drm: Make locked tasklet handling more robust.

Initialize the spinlock unconditionally when struct drm_device is filled in,
and return early in drm_locked_tasklet() if the driver doesn't support IRQs.

Signed-off-by: Dave Airlie <airlied@linux.ie>

2 files changed, 3 insertions, 2 deletions

diff --git a/drivers/char/drm/drm_irq.c b/drivers/char/drm/drm_irq.c
index 2b10e5b60cfa..b08608a9f026 100644
--- a/drivers/char/drm/drm_irq.c
+++ b/drivers/char/drm/drm_irq.c
@@ -119,7 +119,6 @@ static int drm_irq_install(drm_device_t * dev)
                 init_waitqueue_head(&dev->vbl_queue);
 
                 spin_lock_init(&dev->vbl_lock);
-                spin_lock_init(&dev->tasklet_lock);
 
                 INIT_LIST_HEAD(&dev->vbl_sigs.head);
                 INIT_LIST_HEAD(&dev->vbl_sigs2.head);
@@ -456,7 +455,8 @@ void drm_locked_tasklet(drm_device_t *dev, void (*func)(drm_device_t*))
         unsigned long irqflags;
         static DECLARE_TASKLET(drm_tasklet, drm_locked_tasklet_func, 0);
 
-        if (test_bit(TASKLET_STATE_SCHED, &drm_tasklet.state))
+        if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ) ||
+            test_bit(TASKLET_STATE_SCHED, &drm_tasklet.state))
                 return;
 
         spin_lock_irqsave(&dev->tasklet_lock, irqflags);
diff --git a/drivers/char/drm/drm_stub.c b/drivers/char/drm/drm_stub.c
index 6f748e194cf9..5fd6dc0870cf 100644
--- a/drivers/char/drm/drm_stub.c
+++ b/drivers/char/drm/drm_stub.c
@@ -61,6 +61,7 @@ static int drm_fill_in_dev(drm_device_t * dev, struct pci_dev *pdev,
 
         spin_lock_init(&dev->count_lock);
         spin_lock_init(&dev->drw_lock);
+        spin_lock_init(&dev->tasklet_lock);
         init_timer(&dev->timer);
         mutex_init(&dev->struct_mutex);
         mutex_init(&dev->ctxlist_mutex);