Re: [PATCH v4 6/6] drm/panel: Use managed helpers in assorted panels

["Luca Ceresoli" <luca.ceresoli@bootlin.com>]

On Wed Aug 12, 2026 at 5:53 PM CEST, Osama Abdelkader wrote:
> Use the managed MIPI DSI attach and panel add helpers in assorted
> panel drivers and drop the corresponding manual detach and panel remove
> calls from remove paths.
>
> Suggested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
> Signed-off-by: Osama Abdelkader <osama.abdelkader@gmail.com>
> ---
> v4:
> - use devm_drm_panel_add instead of drm_panel_add.
>
>  drivers/gpu/drm/panel/panel-asus-z00t-tm5p5-n35596.c  | 20 +++--------
>  drivers/gpu/drm/panel/panel-chipwealth-ch13726a.c | 20 +++--------
>  drivers/gpu/drm/panel/panel-dsi-cm.c          | 15 ++++-----
>  drivers/gpu/drm/panel/panel-ebbg-ft8719.c     | 20 +++--------
>  drivers/gpu/drm/panel/panel-elida-kd35t133.c  | 20 +++--------
>  drivers/gpu/drm/panel/panel-feixin-k101-im2ba02.c | 19 +++--------
>  drivers/gpu/drm/panel/panel-feiyang-fy07024di26a30d.c | 19 +++--------
>  drivers/gpu/drm/panel/panel-hydis-hv101hd1.c  | 24 +++-----------
>  drivers/gpu/drm/panel/panel-innolux-p079zca.c | 33 +++----------------
>  drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c  | 19 +++--------
>  drivers/gpu/drm/panel/panel-khadas-ts050.c    | 23 +++----------
>  drivers/gpu/drm/panel/panel-kingdisplay-kd097d04.c    | 30 ++---------------
>  drivers/gpu/drm/panel/panel-lg-sw43408.c      | 22 ++++---------
>  drivers/gpu/drm/panel/panel-lincolntech-lcd197.c  | 20 ++---------
>  drivers/gpu/drm/panel/panel-lxd-m9189a.c      | 24 +++-----------
>  drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c  | 16 +++------
>  drivers/gpu/drm/panel/panel-newvision-nv3051d.c   | 22 +++----------
>  drivers/gpu/drm/panel/panel-orisetech-otm8009a.c  | 16 +++------
>  drivers/gpu/drm/panel/panel-osd-osd101t2587-53ts.c    | 23 +++----------
>  drivers/gpu/drm/panel/panel-panasonic-vvx10f034n00.c  | 31 ++---------------
>  drivers/gpu/drm/panel/panel-ronbo-rb070d30.c  | 19 +++--------
>  drivers/gpu/drm/panel/panel-simple.c          | 22 ++++---------

I think due to its relevance, panel-simple should be a patch on its
own. But see below too.

...

> --- a/drivers/gpu/drm/panel/panel-simple.c
> +++ b/drivers/gpu/drm/panel/panel-simple.c
> @@ -737,7 +737,9 @@ static struct panel_simple *panel_simple_probe(struct device *dev)
>  		goto disable_pm_runtime;
>  	}
>
> -	drm_panel_add(&panel->base);
> +	err = devm_drm_panel_add(dev, &panel->base);
> +	if (err)
> +		goto disable_pm_runtime;
>
>  	return panel;
>
> @@ -785,7 +787,6 @@ static void panel_simple_remove(struct device *dev)
>  {
>  	struct panel_simple *panel = dev_get_drvdata(dev);
>
> -	drm_panel_remove(&panel->base);
>  	panel_simple_shutdown(dev);
>
>  	pm_runtime_dont_use_autosuspend(dev);
> @@ -6551,24 +6552,15 @@ static int panel_simple_dsi_probe(struct mipi_dsi_device *dsi)
>  	dsi->format = desc->format;
>  	dsi->lanes = desc->lanes;
>
> -	err = mipi_dsi_attach(dsi);
> -	if (err) {
> -		struct panel_simple *panel = mipi_dsi_get_drvdata(dsi);
> -
> -		drm_panel_remove(&panel->base);
> -	}
> +	err = devm_mipi_dsi_attach(&dsi->dev, dsi);
> +	if (err)
> +		return err;
>
> -	return err;
> +	return 0;
>  }
>
>  static void panel_simple_dsi_remove(struct mipi_dsi_device *dsi)
>  {
> -	int err;
> -
> -	err = mipi_dsi_detach(dsi);
> -	if (err < 0)
> -		dev_err(&dsi->dev, "failed to detach from DSI host: %d\n", err);
> -
>  	panel_simple_remove(&dsi->dev);
>  }

You are changing the removal order here, with potential risk.

Luca

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com