Re: [PATCH v4 8/8] drm/mediatek: Config orientation property if panel provides it

From: Sam Ravnborg
Date: Mon Jun 06 2022 - 15:31:44 EST


Hi Hsin-Yi,

On Mon, Jun 06, 2022 at 11:24:31PM +0800, 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.

I do not know the best way to do what you need to do here.
But it seems wrong to introduce a deprecated function
(drm_of_find_panel_or_bridge), to set the rotation property early.

I think you need to find a way to do this utilising the panel_bridge or
something.

Sam

>
> Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
> Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/mediatek/mtk_dsi.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index d9f10a33e6fa..c56282412bfa 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 +823,12 @@ 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)
> + drm_connector_set_panel_orientation(dsi->connector,
> + drm_panel_get_orientation(dsi->panel));
> +
> drm_connector_attach_encoder(dsi->connector, &dsi->encoder);
>
> return 0;
> @@ -837,6 +844,9 @@ 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 */
> + 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;
> --
> 2.36.1.255.ge46751e96f-goog