Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound

[pandora-kernel.git] / drivers / gpu / drm / drm_irq.c

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 3830e9e..44a5d0a 100644 (file)
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -40,6 +40,7 @@
 #include <linux/slab.h>
 
 #include <linux/vgaarb.h>
+#include <linux/export.h>
 
 /* Access macro for slots in vblank timestamp ringbuffer. */
 #define vblanktimestamp(dev, crtc, count) ( \
@@ -109,10 +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);
@@ -163,7 +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)
@@ -406,13 +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;
@@ -885,10 +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.
@@ -908,7 +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]);
@@ -1124,6 +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;
        }
@@ -1204,8 +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)) {