drm/nouveau: always queue flips relative to kernel channel activity
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_display.c b/drivers/gpu/drm/nouveau/nouveau_display.c
index 547c42b..4b124a6 100644
--- a/drivers/gpu/drm/nouveau/nouveau_display.c
+++ b/drivers/gpu/drm/nouveau/nouveau_display.c
@@ -591,7 +591,7 @@
struct nouveau_bo *old_bo = nouveau_framebuffer(crtc->fb)->nvbo;
struct nouveau_bo *new_bo = nouveau_framebuffer(fb)->nvbo;
struct nouveau_page_flip_state *s;
- struct nouveau_channel *chan = NULL;
+ struct nouveau_channel *chan = drm->channel;
struct nouveau_fence *fence;
int ret;
@@ -602,14 +602,13 @@
if (!s)
return -ENOMEM;
- /* Choose the channel the flip will be handled in */
- spin_lock(&old_bo->bo.bdev->fence_lock);
- fence = new_bo->bo.sync_obj;
- if (fence)
- chan = fence->channel;
- if (!chan)
- chan = drm->channel;
- spin_unlock(&old_bo->bo.bdev->fence_lock);
+ /* synchronise rendering channel with the kernel's channel */
+ spin_lock(&new_bo->bo.bdev->fence_lock);
+ fence = nouveau_fence_ref(new_bo->bo.sync_obj);
+ spin_unlock(&new_bo->bo.bdev->fence_lock);
+ ret = nouveau_fence_sync(fence, chan);
+ if (ret)
+ return ret;
if (new_bo != old_bo) {
ret = nouveau_bo_pin(new_bo, TTM_PL_FLAG_VRAM);