Re: [PATCH v3] drm/bridge: panel: Add a device link between drm device and panel device

[Linus Walleij]

Hi Ying,

On Mon, Nov 20, 2023 at 11:08 AM Ying Liu <victor.liu@xxxxxxx> wrote:

[Me]
> > > v2->v3:
> > > * Improve commit message s/swapped/reversed/.
> >
> > This patch causes a regression in the Ux500 MCDE
> > drivers/gpu/drm/mcde/* driver with the nt35510 panel
> > drivers/gpu/drm/panel/panel-novatek-nt35510.c
> > my dmesg looks like this:
(...)
> Sorry for the breakage and a bit late response(I'm a bit busy with internal
> things).
>
> I think device_link_add() fails because a0351000.dsi.0 already depends
> on a0350000.mcde.  Can you confirm that device_link_add() returns NULL
> right after it calls device_is_dependent()?
>
> Does this patch fix the issue?

Yep it works!

You missed one device_link_del() instance on the errorpath.

Tested-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

Can you send it as a proper patch?

Yours,
Linus Walleij