[Intel-gfx] [PATCH] drm/i915: Take a runtime pm wakeref for atomic commits

[Ville Syrjälä]

On Tue, May 28, 2019 at 08:53:54AM +0100, Chris Wilson wrote:
> Before we start prepping the system for an atomic modeset, wake the
> device up. We then keep track of this wakeref until we complete the
> atomic commit, so we hold keep the device awake for all potential HW
> access, and do not allow the device to sleep with a pending modeset.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110771
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>

lgtm
Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> ---
>  drivers/gpu/drm/i915/intel_display.c | 5 +++++
>  drivers/gpu/drm/i915/intel_drv.h     | 2 ++
>  2 files changed, 7 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 909171d3ec25..afe7618567c7 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -13811,6 +13811,7 @@ static void intel_atomic_commit_tail(struct drm_atomic_state *state)
>  		intel_uncore_arm_unclaimed_mmio_detection(&dev_priv->uncore);
>  		intel_display_power_put(dev_priv, POWER_DOMAIN_MODESET, wakeref);
>  	}
> +	intel_runtime_pm_put(dev_priv, intel_state->wakeref);
>  
>  	/*
>  	 * Defer the cleanup of the old state to a separate worker to not
> @@ -13889,6 +13890,8 @@ static int intel_atomic_commit(struct drm_device *dev,
>  	struct drm_i915_private *dev_priv = to_i915(dev);
>  	int ret = 0;
>  
> +	intel_state->wakeref = intel_runtime_pm_get(dev_priv);
> +
>  	drm_atomic_state_get(state);
>  	i915_sw_fence_init(&intel_state->commit_ready,
>  			   intel_atomic_commit_ready);
> @@ -13925,6 +13928,7 @@ static int intel_atomic_commit(struct drm_device *dev,
>  	if (ret) {
>  		DRM_DEBUG_ATOMIC("Preparing state failed with %i\n", ret);
>  		i915_sw_fence_commit(&intel_state->commit_ready);
> +		intel_runtime_pm_put(dev_priv, intel_state->wakeref);
>  		return ret;
>  	}
>  
> @@ -13936,6 +13940,7 @@ static int intel_atomic_commit(struct drm_device *dev,
>  		i915_sw_fence_commit(&intel_state->commit_ready);
>  
>  		drm_atomic_helper_cleanup_planes(dev, state);
> +		intel_runtime_pm_put(dev_priv, intel_state->wakeref);
>  		return ret;
>  	}
>  	dev_priv->wm.distrust_bios_wm = false;
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index f341042b6c79..70aff1d6f597 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -420,6 +420,8 @@ struct dpll {
>  struct intel_atomic_state {
>  	struct drm_atomic_state base;
>  
> +	intel_wakeref_t wakeref;
> +
>  	struct {
>  		/*
>  		 * Logical state of cdclk (used for all scaling, watermark,
> -- 
> 2.20.1

-- 
Ville Syrjälä
Intel