 11-12 are preparations for apply panel_bridge helper. >> PATCH 13 is to apply the panel_bridge helper. > > This series lacks 'select DRM_BRIDGE_CONNECTOR' in ExynosDP's Kconfig, > so it causes build break: > > drivers/gpu/drm/exynos/exynos_dp.c:177: undefined reference to > `drm_bridge_connector_init' > make[2]: *** [scripts/Makefile.vmlinux:91: vmlinux] Error 1 > > After adding this dependency, the Exynos DP driver stops working. On > Samsung Snow Chromebook I observed following issue: > > [ 4.534220] exynos-dp 145b0000.dp-controller: failed to attach > following panel or bridge (-16) > [ 4.543428] exynos-drm exynos-drm: failed to bind > 145b0000.dp-controller (ops exynos_dp_ops): -16 > [ 4.551775] exynos-drm exynos-drm: adev bind failed: -16 > [ 4.556559] exynos-dp 145b0000.dp-controller: probe with driver > exynos-dp failed with error -16 > > I will investigate details later in the evening. > Thanks for your review and test. :-) I found the Rockchip side also lacks 'select DRM_BRIDGE_CONNECTOR' in ROCKCHIP_ANALOGIX_DP's Kconfig. I will add the DRM_BRIDGE_CONNECTOR selection for both of them in the next version. >> Damon Ding (13): >> drm/bridge: analogix_dp: Formalize the struct analogix_dp_device >> drm/bridge: analogix_dp: Move &drm_bridge_funcs.mode_set to >> &drm_bridge_funcs.atomic_enable >> drm/bridge: analogix_dp: Add &analogix_dp_plat_data.next_bridge >> drm/exynos: exynos_dp: Remove &exynos_dp_device.ptn_bridge >> drm/bridge: exynos_dp: Remove unused &exynos_dp_device.connector >> drm/bridge: analogix_dp: Remove redundant >> &analogix_dp_plat_data.skip_connector >> drm/bridge: analogix_dp: Apply drm_bridge_connector helper >> drm/bridge: analogix_dp: Add new API analogix_dp_finish_probe() >> drm/rockchip: analogix_dp: Apply analogix_dp_finish_probe() >> drm/exynos: exynos_dp: Apply analogix_dp_finish_probe() >> drm/bridge: analogix_dp: Remove panel disabling and enabling in >> analogix_dp_set_bridge() >> drm/bridge: analogix_dp: Remove bridge disabing and panel unpreparing >> in analogix_dp_unbind() >> drm/bridge: analogix_dp: Apply panel_bridge helper >> >> .../drm/bridge/analogix/analogix_dp_core.c | 384 ++++++++++-------- >> .../drm/bridge/analogix/analogix_dp_core.h | 5 +- >> drivers/gpu/drm/exynos/exynos_dp.c | 48 +-- >> .../gpu/drm/rockchip/analogix_dp-rockchip.c | 49 +-- >> include/drm/bridge/analogix_dp.h | 7 +- >> 5 files changed, 248 insertions(+), 245 deletions(-) >> >> --- >> >> Changes in v2: >> - Update Exynos DP driver synchronously. >> - Move the panel/bridge parsing to the Analogix side. >> >> Changes in v3: >> - Rebase for the existing devm_drm_bridge_alloc() applying commit. >> - Fix the typographical error of panel/bridge check in exynos_dp_bind(). >> - Squash all commits related to skip_connector deletion in both Exynos and >> Analogix code into one. >> - Apply panel_bridge helper to make the codes more concise. >> - Fix the handing of bridge in analogix_dp_bridge_get_modes(). >> - Remove unnecessary parameter struct drm_connector* for callback >> &analogix_dp_plat_data.attach(). >> - In order to decouple the connector driver and the bridge driver, move >> the bridge connector initilization to the Rockchip and Exynos sides. >> >> Changes in v4: >> - Rebase for the applied &drm_bridge_funcs.detect() modification commit. >> - Rename analogix_dp_find_panel_or_bridge() to analogix_dp_finish_probe(). >> - Drop the drmm_encoder_init() modification commit. >> - Rename the &analogix_dp_plat_data.bridge to >> &analogix_dp_plat_data.next_bridge. >> > Best regards Best regards, Damon
On 14.08.2025 16:33, Marek Szyprowski wrote: > On 14.08.2025 12:47, Damon Ding wrote: >> PATCH 1 is a small format optimization for struct analogid_dp_device. >> PATCH 2 is to perform mode setting in &drm_bridge_funcs.atomic_enable. >> PATCH 3-6 are preparations for apply drm_bridge_connector helper. >> PATCH 7 is to apply the drm_bridge_connector helper. >> PATCH 8-10 are to move the panel/bridge parsing to the Analogix side. >> PATCH 11-12 are preparations for apply panel_bridge helper. >> PATCH 13 is to apply the panel_bridge helper. > > This series lacks 'select DRM_BRIDGE_CONNECTOR' in ExynosDP's Kconfig, > so it causes build break: > > drivers/gpu/drm/exynos/exynos_dp.c:177: undefined reference to > `drm_bridge_connector_init' > make[2]: *** [scripts/Makefile.vmlinux:91: vmlinux] Error 1 > > After adding this dependency, the Exynos DP driver stops working. On > Samsung Snow Chromebook I observed following issue: > > [ 4.534220] exynos-dp 145b0000.dp-controller: failed to attach > following panel or bridge (-16) > [ 4.543428] exynos-drm exynos-drm: failed to bind > 145b0000.dp-controller (ops exynos_dp_ops): -16 > [ 4.551775] exynos-drm exynos-drm: adev bind failed: -16 > [ 4.556559] exynos-dp 145b0000.dp-controller: probe with driver > exynos-dp failed with error -16 > > I will investigate details later in the evening. The failure is caused by trying to add plat_data->next_bridge twice (from exynos_dp's .attach callback, and from analogix' ->bind callback). Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
Hi Marek,
On 2025/8/15 5:16, Marek Szyprowski wrote:
>
> On 14.08.2025 16:33, Marek Szyprowski wrote:
>> On 14.08.2025 12:47, Damon Ding wrote:
>>> PATCH 1 is a small format optimization for struct analogid_dp_device.
>>> PATCH 2 is to perform mode setting in &drm_bridge_funcs.atomic_enable.
>>> PATCH 3-6 are preparations for apply drm_bridge_connector helper.
>>> PATCH 7 is to apply the drm_bridge_connector helper.
>>> PATCH 8-10 are to move the panel/bridge parsing to the Analogix side.
>>> PATCH 11-12 are preparations for apply panel_bridge helper.
>>> PATCH 13 is to apply the panel_bridge helper.
>>
>> This series lacks 'select DRM_BRIDGE_CONNECTOR' in ExynosDP's Kconfig,
>> so it causes build break:
>>
>> drivers/gpu/drm/exynos/exynos_dp.c:177: undefined reference to
>> `drm_bridge_connector_init'
>> make[2]: *** [scripts/Makefile.vmlinux:91: vmlinux] Error 1
>>
>> After adding this dependency, the Exynos DP driver stops working. On
>> Samsung Snow Chromebook I observed following issue:
>>
>> [ 4.534220] exynos-dp 145b0000.dp-controller: failed to attach
>> following panel or bridge (-16)
>> [ 4.543428] exynos-drm exynos-drm: failed to bind
>> 145b0000.dp-controller (ops exynos_dp_ops): -16
>> [ 4.551775] exynos-drm exynos-drm: adev bind failed: -16
>> [ 4.556559] exynos-dp 145b0000.dp-controller: probe with driver
>> exynos-dp failed with error -16
>>
>> I will investigate details later in the evening.
>
> The failure is caused by trying to add plat_data->next_bridge twice
> (from exynos_dp's .attach callback, and from analogix' ->bind callback).
>
>
> Best regards
I see. The bridge attachment for the next bridge was not well thought
out. It may be better to move panel_bridge addition a little forward and
remove next_bridge attachment on the Analogix side. Then, the Rockchip
side and Exynos side can do their own next_bridge attachment in
&analogix_dp_plat_data.attach() as they want.
Could you please help test the following modifications(they have been
tested on my RK3588S EVB1 Board) on the Samsung Snow Chromebook? ;-)
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index 0529bfb02884..8a9ce1f31678 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -1573,6 +1573,15 @@ int analogix_dp_bind(struct analogix_dp_device
*dp, struct drm_device *drm_dev)
return ret;
}
+ if (dp->plat_data->panel) {
+ dp->plat_data->next_bridge =
devm_drm_panel_bridge_add(dp->dev,
+
dp->plat_data->panel);
+ if (IS_ERR(dp->plat_data->next_bridge)) {
+ ret = PTR_ERR(bridge);
+ goto err_unregister_aux;
+ }
+ }
+
bridge->ops = DRM_BRIDGE_OP_DETECT |
DRM_BRIDGE_OP_EDID |
DRM_BRIDGE_OP_MODES;
@@ -1588,22 +1597,6 @@ int analogix_dp_bind(struct analogix_dp_device
*dp, struct drm_device *drm_dev)
goto err_unregister_aux;
}
- if (dp->plat_data->panel) {
- dp->plat_data->next_bridge =
devm_drm_panel_bridge_add(dp->dev,
-
dp->plat_data->panel);
- if (IS_ERR(dp->plat_data->next_bridge)) {
- ret = PTR_ERR(bridge);
- goto err_unregister_aux;
- }
- }
-
- ret = drm_bridge_attach(dp->encoder, dp->plat_data->next_bridge,
bridge,
- DRM_BRIDGE_ATTACH_NO_CONNECTOR);
- if (ret) {
- dev_err(dp->dev, "failed to attach following panel or
bridge (%d)\n", ret);
- goto err_unregister_aux;
- }
-
return 0;
err_unregister_aux:
diff --git a/drivers/gpu/drm/exynos/exynos_dp.c
b/drivers/gpu/drm/exynos/exynos_dp.c
index 80ba700d2964..d0422f940249 100644
--- a/drivers/gpu/drm/exynos/exynos_dp.c
+++ b/drivers/gpu/drm/exynos/exynos_dp.c
@@ -104,7 +104,7 @@ static int exynos_dp_bridge_attach(struct
analogix_dp_plat_data *plat_data,
/* Pre-empt DP connector creation if there's a bridge */
if (plat_data->next_bridge) {
ret = drm_bridge_attach(&dp->encoder,
plat_data->next_bridge, bridge,
- 0);
+ DRM_BRIDGE_ATTACH_NO_CONNECTOR);
if (ret)
return ret;
}
diff --git a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
index 0862b09a8be2..dfd32a79b94f 100644
--- a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
@@ -164,6 +164,24 @@ static int rockchip_dp_powerdown(struct
analogix_dp_plat_data *plat_data)
return 0;
}
+static int rockchip_dp_attach(struct analogix_dp_plat_data *plat_data,
+ struct drm_bridge *bridge)
+{
+ struct rockchip_dp_device *dp = pdata_encoder_to_dp(plat_data);
+ int ret;
+
+ if (plat_data->next_bridge) {
+ ret = drm_bridge_attach(&dp->encoder.encoder,
plat_data->next_bridge, bridge,
+ DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+ if (ret) {
+ dev_err(dp->dev, "failed to attach following
panel or bridge (%d)\n", ret);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
static int rockchip_dp_get_modes(struct analogix_dp_plat_data *plat_data,
struct drm_connector *connector)
{
@@ -478,6 +496,7 @@ static int rockchip_dp_probe(struct platform_device
*pdev)
dp->plat_data.dev_type = dp->data->chip_type;
dp->plat_data.power_on = rockchip_dp_poweron;
dp->plat_data.power_off = rockchip_dp_powerdown;
+ dp->plat_data.attach = rockchip_dp_attach;
dp->plat_data.get_modes = rockchip_dp_get_modes;
dp->plat_data.ops = &rockchip_dp_component_ops;
Best regards,
Damon
On 15.08.2025 04:59, Damon Ding wrote:
> On 2025/8/15 5:16, Marek Szyprowski wrote:
>> On 14.08.2025 16:33, Marek Szyprowski wrote:
>>> On 14.08.2025 12:47, Damon Ding wrote:
>>>> PATCH 1 is a small format optimization for struct analogid_dp_device.
>>>> PATCH 2 is to perform mode setting in &drm_bridge_funcs.atomic_enable.
>>>> PATCH 3-6 are preparations for apply drm_bridge_connector helper.
>>>> PATCH 7 is to apply the drm_bridge_connector helper.
>>>> PATCH 8-10 are to move the panel/bridge parsing to the Analogix side.
>>>> PATCH 11-12 are preparations for apply panel_bridge helper.
>>>> PATCH 13 is to apply the panel_bridge helper.
>>>
>>> This series lacks 'select DRM_BRIDGE_CONNECTOR' in ExynosDP's Kconfig,
>>> so it causes build break:
>>>
>>> drivers/gpu/drm/exynos/exynos_dp.c:177: undefined reference to
>>> `drm_bridge_connector_init'
>>> make[2]: *** [scripts/Makefile.vmlinux:91: vmlinux] Error 1
>>>
>>> After adding this dependency, the Exynos DP driver stops working. On
>>> Samsung Snow Chromebook I observed following issue:
>>>
>>> [ 4.534220] exynos-dp 145b0000.dp-controller: failed to attach
>>> following panel or bridge (-16)
>>> [ 4.543428] exynos-drm exynos-drm: failed to bind
>>> 145b0000.dp-controller (ops exynos_dp_ops): -16
>>> [ 4.551775] exynos-drm exynos-drm: adev bind failed: -16
>>> [ 4.556559] exynos-dp 145b0000.dp-controller: probe with driver
>>> exynos-dp failed with error -16
>>>
>>> I will investigate details later in the evening.
>>
>> The failure is caused by trying to add plat_data->next_bridge twice
>> (from exynos_dp's .attach callback, and from analogix' ->bind callback).
>>
>>
>> Best regards
>
> I see. The bridge attachment for the next bridge was not well thought
> out. It may be better to move panel_bridge addition a little forward
> and remove next_bridge attachment on the Analogix side. Then, the
> Rockchip side and Exynos side can do their own next_bridge attachment
> in &analogix_dp_plat_data.attach() as they want.
>
> Could you please help test the following modifications(they have been
> tested on my RK3588S EVB1 Board) on the Samsung Snow Chromebook? ;-)
Assuming that I properly applied the malformed diff, it doesn't solve
all the issues. There are no errors reported though, but the display
chain doesn't work and no valid mode is reported:
# dmesg | grep drm
[ 3.384992] [drm] Initialized panfrost 1.4.0 for 11800000.gpu on minor 0
[ 4.487739] [drm] Exynos DRM: using 14400000.fimd device for DMA
mapping operations
[ 4.494202] exynos-drm exynos-drm: bound 14400000.fimd (ops
fimd_component_ops)
[ 4.502374] exynos-drm exynos-drm: bound 14450000.mixer (ops
mixer_component_ops)
[ 4.511930] exynos-drm exynos-drm: bound 145b0000.dp-controller (ops
exynos_dp_ops)
[ 4.518411] exynos-drm exynos-drm: bound 14530000.hdmi (ops
hdmi_component_ops)
[ 4.529628] [drm] Initialized exynos 1.1.0 for exynos-drm on minor 1
[ 4.657434] exynos-drm exynos-drm: [drm] Cannot find any crtc or sizes
[ 4.925023] exynos-drm exynos-drm: [drm] Cannot find any crtc or sizes
# ./modetest -c -Mexynos
Connectors:
id encoder status name size (mm) modes
encoders
69 0 disconnected LVDS-1 0x0 0 68
props:
1 EDID:
flags: immutable blob
blobs:
value:
2 DPMS:
flags: enum
enums: On=0 Standby=1 Suspend=2 Off=3
value: 0
5 link-status:
flags: enum
enums: Good=0 Bad=1
value: 0
6 non-desktop:
flags: immutable range
values: 0 1
value: 0
4 TILE:
flags: immutable blob
blobs:
value:
71 0 disconnected HDMI-A-1 0x0 0 70
props:
1 EDID:
flags: immutable blob
blobs:
value:
2 DPMS:
flags: enum
enums: On=0 Standby=1 Suspend=2 Off=3
value: 0
5 link-status:
flags: enum
enums: Good=0 Bad=1
value: 0
6 non-desktop:
flags: immutable range
values: 0 1
value: 0
4 TILE:
flags: immutable blob
blobs:
value:
I will investigate details later this week.
>
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> index 0529bfb02884..8a9ce1f31678 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> @@ -1573,6 +1573,15 @@ int analogix_dp_bind(struct analogix_dp_device
> *dp, struct drm_device *drm_dev)
> return ret;
> }
>
> + if (dp->plat_data->panel) {
> + dp->plat_data->next_bridge =
> devm_drm_panel_bridge_add(dp->dev,
> + dp->plat_data->panel);
> + if (IS_ERR(dp->plat_data->next_bridge)) {
> + ret = PTR_ERR(bridge);
> + goto err_unregister_aux;
> + }
> + }
> +
> bridge->ops = DRM_BRIDGE_OP_DETECT |
> DRM_BRIDGE_OP_EDID |
> DRM_BRIDGE_OP_MODES;
> @@ -1588,22 +1597,6 @@ int analogix_dp_bind(struct analogix_dp_device
> *dp, struct drm_device *drm_dev)
> goto err_unregister_aux;
> }
>
> - if (dp->plat_data->panel) {
> - dp->plat_data->next_bridge =
> devm_drm_panel_bridge_add(dp->dev,
> - dp->plat_data->panel);
> - if (IS_ERR(dp->plat_data->next_bridge)) {
> - ret = PTR_ERR(bridge);
> - goto err_unregister_aux;
> - }
> - }
> -
> - ret = drm_bridge_attach(dp->encoder,
> dp->plat_data->next_bridge, bridge,
> - DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> - if (ret) {
> - dev_err(dp->dev, "failed to attach following panel or
> bridge (%d)\n", ret);
> - goto err_unregister_aux;
> - }
> -
> return 0;
>
> err_unregister_aux:
> diff --git a/drivers/gpu/drm/exynos/exynos_dp.c
> b/drivers/gpu/drm/exynos/exynos_dp.c
> index 80ba700d2964..d0422f940249 100644
> --- a/drivers/gpu/drm/exynos/exynos_dp.c
> +++ b/drivers/gpu/drm/exynos/exynos_dp.c
> @@ -104,7 +104,7 @@ static int exynos_dp_bridge_attach(struct
> analogix_dp_plat_data *plat_data,
> /* Pre-empt DP connector creation if there's a bridge */
> if (plat_data->next_bridge) {
> ret = drm_bridge_attach(&dp->encoder,
> plat_data->next_bridge, bridge,
> - 0);
> + DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> if (ret)
> return ret;
> }
> diff --git a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
> b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
> index 0862b09a8be2..dfd32a79b94f 100644
> --- a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
> +++ b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
> @@ -164,6 +164,24 @@ static int rockchip_dp_powerdown(struct
> analogix_dp_plat_data *plat_data)
> return 0;
> }
>
> +static int rockchip_dp_attach(struct analogix_dp_plat_data *plat_data,
> + struct drm_bridge *bridge)
> +{
> + struct rockchip_dp_device *dp = pdata_encoder_to_dp(plat_data);
> + int ret;
> +
> + if (plat_data->next_bridge) {
> + ret = drm_bridge_attach(&dp->encoder.encoder,
> plat_data->next_bridge, bridge,
> + DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> + if (ret) {
> + dev_err(dp->dev, "failed to attach following
> panel or bridge (%d)\n", ret);
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
> +
> static int rockchip_dp_get_modes(struct analogix_dp_plat_data
> *plat_data,
> struct drm_connector *connector)
> {
> @@ -478,6 +496,7 @@ static int rockchip_dp_probe(struct
> platform_device *pdev)
> dp->plat_data.dev_type = dp->data->chip_type;
> dp->plat_data.power_on = rockchip_dp_poweron;
> dp->plat_data.power_off = rockchip_dp_powerdown;
> + dp->plat_data.attach = rockchip_dp_attach;
> dp->plat_data.get_modes = rockchip_dp_get_modes;
> dp->plat_data.ops = &rockchip_dp_component_ops;
>
>
> Best regards,
> Damon
>
>
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
Hi Marek,
On 8/20/2025 5:20 AM, Marek Szyprowski wrote:
> On 15.08.2025 04:59, Damon Ding wrote:
>> On 2025/8/15 5:16, Marek Szyprowski wrote:
>>> On 14.08.2025 16:33, Marek Szyprowski wrote:
>>>> On 14.08.2025 12:47, Damon Ding wrote:
>>>>> PATCH 1 is a small format optimization for struct analogid_dp_device.
>>>>> PATCH 2 is to perform mode setting in &drm_bridge_funcs.atomic_enable.
>>>>> PATCH 3-6 are preparations for apply drm_bridge_connector helper.
>>>>> PATCH 7 is to apply the drm_bridge_connector helper.
>>>>> PATCH 8-10 are to move the panel/bridge parsing to the Analogix side.
>>>>> PATCH 11-12 are preparations for apply panel_bridge helper.
>>>>> PATCH 13 is to apply the panel_bridge helper.
>>>>
>>>> This series lacks 'select DRM_BRIDGE_CONNECTOR' in ExynosDP's Kconfig,
>>>> so it causes build break:
>>>>
>>>> drivers/gpu/drm/exynos/exynos_dp.c:177: undefined reference to
>>>> `drm_bridge_connector_init'
>>>> make[2]: *** [scripts/Makefile.vmlinux:91: vmlinux] Error 1
>>>>
>>>> After adding this dependency, the Exynos DP driver stops working. On
>>>> Samsung Snow Chromebook I observed following issue:
>>>>
>>>> [ 4.534220] exynos-dp 145b0000.dp-controller: failed to attach
>>>> following panel or bridge (-16)
>>>> [ 4.543428] exynos-drm exynos-drm: failed to bind
>>>> 145b0000.dp-controller (ops exynos_dp_ops): -16
>>>> [ 4.551775] exynos-drm exynos-drm: adev bind failed: -16
>>>> [ 4.556559] exynos-dp 145b0000.dp-controller: probe with driver
>>>> exynos-dp failed with error -16
>>>>
>>>> I will investigate details later in the evening.
>>>
>>> The failure is caused by trying to add plat_data->next_bridge twice
>>> (from exynos_dp's .attach callback, and from analogix' ->bind callback).
>>>
>>>
>>> Best regards
>>
>> I see. The bridge attachment for the next bridge was not well thought
>> out. It may be better to move panel_bridge addition a little forward
>> and remove next_bridge attachment on the Analogix side. Then, the
>> Rockchip side and Exynos side can do their own next_bridge attachment
>> in &analogix_dp_plat_data.attach() as they want.
>>
>> Could you please help test the following modifications(they have been
>> tested on my RK3588S EVB1 Board) on the Samsung Snow Chromebook? ;-)
>
> Assuming that I properly applied the malformed diff, it doesn't solve
> all the issues. There are no errors reported though, but the display
> chain doesn't work and no valid mode is reported:
>
> # dmesg | grep drm
> [ 3.384992] [drm] Initialized panfrost 1.4.0 for 11800000.gpu on minor 0
> [ 4.487739] [drm] Exynos DRM: using 14400000.fimd device for DMA
> mapping operations
> [ 4.494202] exynos-drm exynos-drm: bound 14400000.fimd (ops
> fimd_component_ops)
> [ 4.502374] exynos-drm exynos-drm: bound 14450000.mixer (ops
> mixer_component_ops)
> [ 4.511930] exynos-drm exynos-drm: bound 145b0000.dp-controller (ops
> exynos_dp_ops)
> [ 4.518411] exynos-drm exynos-drm: bound 14530000.hdmi (ops
> hdmi_component_ops)
> [ 4.529628] [drm] Initialized exynos 1.1.0 for exynos-drm on minor 1
> [ 4.657434] exynos-drm exynos-drm: [drm] Cannot find any crtc or sizes
> [ 4.925023] exynos-drm exynos-drm: [drm] Cannot find any crtc or sizes
>
> # ./modetest -c -Mexynos
> Connectors:
> id encoder status name size (mm) modes
> encoders
> 69 0 disconnected LVDS-1 0x0 0 68
> props:
> 1 EDID:
> flags: immutable blob
> blobs:
>
> value:
> 2 DPMS:
> flags: enum
> enums: On=0 Standby=1 Suspend=2 Off=3
> value: 0
> 5 link-status:
> flags: enum
> enums: Good=0 Bad=1
> value: 0
> 6 non-desktop:
> flags: immutable range
> values: 0 1
> value: 0
> 4 TILE:
> flags: immutable blob
> blobs:
>
> value:
> 71 0 disconnected HDMI-A-1 0x0 0 70
> props:
> 1 EDID:
> flags: immutable blob
> blobs:
>
> value:
> 2 DPMS:
> flags: enum
> enums: On=0 Standby=1 Suspend=2 Off=3
> value: 0
> 5 link-status:
> flags: enum
> enums: Good=0 Bad=1
> value: 0
> 6 non-desktop:
> flags: immutable range
> values: 0 1
> value: 0
> 4 TILE:
> flags: immutable blob
> blobs:
>
> value:
>
>
> I will investigate details later this week.
>
Could you please provide the related DTS file for the test? I will also
try to find out the reason for this unexpected issue. ;-)
>
>>
>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> index 0529bfb02884..8a9ce1f31678 100644
>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> @@ -1573,6 +1573,15 @@ int analogix_dp_bind(struct analogix_dp_device
>> *dp, struct drm_device *drm_dev)
>> return ret;
>> }
>>
>> + if (dp->plat_data->panel) {
>> + dp->plat_data->next_bridge =
>> devm_drm_panel_bridge_add(dp->dev,
>> + dp->plat_data->panel);
>> + if (IS_ERR(dp->plat_data->next_bridge)) {
>> + ret = PTR_ERR(bridge);
>> + goto err_unregister_aux;
>> + }
>> + }
>> +
>> bridge->ops = DRM_BRIDGE_OP_DETECT |
>> DRM_BRIDGE_OP_EDID |
>> DRM_BRIDGE_OP_MODES;
>> @@ -1588,22 +1597,6 @@ int analogix_dp_bind(struct analogix_dp_device
>> *dp, struct drm_device *drm_dev)
>> goto err_unregister_aux;
>> }
>>
>> - if (dp->plat_data->panel) {
>> - dp->plat_data->next_bridge =
>> devm_drm_panel_bridge_add(dp->dev,
>> - dp->plat_data->panel);
>> - if (IS_ERR(dp->plat_data->next_bridge)) {
>> - ret = PTR_ERR(bridge);
>> - goto err_unregister_aux;
>> - }
>> - }
>> -
>> - ret = drm_bridge_attach(dp->encoder,
>> dp->plat_data->next_bridge, bridge,
>> - DRM_BRIDGE_ATTACH_NO_CONNECTOR);
>> - if (ret) {
>> - dev_err(dp->dev, "failed to attach following panel or
>> bridge (%d)\n", ret);
>> - goto err_unregister_aux;
>> - }
>> -
>> return 0;
>>
>> err_unregister_aux:
>> diff --git a/drivers/gpu/drm/exynos/exynos_dp.c
>> b/drivers/gpu/drm/exynos/exynos_dp.c
>> index 80ba700d2964..d0422f940249 100644
>> --- a/drivers/gpu/drm/exynos/exynos_dp.c
>> +++ b/drivers/gpu/drm/exynos/exynos_dp.c
>> @@ -104,7 +104,7 @@ static int exynos_dp_bridge_attach(struct
>> analogix_dp_plat_data *plat_data,
>> /* Pre-empt DP connector creation if there's a bridge */
>> if (plat_data->next_bridge) {
>> ret = drm_bridge_attach(&dp->encoder,
>> plat_data->next_bridge, bridge,
>> - 0);
>> + DRM_BRIDGE_ATTACH_NO_CONNECTOR);
>> if (ret)
>> return ret;
>> }
>> diff --git a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
>> b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
>> index 0862b09a8be2..dfd32a79b94f 100644
>> --- a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
>> +++ b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
>> @@ -164,6 +164,24 @@ static int rockchip_dp_powerdown(struct
>> analogix_dp_plat_data *plat_data)
>> return 0;
>> }
>>
>> +static int rockchip_dp_attach(struct analogix_dp_plat_data *plat_data,
>> + struct drm_bridge *bridge)
>> +{
>> + struct rockchip_dp_device *dp = pdata_encoder_to_dp(plat_data);
>> + int ret;
>> +
>> + if (plat_data->next_bridge) {
>> + ret = drm_bridge_attach(&dp->encoder.encoder,
>> plat_data->next_bridge, bridge,
>> + DRM_BRIDGE_ATTACH_NO_CONNECTOR);
>> + if (ret) {
>> + dev_err(dp->dev, "failed to attach following
>> panel or bridge (%d)\n", ret);
>> + return ret;
>> + }
>> + }
>> +
>> + return 0;
>> +}
>> +
>> static int rockchip_dp_get_modes(struct analogix_dp_plat_data
>> *plat_data,
>> struct drm_connector *connector)
>> {
>> @@ -478,6 +496,7 @@ static int rockchip_dp_probe(struct
>> platform_device *pdev)
>> dp->plat_data.dev_type = dp->data->chip_type;
>> dp->plat_data.power_on = rockchip_dp_poweron;
>> dp->plat_data.power_off = rockchip_dp_powerdown;
>> + dp->plat_data.attach = rockchip_dp_attach;
>> dp->plat_data.get_modes = rockchip_dp_get_modes;
>> dp->plat_data.ops = &rockchip_dp_component_ops;
>>
>>
Best regards,
Damon
On 29.08.2025 10:08, Damon Ding wrote: > On 8/20/2025 5:20 AM, Marek Szyprowski wrote: >> On 15.08.2025 04:59, Damon Ding wrote: >>> On 2025/8/15 5:16, Marek Szyprowski wrote: >>>> On 14.08.2025 16:33, Marek Szyprowski wrote: >>>>> On 14.08.2025 12:47, Damon Ding wrote: >>>>>> PATCH 1 is a small format optimization for struct >>>>>> analogid_dp_device. >>>>>> PATCH 2 is to perform mode setting in >>>>>> &drm_bridge_funcs.atomic_enable. >>>>>> PATCH 3-6 are preparations for apply drm_bridge_connector helper. >>>>>> PATCH 7 is to apply the drm_bridge_connector helper. >>>>>> PATCH 8-10 are to move the panel/bridge parsing to the Analogix >>>>>> side. >>>>>> PATCH 11-12 are preparations for apply panel_bridge helper. >>>>>> PATCH 13 is to apply the panel_bridge helper. >>>>> >>>>> This series lacks 'select DRM_BRIDGE_CONNECTOR' in ExynosDP's >>>>> Kconfig, >>>>> so it causes build break: >>>>> >>>>> drivers/gpu/drm/exynos/exynos_dp.c:177: undefined reference to >>>>> `drm_bridge_connector_init' >>>>> make[2]: *** [scripts/Makefile.vmlinux:91: vmlinux] Error 1 >>>>> >>>>> After adding this dependency, the Exynos DP driver stops working. On >>>>> Samsung Snow Chromebook I observed following issue: >>>>> >>>>> [ 4.534220] exynos-dp 145b0000.dp-controller: failed to attach >>>>> following panel or bridge (-16) >>>>> [ 4.543428] exynos-drm exynos-drm: failed to bind >>>>> 145b0000.dp-controller (ops exynos_dp_ops): -16 >>>>> [ 4.551775] exynos-drm exynos-drm: adev bind failed: -16 >>>>> [ 4.556559] exynos-dp 145b0000.dp-controller: probe with driver >>>>> exynos-dp failed with error -16 >>>>> >>>>> I will investigate details later in the evening. >>>> >>>> The failure is caused by trying to add plat_data->next_bridge twice >>>> (from exynos_dp's .attach callback, and from analogix' ->bind >>>> callback). >>>> >>>> >>>> Best regards >>> >>> I see. The bridge attachment for the next bridge was not well thought >>> out. It may be better to move panel_bridge addition a little forward >>> and remove next_bridge attachment on the Analogix side. Then, the >>> Rockchip side and Exynos side can do their own next_bridge attachment >>> in &analogix_dp_plat_data.attach() as they want. >>> >>> Could you please help test the following modifications(they have been >>> tested on my RK3588S EVB1 Board) on the Samsung Snow Chromebook? ;-) >> >> Assuming that I properly applied the malformed diff, it doesn't solve >> all the issues. There are no errors reported though, but the display >> chain doesn't work and no valid mode is reported: >> >> # dmesg | grep drm >> [ 3.384992] [drm] Initialized panfrost 1.4.0 for 11800000.gpu on >> minor 0 >> [ 4.487739] [drm] Exynos DRM: using 14400000.fimd device for DMA >> mapping operations >> [ 4.494202] exynos-drm exynos-drm: bound 14400000.fimd (ops >> fimd_component_ops) >> [ 4.502374] exynos-drm exynos-drm: bound 14450000.mixer (ops >> mixer_component_ops) >> [ 4.511930] exynos-drm exynos-drm: bound 145b0000.dp-controller (ops >> exynos_dp_ops) >> [ 4.518411] exynos-drm exynos-drm: bound 14530000.hdmi (ops >> hdmi_component_ops) >> [ 4.529628] [drm] Initialized exynos 1.1.0 for exynos-drm on minor 1 >> [ 4.657434] exynos-drm exynos-drm: [drm] Cannot find any crtc or >> sizes >> [ 4.925023] exynos-drm exynos-drm: [drm] Cannot find any crtc or >> sizes >> >> # ./modetest -c -Mexynos >> Connectors: >> id encoder status name size (mm) modes >> encoders >> 69 0 disconnected LVDS-1 0x0 0 >> 68 >> props: >> 1 EDID: >> flags: immutable blob >> blobs: >> >> value: >> 2 DPMS: >> flags: enum >> enums: On=0 Standby=1 Suspend=2 Off=3 >> value: 0 >> 5 link-status: >> flags: enum >> enums: Good=0 Bad=1 >> value: 0 >> 6 non-desktop: >> flags: immutable range >> values: 0 1 >> value: 0 >> 4 TILE: >> flags: immutable blob >> blobs: >> >> value: >> 71 0 disconnected HDMI-A-1 0x0 0 >> 70 >> props: >> 1 EDID: >> flags: immutable blob >> blobs: >> >> value: >> 2 DPMS: >> flags: enum >> enums: On=0 Standby=1 Suspend=2 Off=3 >> value: 0 >> 5 link-status: >> flags: enum >> enums: Good=0 Bad=1 >> value: 0 >> 6 non-desktop: >> flags: immutable range >> values: 0 1 >> value: 0 >> 4 TILE: >> flags: immutable blob >> blobs: >> >> value: >> >> >> I will investigate details later this week. >> > > Could you please provide the related DTS file for the test? I will > also try to find out the reason for this unexpected issue. ;-) Unfortunately I didn't find enough time to debug this further. The above log is from Samsung Snow Chromebook, arch/arm/boot/dts/samsung/exynos5250-snow.dts > ... Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
Hi Marek,
On 8/29/2025 4:23 PM, Marek Szyprowski wrote:
> On 29.08.2025 10:08, Damon Ding wrote:
>> On 8/20/2025 5:20 AM, Marek Szyprowski wrote:
>>> On 15.08.2025 04:59, Damon Ding wrote:
>>>> On 2025/8/15 5:16, Marek Szyprowski wrote:
>>>>> On 14.08.2025 16:33, Marek Szyprowski wrote:
>>>>>> On 14.08.2025 12:47, Damon Ding wrote:
>>>>>>> PATCH 1 is a small format optimization for struct
>>>>>>> analogid_dp_device.
>>>>>>> PATCH 2 is to perform mode setting in
>>>>>>> &drm_bridge_funcs.atomic_enable.
>>>>>>> PATCH 3-6 are preparations for apply drm_bridge_connector helper.
>>>>>>> PATCH 7 is to apply the drm_bridge_connector helper.
>>>>>>> PATCH 8-10 are to move the panel/bridge parsing to the Analogix
>>>>>>> side.
>>>>>>> PATCH 11-12 are preparations for apply panel_bridge helper.
>>>>>>> PATCH 13 is to apply the panel_bridge helper.
>>>>>>
>>>>>> This series lacks 'select DRM_BRIDGE_CONNECTOR' in ExynosDP's
>>>>>> Kconfig,
>>>>>> so it causes build break:
>>>>>>
>>>>>> drivers/gpu/drm/exynos/exynos_dp.c:177: undefined reference to
>>>>>> `drm_bridge_connector_init'
>>>>>> make[2]: *** [scripts/Makefile.vmlinux:91: vmlinux] Error 1
>>>>>>
>>>>>> After adding this dependency, the Exynos DP driver stops working. On
>>>>>> Samsung Snow Chromebook I observed following issue:
>>>>>>
>>>>>> [ 4.534220] exynos-dp 145b0000.dp-controller: failed to attach
>>>>>> following panel or bridge (-16)
>>>>>> [ 4.543428] exynos-drm exynos-drm: failed to bind
>>>>>> 145b0000.dp-controller (ops exynos_dp_ops): -16
>>>>>> [ 4.551775] exynos-drm exynos-drm: adev bind failed: -16
>>>>>> [ 4.556559] exynos-dp 145b0000.dp-controller: probe with driver
>>>>>> exynos-dp failed with error -16
>>>>>>
>>>>>> I will investigate details later in the evening.
>>>>>
>>>>> The failure is caused by trying to add plat_data->next_bridge twice
>>>>> (from exynos_dp's .attach callback, and from analogix' ->bind
>>>>> callback).
>>>>>
>>>>>
>>>>> Best regards
>>>>
>>>> I see. The bridge attachment for the next bridge was not well thought
>>>> out. It may be better to move panel_bridge addition a little forward
>>>> and remove next_bridge attachment on the Analogix side. Then, the
>>>> Rockchip side and Exynos side can do their own next_bridge attachment
>>>> in &analogix_dp_plat_data.attach() as they want.
>>>>
>>>> Could you please help test the following modifications(they have been
>>>> tested on my RK3588S EVB1 Board) on the Samsung Snow Chromebook? ;-)
>>>
>>> Assuming that I properly applied the malformed diff, it doesn't solve
>>> all the issues. There are no errors reported though, but the display
>>> chain doesn't work and no valid mode is reported:
>>>
>>> # dmesg | grep drm
>>> [ 3.384992] [drm] Initialized panfrost 1.4.0 for 11800000.gpu on
>>> minor 0
>>> [ 4.487739] [drm] Exynos DRM: using 14400000.fimd device for DMA
>>> mapping operations
>>> [ 4.494202] exynos-drm exynos-drm: bound 14400000.fimd (ops
>>> fimd_component_ops)
>>> [ 4.502374] exynos-drm exynos-drm: bound 14450000.mixer (ops
>>> mixer_component_ops)
>>> [ 4.511930] exynos-drm exynos-drm: bound 145b0000.dp-controller (ops
>>> exynos_dp_ops)
>>> [ 4.518411] exynos-drm exynos-drm: bound 14530000.hdmi (ops
>>> hdmi_component_ops)
>>> [ 4.529628] [drm] Initialized exynos 1.1.0 for exynos-drm on minor 1
>>> [ 4.657434] exynos-drm exynos-drm: [drm] Cannot find any crtc or
>>> sizes
>>> [ 4.925023] exynos-drm exynos-drm: [drm] Cannot find any crtc or
>>> sizes
>>>
>>> # ./modetest -c -Mexynos
>>> Connectors:
>>> id encoder status name size (mm) modes
>>> encoders
>>> 69 0 disconnected LVDS-1 0x0 0
>>> 68
>>> props:
>>> 1 EDID:
>>> flags: immutable blob
>>> blobs:
>>>
>>> value:
>>> 2 DPMS:
>>> flags: enum
>>> enums: On=0 Standby=1 Suspend=2 Off=3
>>> value: 0
>>> 5 link-status:
>>> flags: enum
>>> enums: Good=0 Bad=1
>>> value: 0
>>> 6 non-desktop:
>>> flags: immutable range
>>> values: 0 1
>>> value: 0
>>> 4 TILE:
>>> flags: immutable blob
>>> blobs:
>>>
>>> value:
>>> 71 0 disconnected HDMI-A-1 0x0 0
>>> 70
>>> props:
>>> 1 EDID:
>>> flags: immutable blob
>>> blobs:
>>>
>>> value:
>>> 2 DPMS:
>>> flags: enum
>>> enums: On=0 Standby=1 Suspend=2 Off=3
>>> value: 0
>>> 5 link-status:
>>> flags: enum
>>> enums: Good=0 Bad=1
>>> value: 0
>>> 6 non-desktop:
>>> flags: immutable range
>>> values: 0 1
>>> value: 0
>>> 4 TILE:
>>> flags: immutable blob
>>> blobs:
>>>
>>> value:
>>>
>>>
>>> I will investigate details later this week.
>>>
>>
>> Could you please provide the related DTS file for the test? I will
>> also try to find out the reason for this unexpected issue. ;-)
>
> Unfortunately I didn't find enough time to debug this further. The above
> log is from Samsung Snow Chromebook,
> arch/arm/boot/dts/samsung/exynos5250-snow.dts
>
>
I compare the differences in the following display path before and after
this patch series:
exynos_dp -> nxp-ptn3460 -> panel "auo,b116xw03"
The issue is likely caused by the &drm_connector_funcs.detect() related
logic. Before this patch series, the nxp-ptn3460 connector is always
connector_status_connected because there is not available
&drm_connector_funcs.detect(). After it, the DRM_BRIDGE_OP_DETECT flag
make the connection status depend on analogix_dp_bridge_detect().
Could you please add the following patches additionally and try again?
(Not the final solution, just validation)
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index a93ff8f0a468..355911c47354 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -1491,9 +1491,11 @@ int analogix_dp_bind(struct analogix_dp_device
*dp, struct drm_device *drm_dev)
}
}
- bridge->ops = DRM_BRIDGE_OP_DETECT |
- DRM_BRIDGE_OP_EDID |
+ bridge->ops = DRM_BRIDGE_OP_EDID |
DRM_BRIDGE_OP_MODES;
+ if (drm_bridge_is_panel(dp->plat_data->next_bridge))
+ bridge->ops |= DRM_BRIDGE_OP_DETECT;
+
bridge->of_node = dp->dev->of_node;
bridge->type = DRM_MODE_CONNECTOR_eDP;
ret = devm_drm_bridge_add(dp->dev, &dp->bridge);
Best regards,
Damon
On 01.09.2025 05:41, Damon Ding wrote: > On 8/29/2025 4:23 PM, Marek Szyprowski wrote: >> On 29.08.2025 10:08, Damon Ding wrote: >>> On 8/20/2025 5:20 AM, Marek Szyprowski wrote: >>>> On 15.08.2025 04:59, Damon Ding wrote: >>>>> On 2025/8/15 5:16, Marek Szyprowski wrote: >>>>>> On 14.08.2025 16:33, Marek Szyprowski wrote: >>>>>>> On 14.08.2025 12:47, Damon Ding wrote: >>>>>>>> PATCH 1 is a small format optimization for struct >>>>>>>> analogid_dp_device. >>>>>>>> PATCH 2 is to perform mode setting in >>>>>>>> &drm_bridge_funcs.atomic_enable. >>>>>>>> PATCH 3-6 are preparations for apply drm_bridge_connector helper. >>>>>>>> PATCH 7 is to apply the drm_bridge_connector helper. >>>>>>>> PATCH 8-10 are to move the panel/bridge parsing to the Analogix >>>>>>>> side. >>>>>>>> PATCH 11-12 are preparations for apply panel_bridge helper. >>>>>>>> PATCH 13 is to apply the panel_bridge helper. >>>>>>> >>>>>>> This series lacks 'select DRM_BRIDGE_CONNECTOR' in ExynosDP's >>>>>>> Kconfig, >>>>>>> so it causes build break: >>>>>>> >>>>>>> drivers/gpu/drm/exynos/exynos_dp.c:177: undefined reference to >>>>>>> `drm_bridge_connector_init' >>>>>>> make[2]: *** [scripts/Makefile.vmlinux:91: vmlinux] Error 1 >>>>>>> >>>>>>> After adding this dependency, the Exynos DP driver stops >>>>>>> working. On >>>>>>> Samsung Snow Chromebook I observed following issue: >>>>>>> >>>>>>> [ 4.534220] exynos-dp 145b0000.dp-controller: failed to attach >>>>>>> following panel or bridge (-16) >>>>>>> [ 4.543428] exynos-drm exynos-drm: failed to bind >>>>>>> 145b0000.dp-controller (ops exynos_dp_ops): -16 >>>>>>> [ 4.551775] exynos-drm exynos-drm: adev bind failed: -16 >>>>>>> [ 4.556559] exynos-dp 145b0000.dp-controller: probe with driver >>>>>>> exynos-dp failed with error -16 >>>>>>> >>>>>>> I will investigate details later in the evening. >>>>>> >>>>>> The failure is caused by trying to add plat_data->next_bridge twice >>>>>> (from exynos_dp's .attach callback, and from analogix' ->bind >>>>>> callback). >>>>>> >>>>>> >>>>>> Best regards >>>>> >>>>> I see. The bridge attachment for the next bridge was not well thought >>>>> out. It may be better to move panel_bridge addition a little forward >>>>> and remove next_bridge attachment on the Analogix side. Then, the >>>>> Rockchip side and Exynos side can do their own next_bridge attachment >>>>> in &analogix_dp_plat_data.attach() as they want. >>>>> >>>>> Could you please help test the following modifications(they have been >>>>> tested on my RK3588S EVB1 Board) on the Samsung Snow Chromebook? ;-) >>>> >>>> Assuming that I properly applied the malformed diff, it doesn't solve >>>> all the issues. There are no errors reported though, but the display >>>> chain doesn't work and no valid mode is reported: >>>> >>>> # dmesg | grep drm >>>> [ 3.384992] [drm] Initialized panfrost 1.4.0 for 11800000.gpu on >>>> minor 0 >>>> [ 4.487739] [drm] Exynos DRM: using 14400000.fimd device for DMA >>>> mapping operations >>>> [ 4.494202] exynos-drm exynos-drm: bound 14400000.fimd (ops >>>> fimd_component_ops) >>>> [ 4.502374] exynos-drm exynos-drm: bound 14450000.mixer (ops >>>> mixer_component_ops) >>>> [ 4.511930] exynos-drm exynos-drm: bound 145b0000.dp-controller >>>> (ops >>>> exynos_dp_ops) >>>> [ 4.518411] exynos-drm exynos-drm: bound 14530000.hdmi (ops >>>> hdmi_component_ops) >>>> [ 4.529628] [drm] Initialized exynos 1.1.0 for exynos-drm on >>>> minor 1 >>>> [ 4.657434] exynos-drm exynos-drm: [drm] Cannot find any crtc or >>>> sizes >>>> [ 4.925023] exynos-drm exynos-drm: [drm] Cannot find any crtc or >>>> sizes >>>> >>>> # ./modetest -c -Mexynos >>>> Connectors: >>>> id encoder status name size (mm) modes >>>> encoders >>>> 69 0 disconnected LVDS-1 0x0 0 >>>> 68 >>>> props: >>>> 1 EDID: >>>> flags: immutable blob >>>> blobs: >>>> >>>> value: >>>> 2 DPMS: >>>> flags: enum >>>> enums: On=0 Standby=1 Suspend=2 Off=3 >>>> value: 0 >>>> 5 link-status: >>>> flags: enum >>>> enums: Good=0 Bad=1 >>>> value: 0 >>>> 6 non-desktop: >>>> flags: immutable range >>>> values: 0 1 >>>> value: 0 >>>> 4 TILE: >>>> flags: immutable blob >>>> blobs: >>>> >>>> value: >>>> 71 0 disconnected HDMI-A-1 0x0 0 >>>> 70 >>>> props: >>>> 1 EDID: >>>> flags: immutable blob >>>> blobs: >>>> >>>> value: >>>> 2 DPMS: >>>> flags: enum >>>> enums: On=0 Standby=1 Suspend=2 Off=3 >>>> value: 0 >>>> 5 link-status: >>>> flags: enum >>>> enums: Good=0 Bad=1 >>>> value: 0 >>>> 6 non-desktop: >>>> flags: immutable range >>>> values: 0 1 >>>> value: 0 >>>> 4 TILE: >>>> flags: immutable blob >>>> blobs: >>>> >>>> value: >>>> >>>> >>>> I will investigate details later this week. >>>> >>> >>> Could you please provide the related DTS file for the test? I will >>> also try to find out the reason for this unexpected issue. ;-) >> >> Unfortunately I didn't find enough time to debug this further. The above >> log is from Samsung Snow Chromebook, >> arch/arm/boot/dts/samsung/exynos5250-snow.dts >> >> > > I compare the differences in the following display path before and > after this patch series: > > exynos_dp -> nxp-ptn3460 -> panel "auo,b116xw03" > > The issue is likely caused by the &drm_connector_funcs.detect() > related logic. Before this patch series, the nxp-ptn3460 connector is > always connector_status_connected because there is not available > &drm_connector_funcs.detect(). After it, the DRM_BRIDGE_OP_DETECT flag > make the connection status depend on analogix_dp_bridge_detect(). > > Could you please add the following patches additionally and try again? > (Not the final solution, just validation) > > diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > index a93ff8f0a468..355911c47354 100644 > --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > @@ -1491,9 +1491,11 @@ int analogix_dp_bind(struct analogix_dp_device > *dp, struct drm_device *drm_dev) > } > } > > - bridge->ops = DRM_BRIDGE_OP_DETECT | > - DRM_BRIDGE_OP_EDID | > + bridge->ops = DRM_BRIDGE_OP_EDID | > DRM_BRIDGE_OP_MODES; > + if (drm_bridge_is_panel(dp->plat_data->next_bridge)) > + bridge->ops |= DRM_BRIDGE_OP_DETECT; > + > bridge->of_node = dp->dev->of_node; > bridge->type = DRM_MODE_CONNECTOR_eDP; > ret = devm_drm_bridge_add(dp->dev, &dp->bridge); It is better. Now the display panel is detected and reported to userspace, but it looks that something is not properly initialized, because there is garbage instead of the proper picture. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
Hi Marek,
On 9/1/2025 6:25 PM, Marek Szyprowski wrote:
> On 01.09.2025 05:41, Damon Ding wrote:
>> On 8/29/2025 4:23 PM, Marek Szyprowski wrote:
>>> On 29.08.2025 10:08, Damon Ding wrote:
>>>> On 8/20/2025 5:20 AM, Marek Szyprowski wrote:
>>>>> On 15.08.2025 04:59, Damon Ding wrote:
>>>>>> On 2025/8/15 5:16, Marek Szyprowski wrote:
>>>>>>> On 14.08.2025 16:33, Marek Szyprowski wrote:
>>>>>>>> On 14.08.2025 12:47, Damon Ding wrote:
>>>>>>>>> PATCH 1 is a small format optimization for struct
>>>>>>>>> analogid_dp_device.
>>>>>>>>> PATCH 2 is to perform mode setting in
>>>>>>>>> &drm_bridge_funcs.atomic_enable.
>>>>>>>>> PATCH 3-6 are preparations for apply drm_bridge_connector helper.
>>>>>>>>> PATCH 7 is to apply the drm_bridge_connector helper.
>>>>>>>>> PATCH 8-10 are to move the panel/bridge parsing to the Analogix
>>>>>>>>> side.
>>>>>>>>> PATCH 11-12 are preparations for apply panel_bridge helper.
>>>>>>>>> PATCH 13 is to apply the panel_bridge helper.
>>>>>>>>
>>>>>>>> This series lacks 'select DRM_BRIDGE_CONNECTOR' in ExynosDP's
>>>>>>>> Kconfig,
>>>>>>>> so it causes build break:
>>>>>>>>
>>>>>>>> drivers/gpu/drm/exynos/exynos_dp.c:177: undefined reference to
>>>>>>>> `drm_bridge_connector_init'
>>>>>>>> make[2]: *** [scripts/Makefile.vmlinux:91: vmlinux] Error 1
>>>>>>>>
>>>>>>>> After adding this dependency, the Exynos DP driver stops
>>>>>>>> working. On
>>>>>>>> Samsung Snow Chromebook I observed following issue:
>>>>>>>>
>>>>>>>> [ 4.534220] exynos-dp 145b0000.dp-controller: failed to attach
>>>>>>>> following panel or bridge (-16)
>>>>>>>> [ 4.543428] exynos-drm exynos-drm: failed to bind
>>>>>>>> 145b0000.dp-controller (ops exynos_dp_ops): -16
>>>>>>>> [ 4.551775] exynos-drm exynos-drm: adev bind failed: -16
>>>>>>>> [ 4.556559] exynos-dp 145b0000.dp-controller: probe with driver
>>>>>>>> exynos-dp failed with error -16
>>>>>>>>
>>>>>>>> I will investigate details later in the evening.
>>>>>>>
>>>>>>> The failure is caused by trying to add plat_data->next_bridge twice
>>>>>>> (from exynos_dp's .attach callback, and from analogix' ->bind
>>>>>>> callback).
>>>>>>>
>>>>>>>
>>>>>>> Best regards
>>>>>>
>>>>>> I see. The bridge attachment for the next bridge was not well thought
>>>>>> out. It may be better to move panel_bridge addition a little forward
>>>>>> and remove next_bridge attachment on the Analogix side. Then, the
>>>>>> Rockchip side and Exynos side can do their own next_bridge attachment
>>>>>> in &analogix_dp_plat_data.attach() as they want.
>>>>>>
>>>>>> Could you please help test the following modifications(they have been
>>>>>> tested on my RK3588S EVB1 Board) on the Samsung Snow Chromebook? ;-)
>>>>>
>>>>> Assuming that I properly applied the malformed diff, it doesn't solve
>>>>> all the issues. There are no errors reported though, but the display
>>>>> chain doesn't work and no valid mode is reported:
>>>>>
>>>>> # dmesg | grep drm
>>>>> [ 3.384992] [drm] Initialized panfrost 1.4.0 for 11800000.gpu on
>>>>> minor 0
>>>>> [ 4.487739] [drm] Exynos DRM: using 14400000.fimd device for DMA
>>>>> mapping operations
>>>>> [ 4.494202] exynos-drm exynos-drm: bound 14400000.fimd (ops
>>>>> fimd_component_ops)
>>>>> [ 4.502374] exynos-drm exynos-drm: bound 14450000.mixer (ops
>>>>> mixer_component_ops)
>>>>> [ 4.511930] exynos-drm exynos-drm: bound 145b0000.dp-controller
>>>>> (ops
>>>>> exynos_dp_ops)
>>>>> [ 4.518411] exynos-drm exynos-drm: bound 14530000.hdmi (ops
>>>>> hdmi_component_ops)
>>>>> [ 4.529628] [drm] Initialized exynos 1.1.0 for exynos-drm on
>>>>> minor 1
>>>>> [ 4.657434] exynos-drm exynos-drm: [drm] Cannot find any crtc or
>>>>> sizes
>>>>> [ 4.925023] exynos-drm exynos-drm: [drm] Cannot find any crtc or
>>>>> sizes
>>>>>
>>>>> # ./modetest -c -Mexynos
>>>>> Connectors:
>>>>> id encoder status name size (mm) modes
>>>>> encoders
>>>>> 69 0 disconnected LVDS-1 0x0 0
>>>>> 68
>>>>> props:
>>>>> 1 EDID:
>>>>> flags: immutable blob
>>>>> blobs:
>>>>>
>>>>> value:
>>>>> 2 DPMS:
>>>>> flags: enum
>>>>> enums: On=0 Standby=1 Suspend=2 Off=3
>>>>> value: 0
>>>>> 5 link-status:
>>>>> flags: enum
>>>>> enums: Good=0 Bad=1
>>>>> value: 0
>>>>> 6 non-desktop:
>>>>> flags: immutable range
>>>>> values: 0 1
>>>>> value: 0
>>>>> 4 TILE:
>>>>> flags: immutable blob
>>>>> blobs:
>>>>>
>>>>> value:
>>>>> 71 0 disconnected HDMI-A-1 0x0 0
>>>>> 70
>>>>> props:
>>>>> 1 EDID:
>>>>> flags: immutable blob
>>>>> blobs:
>>>>>
>>>>> value:
>>>>> 2 DPMS:
>>>>> flags: enum
>>>>> enums: On=0 Standby=1 Suspend=2 Off=3
>>>>> value: 0
>>>>> 5 link-status:
>>>>> flags: enum
>>>>> enums: Good=0 Bad=1
>>>>> value: 0
>>>>> 6 non-desktop:
>>>>> flags: immutable range
>>>>> values: 0 1
>>>>> value: 0
>>>>> 4 TILE:
>>>>> flags: immutable blob
>>>>> blobs:
>>>>>
>>>>> value:
>>>>>
>>>>>
>>>>> I will investigate details later this week.
>>>>>
>>>>
>>>> Could you please provide the related DTS file for the test? I will
>>>> also try to find out the reason for this unexpected issue. ;-)
>>>
>>> Unfortunately I didn't find enough time to debug this further. The above
>>> log is from Samsung Snow Chromebook,
>>> arch/arm/boot/dts/samsung/exynos5250-snow.dts
>>>
>>>
>>
>> I compare the differences in the following display path before and
>> after this patch series:
>>
>> exynos_dp -> nxp-ptn3460 -> panel "auo,b116xw03"
>>
>> The issue is likely caused by the &drm_connector_funcs.detect()
>> related logic. Before this patch series, the nxp-ptn3460 connector is
>> always connector_status_connected because there is not available
>> &drm_connector_funcs.detect(). After it, the DRM_BRIDGE_OP_DETECT flag
>> make the connection status depend on analogix_dp_bridge_detect().
>>
>> Could you please add the following patches additionally and try again?
>> (Not the final solution, just validation)
>>
>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> index a93ff8f0a468..355911c47354 100644
>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> @@ -1491,9 +1491,11 @@ int analogix_dp_bind(struct analogix_dp_device
>> *dp, struct drm_device *drm_dev)
>> }
>> }
>>
>> - bridge->ops = DRM_BRIDGE_OP_DETECT |
>> - DRM_BRIDGE_OP_EDID |
>> + bridge->ops = DRM_BRIDGE_OP_EDID |
>> DRM_BRIDGE_OP_MODES;
>> + if (drm_bridge_is_panel(dp->plat_data->next_bridge))
>> + bridge->ops |= DRM_BRIDGE_OP_DETECT;
>> +
>> bridge->of_node = dp->dev->of_node;
>> bridge->type = DRM_MODE_CONNECTOR_eDP;
>> ret = devm_drm_bridge_add(dp->dev, &dp->bridge);
>
> It is better. Now the display panel is detected and reported to
> userspace, but it looks that something is not properly initialized,
> because there is garbage instead of the proper picture.
>
I simulated the display path mentioned above on my RK3588S EVB1 Board.
To my slight surprise, it displayed normally with the reported connector
type DRM_MODE_CONNECTOR_LVDS. ;-)
The modifications included:
1.Synchronized the Analogix DP ralated DT configurations with Samsung
Snow Chromebook.
2.Skipped the I2C transfers and GPIO operations in nxp-ptn3460 driver.
3.Set the EDID to that of eDP Panel LP079QX1-SP0V forcibly.
Additionally, I added debug logs to verify whether the functions in
ptn3460_bridge_funcs were actually called.
Did you encounter any unexpected logs during your investigation? I'd
like to perform additional tests on this issue. :-)
Best regards,
Damon
diff --git a/arch/arm64/boot/dts/rockchip/rk3588s-evb1-v10.dts b/arch/arm64/boot/dts/rockchip/rk3588s-evb1-v10.dts
index 0df3e80f2dd9..51ce63fce6ee 100644
--- a/arch/arm64/boot/dts/rockchip/rk3588s-evb1-v10.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3588s-evb1-v10.dts
@@ -26,6 +26,18 @@ chosen {
stdout-path = "serial2:1500000n8";
};
+ panel: panel {
+ compatible = "auo,b116xw03";
+ power-supply = <&vcc3v3_lcd_edp>;
+ backlight = <&backlight>;
+
+ port {
+ panel_in: endpoint {
+ remote-endpoint = <&bridge_out>;
+ };
+ };
+ };
+
adc-keys {
compatible = "adc-keys";
io-channels = <&saradc 1>;
@@ -242,21 +254,6 @@ &combphy2_psu {
&edp0 {
force-hpd;
status = "okay";
-
- aux-bus {
- panel {
- compatible = "edp-panel";
- backlight = <&backlight>;
- power-supply = <&vcc3v3_lcd_edp>;
- no-hpd;
-
- port {
- panel_in_edp: endpoint {
- remote-endpoint = <&edp_out_panel>;
- };
- };
- };
- };
};
&edp0_in {
@@ -266,8 +263,8 @@ edp0_in_vp2: endpoint {
};
&edp0_out {
- edp_out_panel: endpoint {
- remote-endpoint = <&panel_in_edp>;
+ dp_out: endpoint {
+ remote-endpoint = <&bridge_in>;
};
};
@@ -290,6 +287,33 @@ es8388: audio-codec@11 {
PVDD-supply = <&vcc_3v3_s0>;
#sound-dai-cells = <0>;
};
+
+ ptn3460: lvds-bridge@20 {
+ compatible = "nxp,ptn3460";
+ reg = <0x20>;
+ edid-emulation = <5>;
+
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ port@0 {
+ reg = <0>;
+
+ bridge_out: endpoint {
+ remote-endpoint = <&panel_in>;
+ };
+ };
+
+ port@1 {
+ reg = <1>;
+
+ bridge_in: endpoint {
+ remote-endpoint = <&dp_out>;
+ };
+ };
+ };
+ };
};
&i2c8 {
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index a93ff8f0a468..355911c47354 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -1491,9 +1491,11 @@ int analogix_dp_bind(struct analogix_dp_device *dp, struct drm_device *drm_dev)
}
}
- bridge->ops = DRM_BRIDGE_OP_DETECT |
- DRM_BRIDGE_OP_EDID |
+ bridge->ops = DRM_BRIDGE_OP_EDID |
DRM_BRIDGE_OP_MODES;
+ if (drm_bridge_is_panel(dp->plat_data->next_bridge))
+ bridge->ops |= DRM_BRIDGE_OP_DETECT;
+
bridge->of_node = dp->dev->of_node;
bridge->type = DRM_MODE_CONNECTOR_eDP;
ret = devm_drm_bridge_add(dp->dev, &dp->bridge);
diff --git a/drivers/gpu/drm/bridge/nxp-ptn3460.c b/drivers/gpu/drm/bridge/nxp-ptn3460.c
index 7acb11f16dc1..cafbdcda2d29 100644
--- a/drivers/gpu/drm/bridge/nxp-ptn3460.c
+++ b/drivers/gpu/drm/bridge/nxp-ptn3460.c
@@ -52,6 +52,7 @@ static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr,
{
int ret;
+ return 0;
ret = i2c_master_send(ptn_bridge->client, &addr, 1);
if (ret < 0) {
DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
@@ -90,6 +91,7 @@ static int ptn3460_select_edid(struct ptn3460_bridge *ptn_bridge)
int ret;
char val;
+ return 0;
/* Load the selected edid into SRAM (accessed at PTN3460_EDID_ADDR) */
ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_SRAM_LOAD_ADDR,
ptn_bridge->edid_emulation);
@@ -152,6 +154,21 @@ static void ptn3460_disable(struct drm_bridge *bridge)
gpiod_set_value(ptn_bridge->gpio_pd_n, 0);
}
+static const u8 edid_data[] = {
+ 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x16, 0x83,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x17, 0x01, 0x00,
+ 0xA5, 0x10, 0x0C, 0x78, 0x06, 0xEF, 0x05, 0xA3, 0x54, 0x4C,
+ 0x99, 0x26, 0x0F, 0x50, 0x54, 0x00, 0x00, 0x00, 0x01, 0x01,
+ 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+ 0x01, 0x01, 0x01, 0x01, 0xEA, 0x4E, 0x00, 0x4C, 0x60, 0x00,
+ 0x14, 0x80, 0x0C, 0x10, 0x84, 0x00, 0x78, 0xA0, 0x00, 0x00,
+ 0x00, 0x18, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0xFE, 0x00, 0x4C, 0x50, 0x30, 0x37, 0x39,
+ 0x51, 0x58, 0x31, 0x2D, 0x53, 0x50, 0x30, 0x56, 0x00, 0x00,
+ 0x00, 0xFC, 0x00, 0x43, 0x6F, 0x6C, 0x6F, 0x72, 0x20, 0x4C,
+ 0x43, 0x44, 0x0A, 0x20, 0x20, 0x20, 0x00, 0x3F
+};
static const struct drm_edid *ptn3460_edid_read(struct drm_bridge *bridge,
struct drm_connector *connector)
@@ -178,7 +195,8 @@ static const struct drm_edid *ptn3460_edid_read(struct drm_bridge *bridge,
goto out;
}
- drm_edid = drm_edid_alloc(edid, EDID_LENGTH);
+ kfree(edid);
+ drm_edid = drm_edid_alloc(edid_data, EDID_LENGTH);
out:
if (power_off)
@@ -273,7 +291,7 @@ static int ptn3460_probe(struct i2c_client *client)
ptn_bridge->panel_bridge = panel_bridge;
ptn_bridge->client = client;
- ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown",
+ ptn_bridge->gpio_pd_n = devm_gpiod_get_optional(&client->dev, "powerdown",
GPIOD_OUT_HIGH);
if (IS_ERR(ptn_bridge->gpio_pd_n)) {
ret = PTR_ERR(ptn_bridge->gpio_pd_n);
@@ -285,7 +303,7 @@ static int ptn3460_probe(struct i2c_client *client)
* Request the reset pin low to avoid the bridge being
* initialized prematurely
*/
- ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset",
+ ptn_bridge->gpio_rst_n = devm_gpiod_get_optional(&client->dev, "reset",
GPIOD_OUT_LOW);
if (IS_ERR(ptn_bridge->gpio_rst_n)) {
ret = PTR_ERR(ptn_bridge->gpio_rst_n);
diff --git a/drivers/gpu/drm/exynos/exynos_dp.c b/drivers/gpu/drm/exynos/exynos_dp.c
index 80ba700d2964..d0422f940249 100644
--- a/drivers/gpu/drm/exynos/exynos_dp.c
+++ b/drivers/gpu/drm/exynos/exynos_dp.c
@@ -104,7 +104,7 @@ static int exynos_dp_bridge_attach(struct analogix_dp_plat_data *plat_data,
/* Pre-empt DP connector creation if there's a bridge */
if (plat_data->next_bridge) {
ret = drm_bridge_attach(&dp->encoder, plat_data->next_bridge, bridge,
- 0);
+ DRM_BRIDGE_ATTACH_NO_CONNECTOR);
if (ret)
return ret;
}
On 04.09.2025 05:19, Damon Ding wrote: > On 9/1/2025 6:25 PM, Marek Szyprowski wrote: >> On 01.09.2025 05:41, Damon Ding wrote: >>> On 8/29/2025 4:23 PM, Marek Szyprowski wrote: >>>> On 29.08.2025 10:08, Damon Ding wrote: >>>>> On 8/20/2025 5:20 AM, Marek Szyprowski wrote: >>>>>> On 15.08.2025 04:59, Damon Ding wrote: >>>>>>> On 2025/8/15 5:16, Marek Szyprowski wrote: >>>>>>>> On 14.08.2025 16:33, Marek Szyprowski wrote: >>>>>>>>> On 14.08.2025 12:47, Damon Ding wrote: >>>>>>>>>> PATCH 1 is a small format optimization for struct >>>>>>>>>> analogid_dp_device. >>>>>>>>>> PATCH 2 is to perform mode setting in >>>>>>>>>> &drm_bridge_funcs.atomic_enable. >>>>>>>>>> PATCH 3-6 are preparations for apply drm_bridge_connector >>>>>>>>>> helper. >>>>>>>>>> PATCH 7 is to apply the drm_bridge_connector helper. >>>>>>>>>> PATCH 8-10 are to move the panel/bridge parsing to the Analogix >>>>>>>>>> side. >>>>>>>>>> PATCH 11-12 are preparations for apply panel_bridge helper. >>>>>>>>>> PATCH 13 is to apply the panel_bridge helper. >>>>>>>>> ... >>>>>> >>>>> >>>>> Could you please provide the related DTS file for the test? I will >>>>> also try to find out the reason for this unexpected issue. ;-) >>>> >>>> Unfortunately I didn't find enough time to debug this further. The >>>> above >>>> log is from Samsung Snow Chromebook, >>>> arch/arm/boot/dts/samsung/exynos5250-snow.dts >>>> >>>> >>> >>> I compare the differences in the following display path before and >>> after this patch series: >>> >>> exynos_dp -> nxp-ptn3460 -> panel "auo,b116xw03" >>> >>> The issue is likely caused by the &drm_connector_funcs.detect() >>> related logic. Before this patch series, the nxp-ptn3460 connector is >>> always connector_status_connected because there is not available >>> &drm_connector_funcs.detect(). After it, the DRM_BRIDGE_OP_DETECT flag >>> make the connection status depend on analogix_dp_bridge_detect(). >>> >>> Could you please add the following patches additionally and try again? >>> (Not the final solution, just validation) >>> >>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c >>> b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c >>> index a93ff8f0a468..355911c47354 100644 >>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c >>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c >>> @@ -1491,9 +1491,11 @@ int analogix_dp_bind(struct analogix_dp_device >>> *dp, struct drm_device *drm_dev) >>> } >>> } >>> >>> - bridge->ops = DRM_BRIDGE_OP_DETECT | >>> - DRM_BRIDGE_OP_EDID | >>> + bridge->ops = DRM_BRIDGE_OP_EDID | >>> DRM_BRIDGE_OP_MODES; >>> + if (drm_bridge_is_panel(dp->plat_data->next_bridge)) >>> + bridge->ops |= DRM_BRIDGE_OP_DETECT; >>> + >>> bridge->of_node = dp->dev->of_node; >>> bridge->type = DRM_MODE_CONNECTOR_eDP; >>> ret = devm_drm_bridge_add(dp->dev, &dp->bridge); >> >> It is better. Now the display panel is detected and reported to >> userspace, but it looks that something is not properly initialized, >> because there is garbage instead of the proper picture. >> > > I simulated the display path mentioned above on my RK3588S EVB1 Board. > To my slight surprise, it displayed normally with the reported > connector type DRM_MODE_CONNECTOR_LVDS. ;-) > > The modifications included: > 1.Synchronized the Analogix DP ralated DT configurations with Samsung > Snow Chromebook. > 2.Skipped the I2C transfers and GPIO operations in nxp-ptn3460 driver. > 3.Set the EDID to that of eDP Panel LP079QX1-SP0V forcibly. > > Additionally, I added debug logs to verify whether the functions in > ptn3460_bridge_funcs were actually called. > > Did you encounter any unexpected logs during your investigation? I'd > like to perform additional tests on this issue. :-) Okay, I've finally went to the office and tested manually all 3 Chromebook boards witch use exynos-dp based display hardware. Previously I only did the remote tests and observed result on a webcam, which was not directed directly at the tested displays, so I only saw the glare from the display panel. The results are as follows: 1. Snow (arch/arm/boot/dts/samsung/exynos5250-snow.dts) - exynos-dp -> nxp-ptn3460 1366x768 lvds panel - works fine with the above mentioned change. 2. Peach-Pit (arch/arm/boot/dts/samsung/exynos5420-peach-pit.dts) - exynos-dp -> parade,ps8625 -> auo,b116xw03 1366x768 lvds panel - displays garbage, this was the only board I previously was able to see partially on the webcam. 3. Peach-Pi (arch/arm/boot/dts/samsung/exynos5800-peach-pi.dts) - exynos-dp -> auo,b133htn01 1920x1080 edp panel - also displays garbage. Then I found why both Peach boards displays garbage on boot - the framebuffer emulation is initialized for 1024x786 resolution, which is not handled by those panels. This is a bit strange, because the connector implemented by the panel reports proper native mode to drm and userspace. 'modetest -c' shows the right resolution. Also when I run 'modetest -s' with the panel's native resolution then the test pattern is correctly displayed on all three boards. Then I've played a bit with the analogix code and it looks that this 1024x768 mode is some kind default mode which comes from analogix_dp_bridge_edid_read() function, which has been introduced by this patchset. When I removed DRM_BRIDGE_OP_EDID flag from bridge->ops, then I got it finally working again properly on all three boards. I hope this helps fixing this issue. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
Hi Marek, On 9/4/2025 9:27 PM, Marek Szyprowski wrote: > On 04.09.2025 05:19, Damon Ding wrote: >> On 9/1/2025 6:25 PM, Marek Szyprowski wrote: >>> On 01.09.2025 05:41, Damon Ding wrote: >>>> On 8/29/2025 4:23 PM, Marek Szyprowski wrote: >>>>> On 29.08.2025 10:08, Damon Ding wrote: >>>>>> On 8/20/2025 5:20 AM, Marek Szyprowski wrote: >>>>>>> On 15.08.2025 04:59, Damon Ding wrote: >>>>>>>> On 2025/8/15 5:16, Marek Szyprowski wrote: >>>>>>>>> On 14.08.2025 16:33, Marek Szyprowski wrote: >>>>>>>>>> On 14.08.2025 12:47, Damon Ding wrote: >>>>>>>>>>> PATCH 1 is a small format optimization for struct >>>>>>>>>>> analogid_dp_device. >>>>>>>>>>> PATCH 2 is to perform mode setting in >>>>>>>>>>> &drm_bridge_funcs.atomic_enable. >>>>>>>>>>> PATCH 3-6 are preparations for apply drm_bridge_connector >>>>>>>>>>> helper. >>>>>>>>>>> PATCH 7 is to apply the drm_bridge_connector helper. >>>>>>>>>>> PATCH 8-10 are to move the panel/bridge parsing to the Analogix >>>>>>>>>>> side. >>>>>>>>>>> PATCH 11-12 are preparations for apply panel_bridge helper. >>>>>>>>>>> PATCH 13 is to apply the panel_bridge helper. >>>>>>>>>> ... >>>>>>> >>>>>> >>>>>> Could you please provide the related DTS file for the test? I will >>>>>> also try to find out the reason for this unexpected issue. ;-) >>>>> >>>>> Unfortunately I didn't find enough time to debug this further. The >>>>> above >>>>> log is from Samsung Snow Chromebook, >>>>> arch/arm/boot/dts/samsung/exynos5250-snow.dts >>>>> >>>>> >>>> >>>> I compare the differences in the following display path before and >>>> after this patch series: >>>> >>>> exynos_dp -> nxp-ptn3460 -> panel "auo,b116xw03" >>>> >>>> The issue is likely caused by the &drm_connector_funcs.detect() >>>> related logic. Before this patch series, the nxp-ptn3460 connector is >>>> always connector_status_connected because there is not available >>>> &drm_connector_funcs.detect(). After it, the DRM_BRIDGE_OP_DETECT flag >>>> make the connection status depend on analogix_dp_bridge_detect(). >>>> >>>> Could you please add the following patches additionally and try again? >>>> (Not the final solution, just validation) >>>> >>>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c >>>> b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c >>>> index a93ff8f0a468..355911c47354 100644 >>>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c >>>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c >>>> @@ -1491,9 +1491,11 @@ int analogix_dp_bind(struct analogix_dp_device >>>> *dp, struct drm_device *drm_dev) >>>> } >>>> } >>>> >>>> - bridge->ops = DRM_BRIDGE_OP_DETECT | >>>> - DRM_BRIDGE_OP_EDID | >>>> + bridge->ops = DRM_BRIDGE_OP_EDID | >>>> DRM_BRIDGE_OP_MODES; >>>> + if (drm_bridge_is_panel(dp->plat_data->next_bridge)) >>>> + bridge->ops |= DRM_BRIDGE_OP_DETECT; >>>> + >>>> bridge->of_node = dp->dev->of_node; >>>> bridge->type = DRM_MODE_CONNECTOR_eDP; >>>> ret = devm_drm_bridge_add(dp->dev, &dp->bridge); >>> >>> It is better. Now the display panel is detected and reported to >>> userspace, but it looks that something is not properly initialized, >>> because there is garbage instead of the proper picture. >>> >> >> I simulated the display path mentioned above on my RK3588S EVB1 Board. >> To my slight surprise, it displayed normally with the reported >> connector type DRM_MODE_CONNECTOR_LVDS. ;-) >> >> The modifications included: >> 1.Synchronized the Analogix DP ralated DT configurations with Samsung >> Snow Chromebook. >> 2.Skipped the I2C transfers and GPIO operations in nxp-ptn3460 driver. >> 3.Set the EDID to that of eDP Panel LP079QX1-SP0V forcibly. >> >> Additionally, I added debug logs to verify whether the functions in >> ptn3460_bridge_funcs were actually called. >> >> Did you encounter any unexpected logs during your investigation? I'd >> like to perform additional tests on this issue. :-) > > > Okay, I've finally went to the office and tested manually all 3 > Chromebook boards witch use exynos-dp based display hardware. Previously > I only did the remote tests and observed result on a webcam, which was > not directed directly at the tested displays, so I only saw the glare > from the display panel. > > The results are as follows: > > 1. Snow (arch/arm/boot/dts/samsung/exynos5250-snow.dts) - exynos-dp -> > nxp-ptn3460 1366x768 lvds panel - works fine with the above mentioned > change. > > 2. Peach-Pit (arch/arm/boot/dts/samsung/exynos5420-peach-pit.dts) - > exynos-dp -> parade,ps8625 -> auo,b116xw03 1366x768 lvds panel - > displays garbage, this was the only board I previously was able to see > partially on the webcam. > > 3. Peach-Pi (arch/arm/boot/dts/samsung/exynos5800-peach-pi.dts) - > exynos-dp -> auo,b133htn01 1920x1080 edp panel - also displays garbage. > > Then I found why both Peach boards displays garbage on boot - the > framebuffer emulation is initialized for 1024x786 resolution, which is > not handled by those panels. This is a bit strange, because the > connector implemented by the panel reports proper native mode to drm and > userspace. 'modetest -c' shows the right resolution. Also when I run > 'modetest -s' with the panel's native resolution then the test pattern > is correctly displayed on all three boards. > > > Then I've played a bit with the analogix code and it looks that this > 1024x768 mode is some kind default mode which comes from > analogix_dp_bridge_edid_read() function, which has been introduced by > this patchset. When I removed DRM_BRIDGE_OP_EDID flag from bridge->ops, > then I got it finally working again properly on all three boards. I hope > this helps fixing this issue. > Thank you for your help with the investigation. :-) Based on your helpful findings and Dmitry's earlier suggestions[0], it is better to distinguish the &drm_bridge->ops of Analogix bridge based on whether the downstream device is a panel, a bridge or neither. 1. If there is a panel after, the &drm_bridge->ops should be set to DRM_BRIDGE_OP_MODES | DRM_BRIDGE_OP_DETECT. Since the &drm_bridge->ops of panel_bridge is DRM_BRIDGE_OP_MODES and the panel-edp driver reads EDID in &drm_panel_funcs.get_modes(), the DRM_BRIDGE_OP_EDID should be removed to ensure proper invocation for the &drm_bridge_funcs.get_modes() of panel_bridge. 2. If there is a bridge after, the &drm_bridge->ops should be set to NULL. The OP_EDID and OP_MODES supports depends on the next bridge rather than the Analogix bridge. According to your investigation, nxp-ptn3460 supports &drm_bridge_funcs.edid_read() while parade-ps8625 do not. Additionally, since some bridges does not support &drm_bridge_funcs.detect(), which regards as connector_status_connected by default according to drm_helper_probe_detect()(drivers/gpu/drm_probe_helper.c), the connection status should also depends on the next bridge rather than the Analogix bridge. 3. If there is neither a panel nor a bridge, the &drm_bridge->ops should be set to DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_DETECT. In this case, the Analogix DP driver may work in the DP mode, so the OP_EDID and OP_DETECT supports should be helpful. Best regards, Damon [0]https://lore.kernel.org/all/incxmqneeurgli5h6p3hn3bgztxrzyk5eq2h5nq4lgzalohslq@mvehvr4cgyim/
© 2016 - 2025 Red Hat, Inc.