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 <[email protected]>
> ---
> The concept is the same as the previous version.
> https://patchwork.kernel.org/project/linux-mediatek/patch/[email protected]/
> 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;
