On HDMI connectors which use drm_bridge_connector and DRM_BRIDGE_OP_HDMI
IGT chokes on the max_bpc property in several kms_properties tests due
to the the drm_bridge_connector failing to reset HDMI-related
properties.

Call __drm_atomic_helper_connector_hdmi_reset() if the
drm_bridge_connector has bridge_hdmi.

It is impossible to call this function from HDMI bridges, there is is no
function that corresponds to the drm_connector_funcs::reset().

Fixes: 6b4468b0c6ba ("drm/bridge-connector: implement glue code for HDMI connector")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/display/Kconfig                |  1 +
 drivers/gpu/drm/display/drm_bridge_connector.c | 13 ++++++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/display/Kconfig b/drivers/gpu/drm/display/Kconfig
index 1a192a45961b..bfd025f8c7b5 100644
--- a/drivers/gpu/drm/display/Kconfig
+++ b/drivers/gpu/drm/display/Kconfig
@@ -9,6 +9,7 @@ config DRM_DISPLAY_HELPER
 config DRM_BRIDGE_CONNECTOR
 	bool
 	depends on DRM && DRM_BRIDGE && DRM_DISPLAY_HELPER
+	select DRM_DISPLAY_HDMI_STATE_HELPER
 	help
 	  DRM connector implementation terminating DRM bridge chains.
 
diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c b/drivers/gpu/drm/display/drm_bridge_connector.c
index 0869b663f17e..7ebb35438459 100644
--- a/drivers/gpu/drm/display/drm_bridge_connector.c
+++ b/drivers/gpu/drm/display/drm_bridge_connector.c
@@ -216,8 +216,19 @@ static void drm_bridge_connector_debugfs_init(struct drm_connector *connector,
 	}
 }
 
+static void drm_bridge_connector_reset(struct drm_connector *connector)
+{
+	struct drm_bridge_connector *bridge_connector =
+		to_drm_bridge_connector(connector);
+
+	drm_atomic_helper_connector_reset(connector);
+	if (bridge_connector->bridge_hdmi)
+		__drm_atomic_helper_connector_hdmi_reset(connector,
+							 connector->state);
+}
+
 static const struct drm_connector_funcs drm_bridge_connector_funcs = {
-	.reset = drm_atomic_helper_connector_reset,
+	.reset = drm_bridge_connector_reset,
 	.detect = drm_bridge_connector_detect,
 	.fill_modes = drm_helper_probe_single_connector_modes,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,

-- 
2.39.2

hi,

On Tue, Jul 02, 2024 at 12:48:55PM GMT, Dmitry Baryshkov wrote:
> On HDMI connectors which use drm_bridge_connector and DRM_BRIDGE_OP_HDMI
> IGT chokes on the max_bpc property in several kms_properties tests due
> to the the drm_bridge_connector failing to reset HDMI-related
> properties.
> 
> Call __drm_atomic_helper_connector_hdmi_reset() if the
> drm_bridge_connector has bridge_hdmi.
> 
> It is impossible to call this function from HDMI bridges, there is is no
> function that corresponds to the drm_connector_funcs::reset().
> 
> Fixes: 6b4468b0c6ba ("drm/bridge-connector: implement glue code for HDMI connector")
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---
>  drivers/gpu/drm/display/Kconfig                |  1 +
>  drivers/gpu/drm/display/drm_bridge_connector.c | 13 ++++++++++++-
>  2 files changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/display/Kconfig b/drivers/gpu/drm/display/Kconfig
> index 1a192a45961b..bfd025f8c7b5 100644
> --- a/drivers/gpu/drm/display/Kconfig
> +++ b/drivers/gpu/drm/display/Kconfig
> @@ -9,6 +9,7 @@ config DRM_DISPLAY_HELPER
>  config DRM_BRIDGE_CONNECTOR
>  	bool
>  	depends on DRM && DRM_BRIDGE && DRM_DISPLAY_HELPER
> +	select DRM_DISPLAY_HDMI_STATE_HELPER

Sorry, I notice it on that patch, but it's really on the previous one:
both DRM_BRIDGE and DRM_DISPLAY_HELPER are meant to be selected, not
depended on.

Otherwise,

Reviewed-by: Maxime Ripard <mripard@kernel.org>

Maxime

On Thu, 4 Jul 2024 at 15:56, Maxime Ripard <mripard@kernel.org> wrote:
>
> hi,
>
> On Tue, Jul 02, 2024 at 12:48:55PM GMT, Dmitry Baryshkov wrote:
> > On HDMI connectors which use drm_bridge_connector and DRM_BRIDGE_OP_HDMI
> > IGT chokes on the max_bpc property in several kms_properties tests due
> > to the the drm_bridge_connector failing to reset HDMI-related
> > properties.
> >
> > Call __drm_atomic_helper_connector_hdmi_reset() if the
> > drm_bridge_connector has bridge_hdmi.
> >
> > It is impossible to call this function from HDMI bridges, there is is no
> > function that corresponds to the drm_connector_funcs::reset().
> >
> > Fixes: 6b4468b0c6ba ("drm/bridge-connector: implement glue code for HDMI connector")
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> > ---
> >  drivers/gpu/drm/display/Kconfig                |  1 +
> >  drivers/gpu/drm/display/drm_bridge_connector.c | 13 ++++++++++++-
> >  2 files changed, 13 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/display/Kconfig b/drivers/gpu/drm/display/Kconfig
> > index 1a192a45961b..bfd025f8c7b5 100644
> > --- a/drivers/gpu/drm/display/Kconfig
> > +++ b/drivers/gpu/drm/display/Kconfig
> > @@ -9,6 +9,7 @@ config DRM_DISPLAY_HELPER
> >  config DRM_BRIDGE_CONNECTOR
> >       bool
> >       depends on DRM && DRM_BRIDGE && DRM_DISPLAY_HELPER
> > +     select DRM_DISPLAY_HDMI_STATE_HELPER
>
> Sorry, I notice it on that patch, but it's really on the previous one:
> both DRM_BRIDGE and DRM_DISPLAY_HELPER are meant to be selected, not
> depended on.

I think they are selected by the 'driver' drivers, but they are
depended upon by the sub-devices. So all bridges depend on DRM_BRIDGE
(either directly or via the menu entry).
All drm/display modules depend on DRM_DISPLAY_HELPER. I agree that it
might be worth changing the second part (most likely in a separate
series, ok), but I'm sure that the DRM_BRIDGE part is correct.


>
> Otherwise,
>
> Reviewed-by: Maxime Ripard <mripard@kernel.org>
>
> Maxime



-- 
With best wishes
Dmitry