drm/vc4: Fix race between page flip completion event and clean-up
There was a small window where a userspace program could submit
a pageflip after receiving a pageflip completion event yet still
receive EBUSY.
Signed-off-by: Derek Foreman <derekf@osg.samsung.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Daniel Stone <daniels@collabora.com>
diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index fef1728..b3064e2 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -442,6 +442,7 @@ int vc4_bo_stats_debugfs(struct seq_file *m, void *arg);
extern struct platform_driver vc4_crtc_driver;
int vc4_enable_vblank(struct drm_device *dev, unsigned int crtc_id);
void vc4_disable_vblank(struct drm_device *dev, unsigned int crtc_id);
+bool vc4_event_pending(struct drm_crtc *crtc);
int vc4_crtc_debugfs_regs(struct seq_file *m, void *arg);
int vc4_crtc_get_scanoutpos(struct drm_device *dev, unsigned int crtc_id,
unsigned int flags, int *vpos, int *hpos,