[RFC 2/3] drm/atomic: Call dma_fence_boost() when we've missed a vblank

[Rob Clark]

From: Rob Clark <robdcl...@chromium.org>

Signed-off-by: Rob Clark <robdcl...@chromium.org>
---
 drivers/gpu/drm/drm_atomic_helper.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic_helper.c 
b/drivers/gpu/drm/drm_atomic_helper.c
index 560aaecba31b..fe10fc2e7f86 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1435,11 +1435,15 @@ int drm_atomic_helper_wait_for_fences(struct drm_device 
*dev,
        int i, ret;
 
        for_each_new_plane_in_state(state, plane, new_plane_state, i) {
+               u64 vblank_count;
+
                if (!new_plane_state->fence)
                        continue;
 
                WARN_ON(!new_plane_state->fb);
 
+               vblank_count = drm_crtc_vblank_count(new_plane_state->crtc);
+
                /*
                 * If waiting for fences pre-swap (ie: nonblock), userspace can
                 * still interrupt the operation. Instead of blocking until the
@@ -1449,6 +1453,13 @@ int drm_atomic_helper_wait_for_fences(struct drm_device 
*dev,
                if (ret)
                        return ret;
 
+               /*
+                * Check if we've missed a vblank while waiting, and if we have
+                * signal the fence that it's signaler should be boosted
+                */
+               if (vblank_count != 
drm_crtc_vblank_count(new_plane_state->crtc))
+                       dma_fence_boost(new_plane_state->fence);
+
                dma_fence_put(new_plane_state->fence);
                new_plane_state->fence = NULL;
        }
-- 
2.30.2