Re: [PATCH v4] drm/amd/pm: defer UCLK DPM on selected Apple Navi GPUs

[Alex Deucher]

On Fri, Oct 30, 2026 at 7:30 AM André Eikmeyer <dev@deq.rocks> wrote:
>
> On Thu, 29 Oct 2026 17:57:49 -0400
> Alex Deucher <alexdeucher@xxxxxxxxx> wrote:
>
> > @Andre Eikmeyer I think this patch should fix your system as well.
>
> Hi Alex,
>
> I guess you have seen it already but the patch doesn't match the 16,1.
> Its boards are 7340/020f and 7340/0210, and v4 only matches 0218, 0219
> and 021a.
>
> That hang is what I sent a fix for
> https://lore.kernel.org/all/20261024162109.307247-1-dev@deq.rocks/
>
> The VBIOS trains the UMC p-states at different frequencies the pp-table
> lists. The SMU hangs as soon as UCLK switches into level 2. Deferring
> the UCLK enable doesn't change the levels, so the hang just moves from
> boot to later under load.
>

It is the same issue.  I don't want two fixes for the same issue. I
just sent an updated version of this patch expanded to cover more
macs.

Alex

> The two patches can coexist after a trivial rebase.
>
> > ...your system...
>
> I need to clarify here. I actually don't own a 16,1. But I maintain a
> distro (KaiT2en) that specializes on T2 Macs. So the patches I develop
> are extensively tested by the community before submitting. Atharwa is
> part of this community. Ed is not, but Atharwa reviewed and tested the
> code.
>
> Best,
> Andre