Re: [PATCH v5 4/4] drm/panel: simple: Use managed helpers in panel-simple

[Osama Abdelkader]

Hello Luca,

Thanks for the reply.

On Wed, Sep 16, 2026 at 09:50:35AM +0200, Luca Ceresoli wrote:
> Hello Osama,
> 
> On Tue Sep 15, 2026 at 4:59 PM CEST, Osama Abdelkader wrote:
> > Use the managed panel add helper in panel-simple and drop the manual
> > panel remove call from the remove path.
> >
> > Keep the MIPI DSI attach and detach manual, since panel-simple's
> > remove callback also unprepares/disables the panel and releases the
> > DDC adapter; deferring the detach to devm would run it after that
> > cleanup instead of before, changing the teardown order.
> >
> > Suggested-by: Luca Ceresoli <luca.ceresoli@xxxxxxxxxxx>
> > Signed-off-by: Osama Abdelkader <osama.abdelkader@xxxxxxxxx>
> 
> Thanks for continuing the cleanup.
> 
> However there is still some confusion in how you are sending patch series:
> 
>  * You sent the patches to various recipients including mailing lists
>    (which is OK), but did not send the cover letter to mailing lists. I got
>    the cover and it only has me in To: and nobody in Cc:.
> 

I see, I used:
git send-email --to-cmd='scripts/get_maintainer.pl --no-rolestats' --to=luca.ceresoli@xxxxxxxxxxx v6-000*
get_maintainer.pl doesn't return maintainer for the cover letter.
Thanks for the notice, will fix that.

>  * You sent two iterations the same day without an explanation; this is
>    normally a confusing behaviour, which makes sense only rarely and for a
>    very good reason which is clearly explained in reply to the previous
>    revision (e.g. "sorry, this series is broken, ignore it, sending a fixed
>    one very soon")
>

Sorry for the confusion, once I sent v5 sashiko-bot caught couple of issues
including compile errors, that's why I was in rush to fix that.

>  * The panel-simple patch disappeared in v6, why? (see next question)
>

There was a concern from sashiko-bot on v5 that the devm_ changes in panel-simple
may lead to use-after-free window, that's why I excluded patch 4 in v6.
I have to write that in changelog, yes.

>  * The Changelog for v6 (not visible on mailing lists) is overly verbose,
>    so I didn't even try reading it. Please use oneliners or so. And in case
>    you did, don't uncritically copy-paste AI slop. Think about your readers
>    and te minimum info they need.

I see, I took sashiko report copy/paste. It's too verbose, will clean it up
and summarize it in next version.

> 
> I think I already suggested using b4 to send your patches, which would
> handle the mechanical aspects for you. It prevent issues like the first
> bullet above.

I will try it, I just didn't use it before and didn't want to make something
wrong so tried to stick to git send-email.

> 
> Can you please send a v7 with the above fixed, as well as the changelog
> made concise (including the v5 and v6 entries)? I'll be glad to review
> that.
>

Sure, thanks.
 
> Kind regards,
> Luca
>

Kind regards,
Osama
 
> > ---
> >  drivers/gpu/drm/panel/panel-simple.c | 15 ++++-----------
> >  1 file changed, 4 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
> > index c95964ba25a9..02d21dde5766 100644
> > --- 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);
> > @@ -6540,7 +6541,6 @@ static int panel_simple_dsi_probe(struct mipi_dsi_device *dsi)
> >  {
> >  	const struct panel_desc_dsi *desc;
> >  	struct panel_simple *panel;
> > -	int err;
> >
> >  	panel = panel_simple_probe(&dsi->dev);
> >  	if (IS_ERR(panel))
> > @@ -6551,14 +6551,7 @@ 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);
> > -	}
> > -
> > -	return err;
> > +	return mipi_dsi_attach(dsi);
> >  }
> >
> >  static void panel_simple_dsi_remove(struct mipi_dsi_device *dsi)
> 
> 
> 
> 
> 
> --
> Luca Ceresoli, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com