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

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/20220530113033.124... 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;