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[8/8] drm/mediatek: Config orientation property if panel provides it

Message ID 20220601081823.1038797-9-hsinyi@chromium.org (mailing list archive)
State New, archived
Headers show
Series Add a panel API to return panel orientation | expand

Commit Message

Hsin-Yi Wang June 1, 2022, 8:18 a.m. UTC
Panel orientation property should be set before drm_dev_register().
Mediatek drm driver calls drm_dev_register() in .bind(). However, most
panels sets orientation property relatively late, mostly in .get_modes()
callback, since this is when they are able to get the connector and
binds the orientation property to it, though the value should be known
when the panel is probed.

Let the drm driver check if the remote end point is a panel and if it
contains the orientation property. If it does, set it before
drm_dev_register() is called.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
---
The concept is the same as the previous version.
https://patchwork.kernel.org/project/linux-mediatek/patch/20220530113033.124072-1-hsinyi@chromium.org/
The only difference is, it now uses the panel API instead of parsing
orientation from the driver.
---
 drivers/gpu/drm/mediatek/mtk_dsi.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

Comments

Hans de Goede June 1, 2022, 8:57 a.m. UTC | #1
Hi,

On 6/1/22 10:18, Hsin-Yi Wang wrote:
> Panel orientation property should be set before drm_dev_register().
> Mediatek drm driver calls drm_dev_register() in .bind(). However, most
> panels sets orientation property relatively late, mostly in .get_modes()
> callback, since this is when they are able to get the connector and
> binds the orientation property to it, though the value should be known
> when the panel is probed.
> 
> Let the drm driver check if the remote end point is a panel and if it
> contains the orientation property. If it does, set it before
> drm_dev_register() is called.
> 
> Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
> ---
> The concept is the same as the previous version.
> https://patchwork.kernel.org/project/linux-mediatek/patch/20220530113033.124072-1-hsinyi@chromium.org/
> The only difference is, it now uses the panel API instead of parsing
> orientation from the driver.
> ---
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index bd3f5b485085..12836a697f56 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -185,6 +185,7 @@ struct mtk_dsi {
>  	struct drm_encoder encoder;
>  	struct drm_bridge bridge;
>  	struct drm_bridge *next_bridge;
> +	struct drm_panel *panel;
>  	struct drm_connector *connector;
>  	struct phy *phy;
>  
> @@ -822,6 +823,16 @@ static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
>  		ret = PTR_ERR(dsi->connector);
>  		goto err_cleanup_encoder;
>  	}
> +
> +	/* Read panel orientation */
> +	if (dsi->panel) {
> +		enum drm_panel_orientation orientation;
> +
> +		orientation = drm_panel_get_orientation(dsi->panel);
> +		if (orientation != DRM_MODE_PANEL_ORIENTATION_UNKNOWN)
> +			drm_connector_set_panel_orientation(dsi->connector, orientation);
> +	}
> +
>  	drm_connector_attach_encoder(dsi->connector, &dsi->encoder);
>  
>  	return 0;

drm_connector_set_panel_orientation() is a no-op when called with 
DRM_MODE_PANEL_ORIENTATION_UNKNOWN, so the check for this is not
necessary. This allows this to be simplified to:

	/* Read panel orientation */
	if (dsi->panel)
		drm_connector_set_panel_orientation(dsi->connector,
						    drm_panel_get_orientation(dsi->panel));


Note since drm_panel_get_orientation() checks for a NULL panel, you could even
drop the "if (dsi->panel)", but I think the meaning of the code is more
clear with that present.






> @@ -837,6 +848,9 @@ static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
>  	struct drm_device *drm = data;
>  	struct mtk_dsi *dsi = dev_get_drvdata(dev);
>  
> +	/* Get panel if existed */
> +	ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, &dsi->panel, NULL);
> +

Check ret? or maybe not assign to ret ?    I understand some errors are expected
so maybe something like:

	if (ret && ret != -ENODEV)
		return ret;

?

Note -ENODEV is probably not the right error the check for!

Regards,

Hans



>  	ret = mtk_dsi_encoder_init(drm, dsi);
>  	if (ret)
>  		return ret;
Hsin-Yi Wang June 1, 2022, 9:29 a.m. UTC | #2
On Wed, Jun 1, 2022 at 4:57 PM Hans de Goede <hdegoede@redhat.com> wrote:
>
> Hi,
>
> On 6/1/22 10:18, Hsin-Yi Wang wrote:
> > Panel orientation property should be set before drm_dev_register().
> > Mediatek drm driver calls drm_dev_register() in .bind(). However, most
> > panels sets orientation property relatively late, mostly in .get_modes()
> > callback, since this is when they are able to get the connector and
> > binds the orientation property to it, though the value should be known
> > when the panel is probed.
> >
> > Let the drm driver check if the remote end point is a panel and if it
> > contains the orientation property. If it does, set it before
> > drm_dev_register() is called.
> >
> > Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
> > ---
> > The concept is the same as the previous version.
> > https://patchwork.kernel.org/project/linux-mediatek/patch/20220530113033.124072-1-hsinyi@chromium.org/
> > The only difference is, it now uses the panel API instead of parsing
> > orientation from the driver.
> > ---
> >  drivers/gpu/drm/mediatek/mtk_dsi.c | 14 ++++++++++++++
> >  1 file changed, 14 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> > index bd3f5b485085..12836a697f56 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> > @@ -185,6 +185,7 @@ struct mtk_dsi {
> >       struct drm_encoder encoder;
> >       struct drm_bridge bridge;
> >       struct drm_bridge *next_bridge;
> > +     struct drm_panel *panel;
> >       struct drm_connector *connector;
> >       struct phy *phy;
> >
> > @@ -822,6 +823,16 @@ static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
> >               ret = PTR_ERR(dsi->connector);
> >               goto err_cleanup_encoder;
> >       }
> > +
> > +     /* Read panel orientation */
> > +     if (dsi->panel) {
> > +             enum drm_panel_orientation orientation;
> > +
> > +             orientation = drm_panel_get_orientation(dsi->panel);
> > +             if (orientation != DRM_MODE_PANEL_ORIENTATION_UNKNOWN)
> > +                     drm_connector_set_panel_orientation(dsi->connector, orientation);
> > +     }
> > +
> >       drm_connector_attach_encoder(dsi->connector, &dsi->encoder);
> >
> >       return 0;
>
> drm_connector_set_panel_orientation() is a no-op when called with
> DRM_MODE_PANEL_ORIENTATION_UNKNOWN, so the check for this is not
> necessary. This allows this to be simplified to:
>
>         /* Read panel orientation */
>         if (dsi->panel)
>                 drm_connector_set_panel_orientation(dsi->connector,
>                                                     drm_panel_get_orientation(dsi->panel));
>
>
> Note since drm_panel_get_orientation() checks for a NULL panel, you could even
> drop the "if (dsi->panel)", but I think the meaning of the code is more
> clear with that present.
>
Will update this
>
>
>
>
>
> > @@ -837,6 +848,9 @@ static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
> >       struct drm_device *drm = data;
> >       struct mtk_dsi *dsi = dev_get_drvdata(dev);
> >
> > +     /* Get panel if existed */
> > +     ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, &dsi->panel, NULL);
> > +
>
> Check ret? or maybe not assign to ret ?    I understand some errors are expected
> so maybe something like:
>
>         if (ret && ret != -ENODEV)
>                 return ret;
>
I will choose not to assign ret. In some cases that the end point is a
bridge (not panel), since we assign NULL to the bridge, we will get
EPROBE_DEFER.

If the panel fails at this stage,
drm_connector_set_panel_orientation() is just a no-op. Let dsi still
be able to be binded.


> ?
>
> Note -ENODEV is probably not the right error the check for!
>
> Regards,
>
> Hans
>
>
>
> >       ret = mtk_dsi_encoder_init(drm, dsi);
> >       if (ret)
> >               return ret;
>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index bd3f5b485085..12836a697f56 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -185,6 +185,7 @@  struct mtk_dsi {
 	struct drm_encoder encoder;
 	struct drm_bridge bridge;
 	struct drm_bridge *next_bridge;
+	struct drm_panel *panel;
 	struct drm_connector *connector;
 	struct phy *phy;
 
@@ -822,6 +823,16 @@  static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
 		ret = PTR_ERR(dsi->connector);
 		goto err_cleanup_encoder;
 	}
+
+	/* Read panel orientation */
+	if (dsi->panel) {
+		enum drm_panel_orientation orientation;
+
+		orientation = drm_panel_get_orientation(dsi->panel);
+		if (orientation != DRM_MODE_PANEL_ORIENTATION_UNKNOWN)
+			drm_connector_set_panel_orientation(dsi->connector, orientation);
+	}
+
 	drm_connector_attach_encoder(dsi->connector, &dsi->encoder);
 
 	return 0;
@@ -837,6 +848,9 @@  static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
 	struct drm_device *drm = data;
 	struct mtk_dsi *dsi = dev_get_drvdata(dev);
 
+	/* Get panel if existed */
+	ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, &dsi->panel, NULL);
+
 	ret = mtk_dsi_encoder_init(drm, dsi);
 	if (ret)
 		return ret;