[PATCH 2/6] drm/amd/pm: Disable ULV even if unsupported

[Timur Kristóf]

On Mon, 2025-08-04 at 11:24 -0400, Alex Deucher wrote:
> On Mon, Aug 4, 2025 at 9:58 AM Timur Kristóf
> <timur.kristof at gmail.com> wrote:
> > 
> > This commit fixes some instability on Tahiti.
> > 
> > Sometimes UVD initialization would fail when using DC.
> > I suspect this is because DC doesn't immediately turn on the
> > display clock, so it changes how DPM behaves.
> 
> Is this the right description for this patch?  I thought you had said
> this fixed something else.
> 
> Alex

Yes, this patch together with the previous one fixes the "amdgpu: UVD
Firmware validate fail" when I enable DC on Tahiti.

Last week I thought this also fixed the "si_set_sw_state failed", but
that turned out to be wrong. For that one, I sent a separate patch
which involves a different fix.

Timur

> 
> > 
> > Fixes: 841686df9f7d ("drm/amdgpu: add SI DPM support (v4)")
> > Signed-off-by: Timur Kristóf <timur.kristof at gmail.com>
> > ---
> >  drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c | 7 +++++--
> >  1 file changed, 5 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c
> > b/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c
> > index 52e732be59e3..33b9d4beec84 100644
> > --- a/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c
> > +++ b/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c
> > @@ -5639,10 +5639,13 @@ static int si_disable_ulv(struct
> > amdgpu_device *adev)
> >  {
> >         struct si_power_info *si_pi = si_get_pi(adev);
> >         struct si_ulv_param *ulv = &si_pi->ulv;
> > +       PPSMC_Result r;
> > 
> > +       r = amdgpu_si_send_msg_to_smc(adev, PPSMC_MSG_DisableULV);
> > +
> > +       /* Only care about SMC reply when ULV is supported. */
> >         if (ulv->supported)
> > -               return (amdgpu_si_send_msg_to_smc(adev,
> > PPSMC_MSG_DisableULV) == PPSMC_Result_OK) ?
> > -                       0 : -EINVAL;
> > +               return (r == PPSMC_Result_OK) ? 0 : -EINVAL;
> > 
> >         return 0;
> >  }
> > --
> > 2.50.1
> >