drm/i915/ringbuffer: Make IRQ refcnting atomic
In order to enforce the correct memory barriers for irq get/put, we need
to perform the actual counting using atomic operations.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 27fa2a1..726c2cc 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2000,17 +2000,19 @@
trace_i915_gem_request_wait_begin(dev, seqno);
ring->waiting_seqno = seqno;
- ring->irq_get(ring);
- if (interruptible)
- ret = wait_event_interruptible(ring->irq_queue,
- i915_seqno_passed(ring->get_seqno(ring), seqno)
- || atomic_read(&dev_priv->mm.wedged));
- else
- wait_event(ring->irq_queue,
- i915_seqno_passed(ring->get_seqno(ring), seqno)
- || atomic_read(&dev_priv->mm.wedged));
+ ret = -ENODEV;
+ if (ring->irq_get(ring)) {
+ if (interruptible)
+ ret = wait_event_interruptible(ring->irq_queue,
+ i915_seqno_passed(ring->get_seqno(ring), seqno)
+ || atomic_read(&dev_priv->mm.wedged));
+ else
+ wait_event(ring->irq_queue,
+ i915_seqno_passed(ring->get_seqno(ring), seqno)
+ || atomic_read(&dev_priv->mm.wedged));
- ring->irq_put(ring);
+ ring->irq_put(ring);
+ }
ring->waiting_seqno = 0;
trace_i915_gem_request_wait_end(dev, seqno);
@@ -3157,14 +3159,15 @@
* generation is designed to be run atomically and so is
* lockless.
*/
- ring->irq_get(ring);
- ret = wait_event_interruptible(ring->irq_queue,
- i915_seqno_passed(ring->get_seqno(ring), seqno)
- || atomic_read(&dev_priv->mm.wedged));
- ring->irq_put(ring);
+ if (ring->irq_get(ring)) {
+ ret = wait_event_interruptible(ring->irq_queue,
+ i915_seqno_passed(ring->get_seqno(ring), seqno)
+ || atomic_read(&dev_priv->mm.wedged));
+ ring->irq_put(ring);
- if (ret == 0 && atomic_read(&dev_priv->mm.wedged))
- ret = -EIO;
+ if (ret == 0 && atomic_read(&dev_priv->mm.wedged))
+ ret = -EIO;
+ }
}
if (ret == 0)