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

[Alex Deucher]

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

>
> 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
>