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

[Alex Deucher]

On Mon, Aug 4, 2025 at 12:04 PM Timur Kristóf <timur.kristof at gmail.com> wrote:
>
> 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.

Thanks for clarifying.
Acked-by: Alex Deucher <alexander.deucher at amd.com>

>
> 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
> > >