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/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 9652e46..8e2e357 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -54,8 +54,8 @@
u32 irq_seqno; /* last seq seem at irq time */
u32 waiting_seqno;
u32 sync_seqno[I915_NUM_RINGS-1];
- u32 irq_refcount;
- void (*irq_get)(struct intel_ring_buffer *ring);
+ atomic_t irq_refcount;
+ bool __must_check (*irq_get)(struct intel_ring_buffer *ring);
void (*irq_put)(struct intel_ring_buffer *ring);
int (*init)(struct intel_ring_buffer *ring);