drm/i915: Propagate errors from writing to ringbuffer
Preparing the ringbuffer for adding new commands can fail (a timeout
whilst waiting for the GPU to catch up and free some space). So check
for any potential error before overwriting HEAD with new commands, and
propagate that error back to the user where possible.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 852a2d84..8acdd6d 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1101,12 +1101,13 @@
if (master_priv->sarea_priv)
master_priv->sarea_priv->last_enqueue = dev_priv->counter;
- BEGIN_LP_RING(4);
- OUT_RING(MI_STORE_DWORD_INDEX);
- OUT_RING(I915_BREADCRUMB_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
- OUT_RING(dev_priv->counter);
- OUT_RING(MI_USER_INTERRUPT);
- ADVANCE_LP_RING();
+ if (BEGIN_LP_RING(4) == 0) {
+ OUT_RING(MI_STORE_DWORD_INDEX);
+ OUT_RING(I915_BREADCRUMB_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
+ OUT_RING(dev_priv->counter);
+ OUT_RING(MI_USER_INTERRUPT);
+ ADVANCE_LP_RING();
+ }
return dev_priv->counter;
}