[Intel-gfx] [PATCH] drm/i915: Disable DMC powersaving during GT operations

[Chris Wilson]

Quoting Chris Wilson (2017-09-12 13:37:32)
> diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
> index 813a3b546d6e..3c8ebdb5b0b4 100644
> --- a/drivers/gpu/drm/i915/i915_gem_request.c
> +++ b/drivers/gpu/drm/i915/i915_gem_request.c
> @@ -254,6 +254,9 @@ static void mark_busy(struct drm_i915_private *i915)
>         intel_runtime_pm_get_noresume(i915);
>         i915->gt.awake = true;
>  

/*
 * The DMC doesn't behave well when it is active (i.e the system is
 * idle). It continually tries to toggle DC_STATE_EN causing a
 * severe slow down of the rest of the system (severe enough to trigger
 * watchdogs and reboot the machine under CI testing).
 *
 * Known affected firmware:
 * - skl_dmc_ver1_26.bin
 * - bxt_dmc_ver1_07.bin
 */
> +       if (i915->csr.dmc_payload)
> +               intel_display_power_get(i915, POWER_DOMAIN_MODESET);
> +