[PATCH] drm/i915: Wait one vblank for pipe CRC transition

[Mika Kahola]

Let's test if we need to wait for a vblank while transitioning from
none to real source. Let's give CI a go and see the outcome.

Signed-off-by: Mika Kahola <mika.kahola at intel.com>
---
 drivers/gpu/drm/i915/intel_pipe_crc.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_pipe_crc.c b/drivers/gpu/drm/i915/intel_pipe_crc.c
index 4f367c1..3c81d6b 100644
--- a/drivers/gpu/drm/i915/intel_pipe_crc.c
+++ b/drivers/gpu/drm/i915/intel_pipe_crc.c
@@ -621,6 +621,7 @@ static int pipe_crc_set_source(struct drm_i915_private *dev_priv,
 			       enum intel_pipe_crc_source source)
 {
 	struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe];
+	struct intel_crtc *crtc = intel_get_crtc_for_pipe(dev_priv, pipe);
 	enum intel_display_power_domain power_domain;
 	u32 val = 0; /* shut up gcc */
 	int ret;
@@ -657,6 +658,11 @@ static int pipe_crc_set_source(struct drm_i915_private *dev_priv,
 			goto out;
 		}
 
+		drm_modeset_lock(&crtc->base.mutex, NULL);
+		if (crtc->base.state->active)
+			intel_wait_for_vblank(dev_priv, pipe);
+		drm_modeset_unlock(&crtc->base.mutex);
+
 		spin_lock_irq(&pipe_crc->lock);
 		kfree(pipe_crc->entries);
 		pipe_crc->entries = entries;
@@ -673,8 +679,6 @@ static int pipe_crc_set_source(struct drm_i915_private *dev_priv,
 	/* real source -> none transition */
 	if (!source) {
 		struct intel_pipe_crc_entry *entries;
-		struct intel_crtc *crtc = intel_get_crtc_for_pipe(dev_priv,
-								  pipe);
 
 		DRM_DEBUG_DRIVER("stopping CRCs for pipe %c\n",
 				 pipe_name(pipe));
-- 
2.7.4