amdgpu link problem (was Re: [git pull] drm for 5.18-rc1)

[Alex Deucher]

On Mon, Mar 28, 2022 at 9:54 PM Linus Torvalds
<torvalds at linux-foundation.org> wrote:
>
> I didn't notice this until now, probably because everything still
> _works_, but I get a new big warning splat at bootup on my main
> workstation these days as of the merge window changes.
>
> The full warning is attached, but it's basically the ASSERT(0) at line 938 in
>
>   drivers/gpu/drm/amd/display/dc/core/dc_link.c
>
> and it looks to have been introduced by commit c282d9512cdd
> ("drm/amd/display: factor out dp detection link training and mst top
> detection").
>
> This is the same old setup I've reported before, with some random
> Radeon card with two monitors attached (PCI ID 1002:67df rev e7,
> subsystem ID 1da2:e353).
>
> I think the card went by the name "Sapphire Pulse RX 580 8GB" in case
> any of that matters, but it's been working fine.
>
> It still works fine, it just has a big ugly boot-time splat.
>
> As mentioned, two 4K monitors attached, both over HDMI.

I think it should be fixed with this patch which is already queued up
in my -fixes PR from last week:
https://gitlab.freedesktop.org/agd5f/linux/-/commit/a572f7055067d95455850fd242d8b54ff5786cac

Alex

>
> If there is any particular info you want, just let me know where/how
> to find it, and I can provide.
>
>                       Linus