drm: don't call the vblank tasklet with irqs disabled.

If a specific tasklet shares data with irq context,
it needs to take a private irq-blocking spinlock within
the tasklet itself.

Signed-off-by: Dave Airlie <airlied@redhat.com>

2 files changed, 17 insertions, 15 deletions

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 089c015c01d1..53f0e5af1cc8 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -400,27 +400,31 @@ static void drm_locked_tasklet_func(unsigned long data)
 {
         struct drm_device *dev = (struct drm_device *)data;
         unsigned long irqflags;
-
+        void (*tasklet_func)(struct drm_device *);
+        
         spin_lock_irqsave(&dev->tasklet_lock, irqflags);
+        tasklet_func = dev->locked_tasklet_func;
+        spin_unlock_irqrestore(&dev->tasklet_lock, irqflags);
 
-        if (!dev->locked_tasklet_func ||
+        if (!tasklet_func ||
             !drm_lock_take(&dev->lock,
                            DRM_KERNEL_CONTEXT)) {
-                spin_unlock_irqrestore(&dev->tasklet_lock, irqflags);
                 return;
         }
 
         dev->lock.lock_time = jiffies;
         atomic_inc(&dev->counts[_DRM_STAT_LOCKS]);
 
-        dev->locked_tasklet_func(dev);
+        spin_lock_irqsave(&dev->tasklet_lock, irqflags);
+        tasklet_func = dev->locked_tasklet_func;
+        dev->locked_tasklet_func = NULL;
+        spin_unlock_irqrestore(&dev->tasklet_lock, irqflags);
+        
+        if (tasklet_func != NULL)
+                tasklet_func(dev);
 
         drm_lock_free(&dev->lock,
                       DRM_KERNEL_CONTEXT);
-
-        dev->locked_tasklet_func = NULL;
-
-        spin_unlock_irqrestore(&dev->tasklet_lock, irqflags);
 }
 
 /**
diff --git a/drivers/gpu/drm/drm_lock.c b/drivers/gpu/drm/drm_lock.c
index 0998723cde79..d78e0dc18245 100644
--- a/drivers/gpu/drm/drm_lock.c
+++ b/drivers/gpu/drm/drm_lock.c
@@ -150,6 +150,7 @@ int drm_unlock(struct drm_device *dev, void *data, struct drm_file *file_priv)
 {
         struct drm_lock *lock = data;
         unsigned long irqflags;
+        void (*tasklet_func)(struct drm_device *);
 
         if (lock->context == DRM_KERNEL_CONTEXT) {
                 DRM_ERROR("Process %d using kernel context %d\n",
@@ -158,14 +159,11 @@ int drm_unlock(struct drm_device *dev, void *data, struct drm_file *file_priv)
         }
 
         spin_lock_irqsave(&dev->tasklet_lock, irqflags);
-
-        if (dev->locked_tasklet_func) {
-                dev->locked_tasklet_func(dev);
-
-                dev->locked_tasklet_func = NULL;
-        }
-
+        tasklet_func = dev->locked_tasklet_func;
+        dev->locked_tasklet_func = NULL;
         spin_unlock_irqrestore(&dev->tasklet_lock, irqflags);
+        if (tasklet_func != NULL)
+                tasklet_func(dev);
 
         atomic_inc(&dev->counts[_DRM_STAT_UNLOCKS]);