[PATCH 06/18] drm/vblank: Annotate with dma-fence signalling section

Daniel Vetter
2020-06-04T08:12:45Z

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@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: linux-rdma@vger.kernel.org
Cc: amd-gfx@lists.freedesktop.org
Cc: intel-gfx@lists.freedesktop.org
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Christian König <christian.koenig@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@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 85e5f2db1608..93a5bba5f665 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>

@@ -1908,7 +1909,7 @@ 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 (drm_WARN_ON_ONCE(dev, !drm_dev_has_vblank(dev)))
return false;
@@ -1916,6 +1917,8 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
if (drm_WARN_ON(dev, 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
@@ -1928,6 +1931,7 @@ 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;
}

@@ -1953,6 +1957,8 @@ 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