Re: [PATCH v5 4/4] drm: bridge: ti-sn65dsi83: Add error recovery mechanism

Herve Codina
2025-02-07T18:08:21Z

Hi Alexander,

On Thu, 06 Feb 2025 16:39:09 +0100
Alexander Stein <alexander.stein@ew.tq-group.com> wrote:

> Hi Herve,
>
> Am Donnerstag, 6. Februar 2025, 16:20:48 CET schrieb Herve Codina:
> > Hi Alexander,
> >
> > On Thu, 06 Feb 2025 15:38:42 +0100
> > Alexander Stein <alexander.stein@ew.tq-group.com> wrote:
> >
> > ...
> > > With interrupt configured I got the following stack trace upon
> > > reboot/poweroff:
> > >
> > > [ 91.317264] sn65dsi83 2-002d: reset the pipe
> > > [ 91.344093] Unable to handle ke
> > > ** replaying previous printk message **
> > > [ 91.344093] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
> > ...
> >
> > Ouch :(
> >
> > One question to help me investigating:
> > Do you have the issue at init/probe or when you start to display graphics?
>
> This is during shutdown/poweroff. I assume that regmap_reg() in
> sn65dsi83_handle_errors() fails and because of that reset_work is scheduled.
>

Found the issue.

Can you give me following information so that I can validate what I
understood:
- Is your interrupt line connected directly to the SoC?
- Is there any pullup/pulldown on your interrupt line?
- In your devicetree what is the configuration used for this interrupt in
terms of level or edge.

Anyway, I will send a fix in the next iteration.

Best regards,
Hervé