drm: Core vsync: Add flag DRM_VBLANK_NEXTONMISS.
When this flag is set and the target sequence is missed, wait for the next
vertical blank instead of returning immediately.
Signed-off-by: Dave Airlie <airlied@linux.ie>
diff --git a/drivers/char/drm/drm_irq.c b/drivers/char/drm/drm_irq.c
index b08608a..78aae5b 100644
--- a/drivers/char/drm/drm_irq.c
+++ b/drivers/char/drm/drm_irq.c
@@ -250,8 +250,7 @@
drm_wait_vblank_t vblwait;
struct timeval now;
int ret = 0;
- unsigned int flags;
- atomic_t *seq;
+ unsigned int flags, seq;
if (!dev->irq)
return -EINVAL;
@@ -273,12 +272,12 @@
DRIVER_IRQ_VBL2 : DRIVER_IRQ_VBL))
return -EINVAL;
- seq = (flags & _DRM_VBLANK_SECONDARY) ? &dev->vbl_received2 :
- &dev->vbl_received;
+ seq = atomic_read((flags & _DRM_VBLANK_SECONDARY) ? &dev->vbl_received2
+ : &dev->vbl_received);
switch (vblwait.request.type & _DRM_VBLANK_TYPES_MASK) {
case _DRM_VBLANK_RELATIVE:
- vblwait.request.sequence += atomic_read(seq);
+ vblwait.request.sequence += seq;
vblwait.request.type &= ~_DRM_VBLANK_RELATIVE;
case _DRM_VBLANK_ABSOLUTE:
break;
@@ -286,13 +285,18 @@
return -EINVAL;
}
+ if ((flags & _DRM_VBLANK_NEXTONMISS) &&
+ (seq - vblwait.request.sequence) <= (1<<23)) {
+ vblwait.request.sequence = seq + 1;
+ }
+
if (flags & _DRM_VBLANK_SIGNAL) {
unsigned long irqflags;
drm_vbl_sig_t *vbl_sigs = (flags & _DRM_VBLANK_SECONDARY)
? &dev->vbl_sigs2 : &dev->vbl_sigs;
drm_vbl_sig_t *vbl_sig;
- vblwait.reply.sequence = atomic_read(seq);
+ vblwait.reply.sequence = seq;
spin_lock_irqsave(&dev->vbl_lock, irqflags);