[PATCH] drm/amdgpu/swm14: Update power limit logic

[Feng, Kenneth]

[AMD Official Use Only - AMD Internal Distribution Only]

Reviewed-by: Kenneth Feng <kenneth.feng at amd.com>


-----Original Message-----
From: Alex Deucher <alexdeucher at gmail.com>
Sent: Wednesday, August 13, 2025 1:39 AM
To: Deucher, Alexander <Alexander.Deucher at amd.com>; Feng, Kenneth <Kenneth.Feng at amd.com>
Cc: amd-gfx at lists.freedesktop.org
Subject: Re: [PATCH] drm/amdgpu/swm14: Update power limit logic

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Ping?

Alex

On Fri, Aug 8, 2025 at 4:29 PM Alex Deucher <alexander.deucher at amd.com> wrote:
>
> Take into account the limits from the vbios.  Ported from the SMU13
> code.
>
> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4352
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> ---
>  .../drm/amd/pm/swsmu/smu14/smu_v14_0_2_ppt.c  | 30
> +++++++++++++++----
>  1 file changed, 25 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu14/smu_v14_0_2_ppt.c
> b/drivers/gpu/drm/amd/pm/swsmu/smu14/smu_v14_0_2_ppt.c
> index 3aea32baea3da..f32474af90b34 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/smu14/smu_v14_0_2_ppt.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu14/smu_v14_0_2_ppt.c
> @@ -1697,9 +1697,11 @@ static int smu_v14_0_2_get_power_limit(struct smu_context *smu,
>                                        uint32_t *min_power_limit)  {
>         struct smu_table_context *table_context = &smu->smu_table;
> +       struct smu_14_0_2_powerplay_table *powerplay_table =
> +               table_context->power_play_table;
>         PPTable_t *pptable = table_context->driver_pptable;
>         CustomSkuTable_t *skutable = &pptable->CustomSkuTable;
> -       uint32_t power_limit;
> +       uint32_t power_limit, od_percent_upper = 0, od_percent_lower =
> + 0;
>         uint32_t msg_limit =
> pptable->SkuTable.MsgLimits.Power[PPT_THROTTLER_PPT0][POWER_SOURCE_AC]
> ;
>
>         if (smu_v14_0_get_current_power_limit(smu, &power_limit)) @@
> -1712,11 +1714,29 @@ static int smu_v14_0_2_get_power_limit(struct smu_context *smu,
>         if (default_power_limit)
>                 *default_power_limit = power_limit;
>
> -       if (max_power_limit)
> -               *max_power_limit = msg_limit;
> +       if (powerplay_table) {
> +               if (smu->od_enabled &&
> +                   smu_v14_0_2_is_od_feature_supported(smu, PP_OD_FEATURE_PPT_BIT)) {
> +                       od_percent_upper = pptable->SkuTable.OverDriveLimitsBasicMax.Ppt;
> +                       od_percent_lower = pptable->SkuTable.OverDriveLimitsBasicMin.Ppt;
> +               } else if (smu_v14_0_2_is_od_feature_supported(smu, PP_OD_FEATURE_PPT_BIT)) {
> +                       od_percent_upper = 0;
> +                       od_percent_lower = pptable->SkuTable.OverDriveLimitsBasicMin.Ppt;
> +               }
> +       }
> +
> +       dev_dbg(smu->adev->dev, "od percent upper:%d, od percent lower:%d (default power: %d)\n",
> +                                       od_percent_upper,
> + od_percent_lower, power_limit);
> +
> +       if (max_power_limit) {
> +               *max_power_limit = msg_limit * (100 + od_percent_upper);
> +               *max_power_limit /= 100;
> +       }
>
> -       if (min_power_limit)
> -               *min_power_limit = 0;
> +       if (min_power_limit) {
> +               *min_power_limit = power_limit * (100 + od_percent_lower);
> +               *min_power_limit /= 100;
> +       }
>
>         return 0;
>  }
> --
> 2.50.1
>