[PATCH] drm/amd/pp: enable power limit increase in OD mode

[Alex Deucher]

On Wed, Oct 10, 2018 at 7:25 PM Greathouse, Joseph
<Joseph.Greathouse at amd.com> wrote:
>
> OverDrive mode allows users to increase the maximum SCLK and MCLK
> frequencies beyond the default on the GPU. However, this may not
> results in large performance gains if the GPU then runs into its TDP
> power limit. This patch adds the capability to increase the power
> limit of a GPU above its default maximum.
>
> This is only allowed when overdrive is enabled in the ppfeaturemask,
> since this is an overdrive feature. The TDPODLimit value from the
> VBIOS describes how how much higher the TDP should be allowed to go
> over its default, in percentage.
>
> Signed-off-by: Joseph Greathouse <Joseph.Greathouse at amd.com>

Reviewed-by: Alex Deucher <alexander.deucher at amd.com>

> ---
>  drivers/gpu/drm/amd/powerplay/amd_powerplay.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/powerplay/amd_powerplay.c b/drivers/gpu/drm/amd/powerplay/amd_powerplay.c
> index 75b56ae..5b0b6b6 100644
> --- a/drivers/gpu/drm/amd/powerplay/amd_powerplay.c
> +++ b/drivers/gpu/drm/amd/powerplay/amd_powerplay.c
> @@ -958,6 +958,7 @@ static int pp_dpm_switch_power_profile(void *handle,
>  static int pp_set_power_limit(void *handle, uint32_t limit)
>  {
>         struct pp_hwmgr *hwmgr = handle;
> +       uint32_t max_power_limit = hwmgr->default_power_limit;
>
>         if (!hwmgr || !hwmgr->pm_en)
>                 return -EINVAL;
> @@ -970,7 +971,12 @@ static int pp_set_power_limit(void *handle, uint32_t limit)
>         if (limit == 0)
>                 limit = hwmgr->default_power_limit;
>
> -       if (limit > hwmgr->default_power_limit)
> +       if (hwmgr->od_enabled) {
> +               max_power_limit *= (100 + hwmgr->platform_descriptor.TDPODLimit);
> +               max_power_limit /= 100;
> +       }
> +
> +       if (limit > max_power_limit)
>                 return -EINVAL;
>
>         mutex_lock(&hwmgr->smu_lock);
> @@ -989,8 +995,13 @@ static int pp_get_power_limit(void *handle, uint32_t *limit, bool default_limit)
>
>         mutex_lock(&hwmgr->smu_lock);
>
> -       if (default_limit)
> +       if (default_limit) {
>                 *limit = hwmgr->default_power_limit;
> +               if (hwmgr->od_enabled) {
> +                       *limit *= (100 + hwmgr->platform_descriptor.TDPODLimit);
> +                       *limit /= 100;
> +               }
> +       }
>         else
>                 *limit = hwmgr->power_limit;
>
> --
> 2.7.4
>
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