1 files changed, 9 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 8f7baad72316..1a7dc7754e2f 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1200,15 +1200,19 @@ static void display_pipe_crc_irq_handler(struct drm_device *dev, enum pipe pipe,
         struct intel_pipe_crc_entry *entry;
         int head, tail;
 
+        spin_lock(&pipe_crc->lock);
+
         if (!pipe_crc->entries) {
+                spin_unlock(&pipe_crc->lock);
                 DRM_ERROR("spurious interrupt\n");
                 return;
         }
 
-        head = atomic_read(&pipe_crc->head);
-        tail = atomic_read(&pipe_crc->tail);
+        head = pipe_crc->head;
+        tail = pipe_crc->tail;
 
         if (CIRC_SPACE(head, tail, INTEL_PIPE_CRC_ENTRIES_NR) < 1) {
+                spin_unlock(&pipe_crc->lock);
                 DRM_ERROR("CRC buffer overflowing\n");
                 return;
         }
@@ -1223,7 +1227,9 @@ static void display_pipe_crc_irq_handler(struct drm_device *dev, enum pipe pipe,
         entry->crc[4] = crc4;
 
         head = (head + 1) & (INTEL_PIPE_CRC_ENTRIES_NR - 1);
-        atomic_set(&pipe_crc->head, head);
+        pipe_crc->head = head;
+
+        spin_unlock(&pipe_crc->lock);
 
         wake_up_interruptible(&pipe_crc->wq);
 }