drivers/gpu/drm/mediatek/mtk_dsi.c | 167 +++++++++++++++-------------- 1 file changed, 84 insertions(+), 83 deletions(-)
DRM bridge drivers are now attaching their DSI device at probe time,
which requires us to register our DSI host in order to let the bridge
to probe: this recently started producing an endless -EPROBE_DEFER
loop on some machines that are using external bridges, like the
parade-ps8640, found on the ACER Chromebook R13.
Now that the DSI hosts/devices probe sequence is documented, we can
do adjustments to the mtk_dsi driver as to both fix now and make sure
to avoid this situation in the future: for this, following what is
documented in drm_bridge.c, move the mtk_dsi component_add() to the
mtk_dsi_ops.attach callback and delete it in the detach callback;
keeping in mind that we are registering a drm_bridge for our DSI,
which is only used/attached if the DSI Host is bound, it wouldn't
make sense to keep adding our bridge at probe time (as it would
be useless to have it if mtk_dsi_ops.attach() fails!), so also move
that one to the dsi host attach function (and remove it in detach).
Cc: <stable@vger.kernel.org> # 5.15.x
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
---
drivers/gpu/drm/mediatek/mtk_dsi.c | 167 +++++++++++++++--------------
1 file changed, 84 insertions(+), 83 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 5d90d2eb0019..bced4c7d668e 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -786,18 +786,101 @@ void mtk_dsi_ddp_stop(struct device *dev)
mtk_dsi_poweroff(dsi);
}
+static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
+{
+ int ret;
+
+ ret = drm_simple_encoder_init(drm, &dsi->encoder,
+ DRM_MODE_ENCODER_DSI);
+ if (ret) {
+ DRM_ERROR("Failed to encoder init to drm\n");
+ return ret;
+ }
+
+ dsi->encoder.possible_crtcs = mtk_drm_find_possible_crtc_by_comp(drm, dsi->host.dev);
+
+ ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL,
+ DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+ if (ret)
+ goto err_cleanup_encoder;
+
+ dsi->connector = drm_bridge_connector_init(drm, &dsi->encoder);
+ if (IS_ERR(dsi->connector)) {
+ DRM_ERROR("Unable to create bridge connector\n");
+ ret = PTR_ERR(dsi->connector);
+ goto err_cleanup_encoder;
+ }
+ drm_connector_attach_encoder(dsi->connector, &dsi->encoder);
+
+ return 0;
+
+err_cleanup_encoder:
+ drm_encoder_cleanup(&dsi->encoder);
+ return ret;
+}
+
+static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
+{
+ int ret;
+ struct drm_device *drm = data;
+ struct mtk_dsi *dsi = dev_get_drvdata(dev);
+
+ ret = mtk_dsi_encoder_init(drm, dsi);
+ if (ret)
+ return ret;
+
+ return device_reset_optional(dev);
+}
+
+static void mtk_dsi_unbind(struct device *dev, struct device *master,
+ void *data)
+{
+ struct mtk_dsi *dsi = dev_get_drvdata(dev);
+
+ drm_encoder_cleanup(&dsi->encoder);
+}
+
+static const struct component_ops mtk_dsi_component_ops = {
+ .bind = mtk_dsi_bind,
+ .unbind = mtk_dsi_unbind,
+};
+
static int mtk_dsi_host_attach(struct mipi_dsi_host *host,
struct mipi_dsi_device *device)
{
struct mtk_dsi *dsi = host_to_dsi(host);
+ struct device *dev = host->dev;
+ int ret;
dsi->lanes = device->lanes;
dsi->format = device->format;
dsi->mode_flags = device->mode_flags;
+ dsi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0);
+ if (IS_ERR(dsi->next_bridge))
+ return PTR_ERR(dsi->next_bridge);
+
+ drm_bridge_add(&dsi->bridge);
+
+ ret = component_add(host->dev, &mtk_dsi_component_ops);
+ if (ret) {
+ DRM_ERROR("failed to add dsi_host component: %d\n", ret);
+ drm_bridge_remove(&dsi->bridge);
+ return ret;
+ }
return 0;
}
+static int mtk_dsi_host_detach(struct mipi_dsi_host *host,
+ struct mipi_dsi_device *device)
+{
+ struct mtk_dsi *dsi = host_to_dsi(host);
+
+ component_del(host->dev, &mtk_dsi_component_ops);
+ drm_bridge_remove(&dsi->bridge);
+ return 0;
+}
+
static void mtk_dsi_wait_for_idle(struct mtk_dsi *dsi)
{
int ret;
@@ -938,73 +1021,14 @@ static ssize_t mtk_dsi_host_transfer(struct mipi_dsi_host *host,
static const struct mipi_dsi_host_ops mtk_dsi_ops = {
.attach = mtk_dsi_host_attach,
+ .detach = mtk_dsi_host_detach,
.transfer = mtk_dsi_host_transfer,
};
-static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
-{
- int ret;
-
- ret = drm_simple_encoder_init(drm, &dsi->encoder,
- DRM_MODE_ENCODER_DSI);
- if (ret) {
- DRM_ERROR("Failed to encoder init to drm\n");
- return ret;
- }
-
- dsi->encoder.possible_crtcs = mtk_drm_find_possible_crtc_by_comp(drm, dsi->host.dev);
-
- ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL,
- DRM_BRIDGE_ATTACH_NO_CONNECTOR);
- if (ret)
- goto err_cleanup_encoder;
-
- dsi->connector = drm_bridge_connector_init(drm, &dsi->encoder);
- if (IS_ERR(dsi->connector)) {
- DRM_ERROR("Unable to create bridge connector\n");
- ret = PTR_ERR(dsi->connector);
- goto err_cleanup_encoder;
- }
- drm_connector_attach_encoder(dsi->connector, &dsi->encoder);
-
- return 0;
-
-err_cleanup_encoder:
- drm_encoder_cleanup(&dsi->encoder);
- return ret;
-}
-
-static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
-{
- int ret;
- struct drm_device *drm = data;
- struct mtk_dsi *dsi = dev_get_drvdata(dev);
-
- ret = mtk_dsi_encoder_init(drm, dsi);
- if (ret)
- return ret;
-
- return device_reset_optional(dev);
-}
-
-static void mtk_dsi_unbind(struct device *dev, struct device *master,
- void *data)
-{
- struct mtk_dsi *dsi = dev_get_drvdata(dev);
-
- drm_encoder_cleanup(&dsi->encoder);
-}
-
-static const struct component_ops mtk_dsi_component_ops = {
- .bind = mtk_dsi_bind,
- .unbind = mtk_dsi_unbind,
-};
-
static int mtk_dsi_probe(struct platform_device *pdev)
{
struct mtk_dsi *dsi;
struct device *dev = &pdev->dev;
- struct drm_panel *panel;
struct resource *regs;
int irq_num;
int ret;
@@ -1021,19 +1045,6 @@ static int mtk_dsi_probe(struct platform_device *pdev)
return ret;
}
- ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
- &panel, &dsi->next_bridge);
- if (ret)
- goto err_unregister_host;
-
- if (panel) {
- dsi->next_bridge = devm_drm_panel_bridge_add(dev, panel);
- if (IS_ERR(dsi->next_bridge)) {
- ret = PTR_ERR(dsi->next_bridge);
- goto err_unregister_host;
- }
- }
-
dsi->driver_data = of_device_get_match_data(dev);
dsi->engine_clk = devm_clk_get(dev, "engine");
@@ -1098,14 +1109,6 @@ static int mtk_dsi_probe(struct platform_device *pdev)
dsi->bridge.of_node = dev->of_node;
dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
- drm_bridge_add(&dsi->bridge);
-
- ret = component_add(&pdev->dev, &mtk_dsi_component_ops);
- if (ret) {
- dev_err(&pdev->dev, "failed to add component: %d\n", ret);
- goto err_unregister_host;
- }
-
return 0;
err_unregister_host:
@@ -1118,8 +1121,6 @@ static int mtk_dsi_remove(struct platform_device *pdev)
struct mtk_dsi *dsi = platform_get_drvdata(pdev);
mtk_output_dsi_disable(dsi);
- drm_bridge_remove(&dsi->bridge);
- component_del(&pdev->dev, &mtk_dsi_component_ops);
mipi_dsi_host_unregister(&dsi->host);
return 0;
--
2.33.1
Hi, Angelo: On Mon, 2022-01-31 at 09:55 +0100, AngeloGioacchino Del Regno wrote: > DRM bridge drivers are now attaching their DSI device at probe time, > which requires us to register our DSI host in order to let the bridge > to probe: this recently started producing an endless -EPROBE_DEFER > loop on some machines that are using external bridges, like the > parade-ps8640, found on the ACER Chromebook R13. > > Now that the DSI hosts/devices probe sequence is documented, we can > do adjustments to the mtk_dsi driver as to both fix now and make sure > to avoid this situation in the future: for this, following what is > documented in drm_bridge.c, move the mtk_dsi component_add() to the > mtk_dsi_ops.attach callback and delete it in the detach callback; > keeping in mind that we are registering a drm_bridge for our DSI, > which is only used/attached if the DSI Host is bound, it wouldn't > make sense to keep adding our bridge at probe time (as it would > be useless to have it if mtk_dsi_ops.attach() fails!), so also move > that one to the dsi host attach function (and remove it in detach). > > Cc: <stable@vger.kernel.org> # 5.15.x > Signed-off-by: AngeloGioacchino Del Regno < > angelogioacchino.delregno@collabora.com> > Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com> > Reviewed-by: Jagan Teki <jagan@amarulasolutions.com> > > --- > drivers/gpu/drm/mediatek/mtk_dsi.c | 167 +++++++++++++++---------- > ---- > 1 file changed, 84 insertions(+), 83 deletions(-) > > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c > b/drivers/gpu/drm/mediatek/mtk_dsi.c > index 5d90d2eb0019..bced4c7d668e 100644 > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c > @@ -786,18 +786,101 @@ void mtk_dsi_ddp_stop(struct device *dev) > mtk_dsi_poweroff(dsi); > } > > [snip] > + > static int mtk_dsi_host_attach(struct mipi_dsi_host *host, > struct mipi_dsi_device *device) > { > struct mtk_dsi *dsi = host_to_dsi(host); > + struct device *dev = host->dev; > + int ret; > > dsi->lanes = device->lanes; > dsi->format = device->format; > dsi->mode_flags = device->mode_flags; > + dsi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, > 0); The original would process panel. Why do you remove the panel part? It's better that someone has a platform of DSI->Panel to test this patch. Regards, CK > + if (IS_ERR(dsi->next_bridge)) > + return PTR_ERR(dsi->next_bridge); > + > + drm_bridge_add(&dsi->bridge); > + > + ret = component_add(host->dev, &mtk_dsi_component_ops); > + if (ret) { > + DRM_ERROR("failed to add dsi_host component: %d\n", > ret); > + drm_bridge_remove(&dsi->bridge); > + return ret; > + } > > return 0; > } > > +static int mtk_dsi_host_detach(struct mipi_dsi_host *host, > + struct mipi_dsi_device *device) > +{ > + struct mtk_dsi *dsi = host_to_dsi(host); > + > + component_del(host->dev, &mtk_dsi_component_ops); > + drm_bridge_remove(&dsi->bridge); > + return 0; > +} > + > static void mtk_dsi_wait_for_idle(struct mtk_dsi *dsi) > { > int ret; > @@ -938,73 +1021,14 @@ static ssize_t mtk_dsi_host_transfer(struct > mipi_dsi_host *host, > > static const struct mipi_dsi_host_ops mtk_dsi_ops = { > .attach = mtk_dsi_host_attach, > + .detach = mtk_dsi_host_detach, > .transfer = mtk_dsi_host_transfer, > }; > > [snip] > - > static int mtk_dsi_probe(struct platform_device *pdev) > { > struct mtk_dsi *dsi; > struct device *dev = &pdev->dev; > - struct drm_panel *panel; > struct resource *regs; > int irq_num; > int ret; > @@ -1021,19 +1045,6 @@ static int mtk_dsi_probe(struct > platform_device *pdev) > return ret; > } > > - ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, > - &panel, &dsi->next_bridge); > - if (ret) > - goto err_unregister_host; > - > - if (panel) { > - dsi->next_bridge = devm_drm_panel_bridge_add(dev, > panel); > - if (IS_ERR(dsi->next_bridge)) { > - ret = PTR_ERR(dsi->next_bridge); > - goto err_unregister_host; > - } > - } > - > dsi->driver_data = of_device_get_match_data(dev); > > dsi->engine_clk = devm_clk_get(dev, "engine"); > @@ -1098,14 +1109,6 @@ static int mtk_dsi_probe(struct > platform_device *pdev) > dsi->bridge.of_node = dev->of_node; > dsi->bridge.type = DRM_MODE_CONNECTOR_DSI; > > - drm_bridge_add(&dsi->bridge); > - > - ret = component_add(&pdev->dev, &mtk_dsi_component_ops); > - if (ret) { > - dev_err(&pdev->dev, "failed to add component: %d\n", > ret); > - goto err_unregister_host; > - } > - > return 0; > > err_unregister_host: > @@ -1118,8 +1121,6 @@ static int mtk_dsi_remove(struct > platform_device *pdev) > struct mtk_dsi *dsi = platform_get_drvdata(pdev); > > mtk_output_dsi_disable(dsi); > - drm_bridge_remove(&dsi->bridge); > - component_del(&pdev->dev, &mtk_dsi_component_ops); > mipi_dsi_host_unregister(&dsi->host); > > return 0;
Hi, Angelo: On Tue, 2022-02-08 at 16:20 +0800, CK Hu wrote: > Hi, Angelo: > > On Mon, 2022-01-31 at 09:55 +0100, AngeloGioacchino Del Regno wrote: > > DRM bridge drivers are now attaching their DSI device at probe > > time, > > which requires us to register our DSI host in order to let the > > bridge > > to probe: this recently started producing an endless -EPROBE_DEFER > > loop on some machines that are using external bridges, like the > > parade-ps8640, found on the ACER Chromebook R13. > > > > Now that the DSI hosts/devices probe sequence is documented, we can > > do adjustments to the mtk_dsi driver as to both fix now and make > > sure > > to avoid this situation in the future: for this, following what is > > documented in drm_bridge.c, move the mtk_dsi component_add() to the > > mtk_dsi_ops.attach callback and delete it in the detach callback; > > keeping in mind that we are registering a drm_bridge for our DSI, > > which is only used/attached if the DSI Host is bound, it wouldn't > > make sense to keep adding our bridge at probe time (as it would > > be useless to have it if mtk_dsi_ops.attach() fails!), so also move > > that one to the dsi host attach function (and remove it in detach). > > > > Cc: <stable@vger.kernel.org> # 5.15.x > > Signed-off-by: AngeloGioacchino Del Regno < > > angelogioacchino.delregno@collabora.com> > > Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com> > > Reviewed-by: Jagan Teki <jagan@amarulasolutions.com> > > > > --- > > drivers/gpu/drm/mediatek/mtk_dsi.c | 167 +++++++++++++++---------- > > ---- > > 1 file changed, 84 insertions(+), 83 deletions(-) > > > > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c > > b/drivers/gpu/drm/mediatek/mtk_dsi.c > > index 5d90d2eb0019..bced4c7d668e 100644 > > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c > > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c > > @@ -786,18 +786,101 @@ void mtk_dsi_ddp_stop(struct device *dev) > > mtk_dsi_poweroff(dsi); > > } > > > > > > [snip] > > > + > > static int mtk_dsi_host_attach(struct mipi_dsi_host *host, > > struct mipi_dsi_device *device) > > { > > struct mtk_dsi *dsi = host_to_dsi(host); > > + struct device *dev = host->dev; > > + int ret; > > > > dsi->lanes = device->lanes; > > dsi->format = device->format; > > dsi->mode_flags = device->mode_flags; > > + dsi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, > > 0); > > The original would process panel. Why do you remove the panel part? > It's better that someone has a platform of DSI->Panel to test this > patch. Sorry, devm_drm_of_get_bridge() has processed the panel part, so for this patch, Reviewed-by: CK Hu <ck.hu@mediatek.com> > > Regards, > CK > > > + if (IS_ERR(dsi->next_bridge)) > > + return PTR_ERR(dsi->next_bridge); > > + > > + drm_bridge_add(&dsi->bridge); > > + > > + ret = component_add(host->dev, &mtk_dsi_component_ops); > > + if (ret) { > > + DRM_ERROR("failed to add dsi_host component: %d\n", > > ret); > > + drm_bridge_remove(&dsi->bridge); > > + return ret; > > + } > > > > return 0; > > } > > > > +static int mtk_dsi_host_detach(struct mipi_dsi_host *host, > > + struct mipi_dsi_device *device) > > +{ > > + struct mtk_dsi *dsi = host_to_dsi(host); > > + > > + component_del(host->dev, &mtk_dsi_component_ops); > > + drm_bridge_remove(&dsi->bridge); > > + return 0; > > +} > > + > > static void mtk_dsi_wait_for_idle(struct mtk_dsi *dsi) > > { > > int ret; > > @@ -938,73 +1021,14 @@ static ssize_t mtk_dsi_host_transfer(struct > > mipi_dsi_host *host, > > > > static const struct mipi_dsi_host_ops mtk_dsi_ops = { > > .attach = mtk_dsi_host_attach, > > + .detach = mtk_dsi_host_detach, > > .transfer = mtk_dsi_host_transfer, > > }; > > > > > > [snip] > > > - > > static int mtk_dsi_probe(struct platform_device *pdev) > > { > > struct mtk_dsi *dsi; > > struct device *dev = &pdev->dev; > > - struct drm_panel *panel; > > struct resource *regs; > > int irq_num; > > int ret; > > @@ -1021,19 +1045,6 @@ static int mtk_dsi_probe(struct > > platform_device *pdev) > > return ret; > > } > > > > - ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, > > - &panel, &dsi->next_bridge); > > - if (ret) > > - goto err_unregister_host; > > - > > - if (panel) { > > - dsi->next_bridge = devm_drm_panel_bridge_add(dev, > > panel); > > - if (IS_ERR(dsi->next_bridge)) { > > - ret = PTR_ERR(dsi->next_bridge); > > - goto err_unregister_host; > > - } > > - } > > - > > dsi->driver_data = of_device_get_match_data(dev); > > > > dsi->engine_clk = devm_clk_get(dev, "engine"); > > @@ -1098,14 +1109,6 @@ static int mtk_dsi_probe(struct > > platform_device *pdev) > > dsi->bridge.of_node = dev->of_node; > > dsi->bridge.type = DRM_MODE_CONNECTOR_DSI; > > > > - drm_bridge_add(&dsi->bridge); > > - > > - ret = component_add(&pdev->dev, &mtk_dsi_component_ops); > > - if (ret) { > > - dev_err(&pdev->dev, "failed to add component: %d\n", > > ret); > > - goto err_unregister_host; > > - } > > - > > return 0; > > > > err_unregister_host: > > @@ -1118,8 +1121,6 @@ static int mtk_dsi_remove(struct > > platform_device *pdev) > > struct mtk_dsi *dsi = platform_get_drvdata(pdev); > > > > mtk_output_dsi_disable(dsi); > > - drm_bridge_remove(&dsi->bridge); > > - component_del(&pdev->dev, &mtk_dsi_component_ops); > > mipi_dsi_host_unregister(&dsi->host); > > > > return 0;
Il 08/02/22 09:32, CK Hu ha scritto: > Hi, Angelo: > > On Tue, 2022-02-08 at 16:20 +0800, CK Hu wrote: >> Hi, Angelo: >> >> On Mon, 2022-01-31 at 09:55 +0100, AngeloGioacchino Del Regno wrote: >>> DRM bridge drivers are now attaching their DSI device at probe >>> time, >>> which requires us to register our DSI host in order to let the >>> bridge >>> to probe: this recently started producing an endless -EPROBE_DEFER >>> loop on some machines that are using external bridges, like the >>> parade-ps8640, found on the ACER Chromebook R13. >>> >>> Now that the DSI hosts/devices probe sequence is documented, we can >>> do adjustments to the mtk_dsi driver as to both fix now and make >>> sure >>> to avoid this situation in the future: for this, following what is >>> documented in drm_bridge.c, move the mtk_dsi component_add() to the >>> mtk_dsi_ops.attach callback and delete it in the detach callback; >>> keeping in mind that we are registering a drm_bridge for our DSI, >>> which is only used/attached if the DSI Host is bound, it wouldn't >>> make sense to keep adding our bridge at probe time (as it would >>> be useless to have it if mtk_dsi_ops.attach() fails!), so also move >>> that one to the dsi host attach function (and remove it in detach). >>> >>> Cc: <stable@vger.kernel.org> # 5.15.x >>> Signed-off-by: AngeloGioacchino Del Regno < >>> angelogioacchino.delregno@collabora.com> >>> Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com> >>> Reviewed-by: Jagan Teki <jagan@amarulasolutions.com> >>> >>> --- >>> drivers/gpu/drm/mediatek/mtk_dsi.c | 167 +++++++++++++++---------- >>> ---- >>> 1 file changed, 84 insertions(+), 83 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c >>> b/drivers/gpu/drm/mediatek/mtk_dsi.c >>> index 5d90d2eb0019..bced4c7d668e 100644 >>> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c >>> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c >>> @@ -786,18 +786,101 @@ void mtk_dsi_ddp_stop(struct device *dev) >>> mtk_dsi_poweroff(dsi); >>> } >>> >>> >> >> [snip] >> >>> + >>> static int mtk_dsi_host_attach(struct mipi_dsi_host *host, >>> struct mipi_dsi_device *device) >>> { >>> struct mtk_dsi *dsi = host_to_dsi(host); >>> + struct device *dev = host->dev; >>> + int ret; >>> >>> dsi->lanes = device->lanes; >>> dsi->format = device->format; >>> dsi->mode_flags = device->mode_flags; >>> + dsi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, >>> 0); >> >> The original would process panel. Why do you remove the panel part? >> It's better that someone has a platform of DSI->Panel to test this >> patch. > > Sorry, devm_drm_of_get_bridge() has processed the panel part, so for > this patch, > > Reviewed-by: CK Hu <ck.hu@mediatek.com> > No worries! Thanks for the review/approval. Regards, Angelo >> >> Regards, >> CK >>
Hi Angelo, On Mon, Jan 31, 2022 at 09:55:20AM +0100, AngeloGioacchino Del Regno wrote: > DRM bridge drivers are now attaching their DSI device at probe time, > which requires us to register our DSI host in order to let the bridge > to probe: this recently started producing an endless -EPROBE_DEFER > loop on some machines that are using external bridges, like the > parade-ps8640, found on the ACER Chromebook R13. > > Now that the DSI hosts/devices probe sequence is documented, we can > do adjustments to the mtk_dsi driver as to both fix now and make sure > to avoid this situation in the future: for this, following what is > documented in drm_bridge.c, move the mtk_dsi component_add() to the > mtk_dsi_ops.attach callback and delete it in the detach callback; > keeping in mind that we are registering a drm_bridge for our DSI, > which is only used/attached if the DSI Host is bound, it wouldn't > make sense to keep adding our bridge at probe time (as it would > be useless to have it if mtk_dsi_ops.attach() fails!), so also move > that one to the dsi host attach function (and remove it in detach). > > Cc: <stable@vger.kernel.org> # 5.15.x > Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> > Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com> > Reviewed-by: Jagan Teki <jagan@amarulasolutions.com> Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> Thanks, Nícolas > > --- > drivers/gpu/drm/mediatek/mtk_dsi.c | 167 +++++++++++++++-------------- > 1 file changed, 84 insertions(+), 83 deletions(-) > > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c > index 5d90d2eb0019..bced4c7d668e 100644 > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c > @@ -786,18 +786,101 @@ void mtk_dsi_ddp_stop(struct device *dev) > mtk_dsi_poweroff(dsi); > } > > +static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi) > +{ > + int ret; > + > + ret = drm_simple_encoder_init(drm, &dsi->encoder, > + DRM_MODE_ENCODER_DSI); > + if (ret) { > + DRM_ERROR("Failed to encoder init to drm\n"); > + return ret; > + } > + > + dsi->encoder.possible_crtcs = mtk_drm_find_possible_crtc_by_comp(drm, dsi->host.dev); > + > + ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, > + DRM_BRIDGE_ATTACH_NO_CONNECTOR); > + if (ret) > + goto err_cleanup_encoder; > + > + dsi->connector = drm_bridge_connector_init(drm, &dsi->encoder); > + if (IS_ERR(dsi->connector)) { > + DRM_ERROR("Unable to create bridge connector\n"); > + ret = PTR_ERR(dsi->connector); > + goto err_cleanup_encoder; > + } > + drm_connector_attach_encoder(dsi->connector, &dsi->encoder); > + > + return 0; > + > +err_cleanup_encoder: > + drm_encoder_cleanup(&dsi->encoder); > + return ret; > +} > + > +static int mtk_dsi_bind(struct device *dev, struct device *master, void *data) > +{ > + int ret; > + struct drm_device *drm = data; > + struct mtk_dsi *dsi = dev_get_drvdata(dev); > + > + ret = mtk_dsi_encoder_init(drm, dsi); > + if (ret) > + return ret; > + > + return device_reset_optional(dev); > +} > + > +static void mtk_dsi_unbind(struct device *dev, struct device *master, > + void *data) > +{ > + struct mtk_dsi *dsi = dev_get_drvdata(dev); > + > + drm_encoder_cleanup(&dsi->encoder); > +} > + > +static const struct component_ops mtk_dsi_component_ops = { > + .bind = mtk_dsi_bind, > + .unbind = mtk_dsi_unbind, > +}; > + > static int mtk_dsi_host_attach(struct mipi_dsi_host *host, > struct mipi_dsi_device *device) > { > struct mtk_dsi *dsi = host_to_dsi(host); > + struct device *dev = host->dev; > + int ret; > > dsi->lanes = device->lanes; > dsi->format = device->format; > dsi->mode_flags = device->mode_flags; > + dsi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0); > + if (IS_ERR(dsi->next_bridge)) > + return PTR_ERR(dsi->next_bridge); > + > + drm_bridge_add(&dsi->bridge); > + > + ret = component_add(host->dev, &mtk_dsi_component_ops); > + if (ret) { > + DRM_ERROR("failed to add dsi_host component: %d\n", ret); > + drm_bridge_remove(&dsi->bridge); > + return ret; > + } > > return 0; > } > > +static int mtk_dsi_host_detach(struct mipi_dsi_host *host, > + struct mipi_dsi_device *device) > +{ > + struct mtk_dsi *dsi = host_to_dsi(host); > + > + component_del(host->dev, &mtk_dsi_component_ops); > + drm_bridge_remove(&dsi->bridge); > + return 0; > +} > + > static void mtk_dsi_wait_for_idle(struct mtk_dsi *dsi) > { > int ret; > @@ -938,73 +1021,14 @@ static ssize_t mtk_dsi_host_transfer(struct mipi_dsi_host *host, > > static const struct mipi_dsi_host_ops mtk_dsi_ops = { > .attach = mtk_dsi_host_attach, > + .detach = mtk_dsi_host_detach, > .transfer = mtk_dsi_host_transfer, > }; > > -static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi) > -{ > - int ret; > - > - ret = drm_simple_encoder_init(drm, &dsi->encoder, > - DRM_MODE_ENCODER_DSI); > - if (ret) { > - DRM_ERROR("Failed to encoder init to drm\n"); > - return ret; > - } > - > - dsi->encoder.possible_crtcs = mtk_drm_find_possible_crtc_by_comp(drm, dsi->host.dev); > - > - ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, > - DRM_BRIDGE_ATTACH_NO_CONNECTOR); > - if (ret) > - goto err_cleanup_encoder; > - > - dsi->connector = drm_bridge_connector_init(drm, &dsi->encoder); > - if (IS_ERR(dsi->connector)) { > - DRM_ERROR("Unable to create bridge connector\n"); > - ret = PTR_ERR(dsi->connector); > - goto err_cleanup_encoder; > - } > - drm_connector_attach_encoder(dsi->connector, &dsi->encoder); > - > - return 0; > - > -err_cleanup_encoder: > - drm_encoder_cleanup(&dsi->encoder); > - return ret; > -} > - > -static int mtk_dsi_bind(struct device *dev, struct device *master, void *data) > -{ > - int ret; > - struct drm_device *drm = data; > - struct mtk_dsi *dsi = dev_get_drvdata(dev); > - > - ret = mtk_dsi_encoder_init(drm, dsi); > - if (ret) > - return ret; > - > - return device_reset_optional(dev); > -} > - > -static void mtk_dsi_unbind(struct device *dev, struct device *master, > - void *data) > -{ > - struct mtk_dsi *dsi = dev_get_drvdata(dev); > - > - drm_encoder_cleanup(&dsi->encoder); > -} > - > -static const struct component_ops mtk_dsi_component_ops = { > - .bind = mtk_dsi_bind, > - .unbind = mtk_dsi_unbind, > -}; > - > static int mtk_dsi_probe(struct platform_device *pdev) > { > struct mtk_dsi *dsi; > struct device *dev = &pdev->dev; > - struct drm_panel *panel; > struct resource *regs; > int irq_num; > int ret; > @@ -1021,19 +1045,6 @@ static int mtk_dsi_probe(struct platform_device *pdev) > return ret; > } > > - ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, > - &panel, &dsi->next_bridge); > - if (ret) > - goto err_unregister_host; > - > - if (panel) { > - dsi->next_bridge = devm_drm_panel_bridge_add(dev, panel); > - if (IS_ERR(dsi->next_bridge)) { > - ret = PTR_ERR(dsi->next_bridge); > - goto err_unregister_host; > - } > - } > - > dsi->driver_data = of_device_get_match_data(dev); > > dsi->engine_clk = devm_clk_get(dev, "engine"); > @@ -1098,14 +1109,6 @@ static int mtk_dsi_probe(struct platform_device *pdev) > dsi->bridge.of_node = dev->of_node; > dsi->bridge.type = DRM_MODE_CONNECTOR_DSI; > > - drm_bridge_add(&dsi->bridge); > - > - ret = component_add(&pdev->dev, &mtk_dsi_component_ops); > - if (ret) { > - dev_err(&pdev->dev, "failed to add component: %d\n", ret); > - goto err_unregister_host; > - } > - > return 0; > > err_unregister_host: > @@ -1118,8 +1121,6 @@ static int mtk_dsi_remove(struct platform_device *pdev) > struct mtk_dsi *dsi = platform_get_drvdata(pdev); > > mtk_output_dsi_disable(dsi); > - drm_bridge_remove(&dsi->bridge); > - component_del(&pdev->dev, &mtk_dsi_component_ops); > mipi_dsi_host_unregister(&dsi->host); > > return 0; > -- > 2.33.1 > > > -- > To unsubscribe, send mail to kernel-unsubscribe@lists.collabora.co.uk.
Hi, Angelo: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> 於 2022年1月31日 週一 下午4:55寫道: > > DRM bridge drivers are now attaching their DSI device at probe time, > which requires us to register our DSI host in order to let the bridge > to probe: this recently started producing an endless -EPROBE_DEFER > loop on some machines that are using external bridges, like the > parade-ps8640, found on the ACER Chromebook R13. > > Now that the DSI hosts/devices probe sequence is documented, we can > do adjustments to the mtk_dsi driver as to both fix now and make sure > to avoid this situation in the future: for this, following what is > documented in drm_bridge.c, move the mtk_dsi component_add() to the > mtk_dsi_ops.attach callback and delete it in the detach callback; > keeping in mind that we are registering a drm_bridge for our DSI, > which is only used/attached if the DSI Host is bound, it wouldn't > make sense to keep adding our bridge at probe time (as it would > be useless to have it if mtk_dsi_ops.attach() fails!), so also move > that one to the dsi host attach function (and remove it in detach). Applied to mediatek-drm-fixes[1], thanks. [1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-fixes Regards, Chun-Kuang. > > Cc: <stable@vger.kernel.org> # 5.15.x > Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> > Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com> > Reviewed-by: Jagan Teki <jagan@amarulasolutions.com> > > --- > drivers/gpu/drm/mediatek/mtk_dsi.c | 167 +++++++++++++++-------------- > 1 file changed, 84 insertions(+), 83 deletions(-) > > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c > index 5d90d2eb0019..bced4c7d668e 100644 > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c > @@ -786,18 +786,101 @@ void mtk_dsi_ddp_stop(struct device *dev) > mtk_dsi_poweroff(dsi); > } > > +static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi) > +{ > + int ret; > + > + ret = drm_simple_encoder_init(drm, &dsi->encoder, > + DRM_MODE_ENCODER_DSI); > + if (ret) { > + DRM_ERROR("Failed to encoder init to drm\n"); > + return ret; > + } > + > + dsi->encoder.possible_crtcs = mtk_drm_find_possible_crtc_by_comp(drm, dsi->host.dev); > + > + ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, > + DRM_BRIDGE_ATTACH_NO_CONNECTOR); > + if (ret) > + goto err_cleanup_encoder; > + > + dsi->connector = drm_bridge_connector_init(drm, &dsi->encoder); > + if (IS_ERR(dsi->connector)) { > + DRM_ERROR("Unable to create bridge connector\n"); > + ret = PTR_ERR(dsi->connector); > + goto err_cleanup_encoder; > + } > + drm_connector_attach_encoder(dsi->connector, &dsi->encoder); > + > + return 0; > + > +err_cleanup_encoder: > + drm_encoder_cleanup(&dsi->encoder); > + return ret; > +} > + > +static int mtk_dsi_bind(struct device *dev, struct device *master, void *data) > +{ > + int ret; > + struct drm_device *drm = data; > + struct mtk_dsi *dsi = dev_get_drvdata(dev); > + > + ret = mtk_dsi_encoder_init(drm, dsi); > + if (ret) > + return ret; > + > + return device_reset_optional(dev); > +} > + > +static void mtk_dsi_unbind(struct device *dev, struct device *master, > + void *data) > +{ > + struct mtk_dsi *dsi = dev_get_drvdata(dev); > + > + drm_encoder_cleanup(&dsi->encoder); > +} > + > +static const struct component_ops mtk_dsi_component_ops = { > + .bind = mtk_dsi_bind, > + .unbind = mtk_dsi_unbind, > +}; > + > static int mtk_dsi_host_attach(struct mipi_dsi_host *host, > struct mipi_dsi_device *device) > { > struct mtk_dsi *dsi = host_to_dsi(host); > + struct device *dev = host->dev; > + int ret; > > dsi->lanes = device->lanes; > dsi->format = device->format; > dsi->mode_flags = device->mode_flags; > + dsi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0); > + if (IS_ERR(dsi->next_bridge)) > + return PTR_ERR(dsi->next_bridge); > + > + drm_bridge_add(&dsi->bridge); > + > + ret = component_add(host->dev, &mtk_dsi_component_ops); > + if (ret) { > + DRM_ERROR("failed to add dsi_host component: %d\n", ret); > + drm_bridge_remove(&dsi->bridge); > + return ret; > + } > > return 0; > } > > +static int mtk_dsi_host_detach(struct mipi_dsi_host *host, > + struct mipi_dsi_device *device) > +{ > + struct mtk_dsi *dsi = host_to_dsi(host); > + > + component_del(host->dev, &mtk_dsi_component_ops); > + drm_bridge_remove(&dsi->bridge); > + return 0; > +} > + > static void mtk_dsi_wait_for_idle(struct mtk_dsi *dsi) > { > int ret; > @@ -938,73 +1021,14 @@ static ssize_t mtk_dsi_host_transfer(struct mipi_dsi_host *host, > > static const struct mipi_dsi_host_ops mtk_dsi_ops = { > .attach = mtk_dsi_host_attach, > + .detach = mtk_dsi_host_detach, > .transfer = mtk_dsi_host_transfer, > }; > > -static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi) > -{ > - int ret; > - > - ret = drm_simple_encoder_init(drm, &dsi->encoder, > - DRM_MODE_ENCODER_DSI); > - if (ret) { > - DRM_ERROR("Failed to encoder init to drm\n"); > - return ret; > - } > - > - dsi->encoder.possible_crtcs = mtk_drm_find_possible_crtc_by_comp(drm, dsi->host.dev); > - > - ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, > - DRM_BRIDGE_ATTACH_NO_CONNECTOR); > - if (ret) > - goto err_cleanup_encoder; > - > - dsi->connector = drm_bridge_connector_init(drm, &dsi->encoder); > - if (IS_ERR(dsi->connector)) { > - DRM_ERROR("Unable to create bridge connector\n"); > - ret = PTR_ERR(dsi->connector); > - goto err_cleanup_encoder; > - } > - drm_connector_attach_encoder(dsi->connector, &dsi->encoder); > - > - return 0; > - > -err_cleanup_encoder: > - drm_encoder_cleanup(&dsi->encoder); > - return ret; > -} > - > -static int mtk_dsi_bind(struct device *dev, struct device *master, void *data) > -{ > - int ret; > - struct drm_device *drm = data; > - struct mtk_dsi *dsi = dev_get_drvdata(dev); > - > - ret = mtk_dsi_encoder_init(drm, dsi); > - if (ret) > - return ret; > - > - return device_reset_optional(dev); > -} > - > -static void mtk_dsi_unbind(struct device *dev, struct device *master, > - void *data) > -{ > - struct mtk_dsi *dsi = dev_get_drvdata(dev); > - > - drm_encoder_cleanup(&dsi->encoder); > -} > - > -static const struct component_ops mtk_dsi_component_ops = { > - .bind = mtk_dsi_bind, > - .unbind = mtk_dsi_unbind, > -}; > - > static int mtk_dsi_probe(struct platform_device *pdev) > { > struct mtk_dsi *dsi; > struct device *dev = &pdev->dev; > - struct drm_panel *panel; > struct resource *regs; > int irq_num; > int ret; > @@ -1021,19 +1045,6 @@ static int mtk_dsi_probe(struct platform_device *pdev) > return ret; > } > > - ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, > - &panel, &dsi->next_bridge); > - if (ret) > - goto err_unregister_host; > - > - if (panel) { > - dsi->next_bridge = devm_drm_panel_bridge_add(dev, panel); > - if (IS_ERR(dsi->next_bridge)) { > - ret = PTR_ERR(dsi->next_bridge); > - goto err_unregister_host; > - } > - } > - > dsi->driver_data = of_device_get_match_data(dev); > > dsi->engine_clk = devm_clk_get(dev, "engine"); > @@ -1098,14 +1109,6 @@ static int mtk_dsi_probe(struct platform_device *pdev) > dsi->bridge.of_node = dev->of_node; > dsi->bridge.type = DRM_MODE_CONNECTOR_DSI; > > - drm_bridge_add(&dsi->bridge); > - > - ret = component_add(&pdev->dev, &mtk_dsi_component_ops); > - if (ret) { > - dev_err(&pdev->dev, "failed to add component: %d\n", ret); > - goto err_unregister_host; > - } > - > return 0; > > err_unregister_host: > @@ -1118,8 +1121,6 @@ static int mtk_dsi_remove(struct platform_device *pdev) > struct mtk_dsi *dsi = platform_get_drvdata(pdev); > > mtk_output_dsi_disable(dsi); > - drm_bridge_remove(&dsi->bridge); > - component_del(&pdev->dev, &mtk_dsi_component_ops); > mipi_dsi_host_unregister(&dsi->host); > > return 0; > -- > 2.33.1 >
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