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path: root/drivers/gpu/drm/drm_irq.c
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Diffstat (limited to 'drivers/gpu/drm/drm_irq.c')
-rw-r--r--drivers/gpu/drm/drm_irq.c31
1 files changed, 15 insertions, 16 deletions
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index cb3794a00f98..44a5d0ad8b7c 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -110,10 +110,7 @@ static void vblank_disable_and_save(struct drm_device *dev, int crtc)
/* Prevent vblank irq processing while disabling vblank irqs,
* so no updates of timestamps or count can happen after we've
* disabled. Needed to prevent races in case of delayed irq's.
- * Disable preemption, so vblank_time_lock is held as short as
- * possible, even under a kernel with PREEMPT_RT patches.
*/
- preempt_disable();
spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
dev->driver->disable_vblank(dev, crtc);
@@ -164,7 +161,6 @@ static void vblank_disable_and_save(struct drm_device *dev, int crtc)
clear_vblank_timestamps(dev, crtc);
spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
- preempt_enable();
}
static void vblank_disable_fn(unsigned long arg)
@@ -407,13 +403,16 @@ int drm_irq_uninstall(struct drm_device *dev)
/*
* Wake up any waiters so they don't hang.
*/
- spin_lock_irqsave(&dev->vbl_lock, irqflags);
- for (i = 0; i < dev->num_crtcs; i++) {
- DRM_WAKEUP(&dev->vbl_queue[i]);
- dev->vblank_enabled[i] = 0;
- dev->last_vblank[i] = dev->driver->get_vblank_counter(dev, i);
+ if (dev->num_crtcs) {
+ spin_lock_irqsave(&dev->vbl_lock, irqflags);
+ for (i = 0; i < dev->num_crtcs; i++) {
+ DRM_WAKEUP(&dev->vbl_queue[i]);
+ dev->vblank_enabled[i] = 0;
+ dev->last_vblank[i] =
+ dev->driver->get_vblank_counter(dev, i);
+ }
+ spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
}
- spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
if (!irq_enabled)
return -EINVAL;
@@ -886,10 +885,6 @@ int drm_vblank_get(struct drm_device *dev, int crtc)
spin_lock_irqsave(&dev->vbl_lock, irqflags);
/* Going from 0->1 means we have to enable interrupts again */
if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1) {
- /* Disable preemption while holding vblank_time_lock. Do
- * it explicitely to guard against PREEMPT_RT kernel.
- */
- preempt_disable();
spin_lock_irqsave(&dev->vblank_time_lock, irqflags2);
if (!dev->vblank_enabled[crtc]) {
/* Enable vblank irqs under vblank_time_lock protection.
@@ -909,7 +904,6 @@ int drm_vblank_get(struct drm_device *dev, int crtc)
}
}
spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags2);
- preempt_enable();
} else {
if (!dev->vblank_enabled[crtc]) {
atomic_dec(&dev->vblank_refcount[crtc]);
@@ -1125,6 +1119,7 @@ static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
trace_drm_vblank_event_delivered(current->pid, pipe,
vblwait->request.sequence);
} else {
+ /* drm_handle_vblank_events will call drm_vblank_put */
list_add_tail(&e->base.link, &dev->vblank_event_list);
vblwait->reply.sequence = vblwait->request.sequence;
}
@@ -1205,8 +1200,12 @@ int drm_wait_vblank(struct drm_device *dev, void *data,
goto done;
}
- if (flags & _DRM_VBLANK_EVENT)
+ if (flags & _DRM_VBLANK_EVENT) {
+ /* must hold on to the vblank ref until the event fires
+ * drm_vblank_put will be called asynchronously
+ */
return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
+ }
if ((flags & _DRM_VBLANK_NEXTONMISS) &&
(seq - vblwait->request.sequence) <= (1<<23)) {
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