[RFC 05/17] drm/vblank: Annotate with dma-fence signalling section

[Daniel Vetter]

This is rather overkill since currently all drivers call this from
hardirq (or at least timers). But maybe in the future we're going to
have thread irq handlers and what not, doesn't hurt to be prepared.
Plus this is an easy start for sprinkling these fence annotations into
shared code.

Cc: linux-media at vger.kernel.org
Cc: linaro-mm-sig at lists.linaro.org
Cc: linux-rdma at vger.kernel.org
Cc: amd-gfx at lists.freedesktop.org
Cc: intel-gfx at lists.freedesktop.org
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Cc: Christian König <christian.koenig at amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
---
 drivers/gpu/drm/drm_vblank.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index 758bf74e1cab..125ef0c0f9a1 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -24,6 +24,7 @@
  * OTHER DEALINGS IN THE SOFTWARE.
  */
 
+#include <linux/dma-fence.h>
 #include <linux/export.h>
 #include <linux/moduleparam.h>
 
@@ -1895,7 +1896,7 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
 {
 	struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
 	unsigned long irqflags;
-	bool disable_irq;
+	bool disable_irq, fence_cookie;
 
 	if (WARN_ON_ONCE(!dev->num_crtcs))
 		return false;
@@ -1903,6 +1904,8 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
 	if (WARN_ON(pipe >= dev->num_crtcs))
 		return false;
 
+	fence_cookie = dma_fence_begin_signalling();
+
 	spin_lock_irqsave(&dev->event_lock, irqflags);
 
 	/* Need timestamp lock to prevent concurrent execution with
@@ -1915,6 +1918,7 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
 	if (!vblank->enabled) {
 		spin_unlock(&dev->vblank_time_lock);
 		spin_unlock_irqrestore(&dev->event_lock, irqflags);
+		dma_fence_end_signalling(fence_cookie);
 		return false;
 	}
 
@@ -1940,6 +1944,8 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
 	if (disable_irq)
 		vblank_disable_fn(&vblank->disable_timer);
 
+	dma_fence_end_signalling(fence_cookie);
+
 	return true;
 }
 EXPORT_SYMBOL(drm_handle_vblank);
-- 
2.26.2