[Intel-gfx] [PATCH 5/5] drm/i915: non-interruptible sleeps can't handle -EGAIN

[Daniel Vetter]

So don't return -EAGAIN, even in the case of a gpu hang. Remap it to -EIO
instead.

This is a bit ugly because intel_ring_begin is all non-interruptible
and hence only returns -EIO. But as the comment in there says,
auditing all the callsites would be a pain.

To avoid duplicating code, reuse i915_gem_check_wedge in __wait_seqno.
Use the opportunity to clarify the different cases a bit with
comments.

Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/i915/i915_gem.c |   17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 1214850..32b4db3 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1878,7 +1878,16 @@ i915_gem_check_wedge(struct drm_i915_private *dev_priv)
 		recovery_complete = x->done > 0;
 		spin_unlock_irqrestore(&x->wait.lock, flags);
 
-		return recovery_complete ? -EIO : -EAGAIN;
+		/* Non-interruptible callers can't handle -EAGAIN, hence return
+		 * -EIO unconditionally for these. */
+		if (!dev_priv->mm.interruptible)
+			return -EIO;
+
+		/* Recovery complete, but still wedged means reset failure. */
+		if (recovery_complete)
+			return -EIO;
+
+		return -EAGAIN;
 	}
 
 	return 0;
@@ -1932,6 +1941,7 @@ static int __wait_seqno(struct intel_ring_buffer *ring, u32 seqno,
 	unsigned long timeout_jiffies;
 	long end;
 	bool wait_forever = true;
+	int ret;
 
 	if (i915_seqno_passed(ring->get_seqno(ring), seqno))
 		return 0;
@@ -1963,8 +1973,9 @@ static int __wait_seqno(struct intel_ring_buffer *ring, u32 seqno,
 			end = wait_event_timeout(ring->irq_queue, EXIT_COND,
 						 timeout_jiffies);
 
-		if (atomic_read(&dev_priv->mm.wedged))
-			end = -EAGAIN;
+		ret = i915_gem_check_wedge(dev_priv);
+		if (ret)
+			end = ret;
 	} while (end == 0 && wait_forever);
 
 	getrawmonotonic(&now);
-- 
1.7.10