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

[Ying Liu]

On Wednesday, November 22, 2023 9:59 PM, Linus Walleij <linus.walleij@xxxxxxxxxx> wrote:
> Hi Ying,

Hi Linus,

> 
> 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.

Will add it.

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

Thanks for the test.

> 
> Can you send it as a proper patch?

Will do.

Regards,
Liu Ying