drm: Make the vblank disable timer per-crtc

Currently there's one per-device vblank disable timer, and it gets
reset wheneven the vblank refcount for any crtc drops to zero. That
means that one crtc could accidentally be keeping the vblank interrupts
for other crtcs enabled even if there are no users for them. Make the
disable timer per-crtc to avoid this issue.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index ea20c4aa1b6b5a20f15f4818099e60cc040264ac..90c59a8c820f588ac2dfd159f2a095d409d380d7 100644 (file)
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -140,33 +140,34 @@ static void vblank_disable_and_save(struct drm_device *dev, int crtc)
 
 static void vblank_disable_fn(unsigned long arg)
 {
-       struct drm_device *dev = (struct drm_device *)arg;
+       struct drm_vblank_crtc *vblank = (void *)arg;
+       struct drm_device *dev = vblank->dev;
        unsigned long irqflags;
-       int i;
+       int crtc = vblank->crtc;
 
        if (!dev->vblank_disable_allowed)
                return;
 
-       for (i = 0; i < dev->num_crtcs; i++) {
-               spin_lock_irqsave(&dev->vbl_lock, irqflags);
-               if (atomic_read(&dev->vblank[i].refcount) == 0 &&
-                   dev->vblank[i].enabled) {
-                       DRM_DEBUG("disabling vblank on crtc %d\n", i);
-                       vblank_disable_and_save(dev, i);
-               }
-               spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+       spin_lock_irqsave(&dev->vbl_lock, irqflags);
+       if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) {
+               DRM_DEBUG("disabling vblank on crtc %d\n", crtc);
+               vblank_disable_and_save(dev, crtc);
        }
+       spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
 }
 
 void drm_vblank_cleanup(struct drm_device *dev)
 {
+       int crtc;
+
        /* Bail if the driver didn't call drm_vblank_init() */
        if (dev->num_crtcs == 0)
                return;
 
-       del_timer_sync(&dev->vblank_disable_timer);
-
-       vblank_disable_fn((unsigned long)dev);
+       for (crtc = 0; crtc < dev->num_crtcs; crtc++) {
+               del_timer_sync(&dev->vblank[crtc].disable_timer);
+               vblank_disable_fn((unsigned long)&dev->vblank[crtc]);
+       }
 
        kfree(dev->vblank);
 
@@ -178,8 +179,6 @@ int drm_vblank_init(struct drm_device *dev, int num_crtcs)
 {
        int i, ret = -ENOMEM;
 
-       setup_timer(&dev->vblank_disable_timer, vblank_disable_fn,
-                   (unsigned long)dev);
        spin_lock_init(&dev->vbl_lock);
        spin_lock_init(&dev->vblank_time_lock);
 
@@ -189,8 +188,13 @@ int drm_vblank_init(struct drm_device *dev, int num_crtcs)
        if (!dev->vblank)
                goto err;
 
-       for (i = 0; i < num_crtcs; i++)
+       for (i = 0; i < num_crtcs; i++) {
+               dev->vblank[i].dev = dev;
+               dev->vblank[i].crtc = i;
                init_waitqueue_head(&dev->vblank[i].queue);
+               setup_timer(&dev->vblank[i].disable_timer, vblank_disable_fn,
+                           (unsigned long)&dev->vblank[i]);
+       }
 
        DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
 
@@ -900,7 +904,7 @@ void drm_vblank_put(struct drm_device *dev, int crtc)
        /* Last user schedules interrupt disable */
        if (atomic_dec_and_test(&dev->vblank[crtc].refcount) &&
            (drm_vblank_offdelay > 0))
-               mod_timer(&dev->vblank_disable_timer,
+               mod_timer(&dev->vblank[crtc].disable_timer,
                          jiffies + ((drm_vblank_offdelay * HZ)/1000));
 }
 EXPORT_SYMBOL(drm_vblank_put);
@@ -909,8 +913,6 @@ EXPORT_SYMBOL(drm_vblank_put);
  * drm_vblank_off - disable vblank events on a CRTC
  * @dev: DRM device
  * @crtc: CRTC in question
- *
- * Caller must hold event lock.
  */
 void drm_vblank_off(struct drm_device *dev, int crtc)
 {

diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 12f10bc2395f9abcb931938b0915bfac211c7bc2..9d982d483f123ecfdb47d2f2762a7c6759f298eb 100644 (file)
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1024,14 +1024,17 @@ struct drm_pending_vblank_event {
 };
 
 struct drm_vblank_crtc {
+       struct drm_device *dev;         /* pointer to the drm_device */
        wait_queue_head_t queue;        /**< VBLANK wait queue */
        struct timeval time[DRM_VBLANKTIME_RBSIZE];     /**< timestamp of current count */
+       struct timer_list disable_timer;                /* delayed disable timer */
        atomic_t count;                 /**< number of VBLANK interrupts */
        atomic_t refcount;              /* number of users of vblank interruptsper crtc */
        u32 last;                       /* protected by dev->vbl_lock, used */
                                        /* for wraparound handling */
        u32 last_wait;                  /* Last vblank seqno waited per CRTC */
        unsigned int inmodeset;         /* Display driver is setting mode */
+       int crtc;                       /* crtc index */
        bool enabled;                   /* so we don't call enable more than
                                           once per disable */
 };
@@ -1119,7 +1122,6 @@ struct drm_device {
 
        spinlock_t vblank_time_lock;    /**< Protects vblank count and time updates during vblank enable/disable */
        spinlock_t vbl_lock;
-       struct timer_list vblank_disable_timer;
 
        u32 max_vblank_count;           /**< size of vblank counter register */