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

[Chris Wilson]

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>
---
 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