On Wed, Jun 1, 2022 at 4:57 PM Hans de Goede <hdegoede@xxxxxxxxxx> 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@xxxxxxxxxxxx> > > --- > > The concept is the same as the previous version. > > https://patchwork.kernel.org/project/linux-mediatek/patch/20220530113033.124072-1-hsinyi@xxxxxxxxxxxx/ > > 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; >
