diff mbox

drm/i915: Reorder semaphore deadlock check

Message ID 1401963909-27142-1-git-send-email-chris@chris-wilson.co.uk (mailing list archive)
State New, archived
Headers show

Commit Message

Chris Wilson June 5, 2014, 10:25 a.m. UTC 
If a semaphore is waiting on another ring, which in turn happens to be
waiting on the first ring, but that second semaphore has been signalled,
we will be able to kick the second ring and so can treat the first ring
as a valid WAIT and not as HUNG.

References: https://bugs.freedesktop.org/show_bug.cgi?id=54226
References: https://bugs.freedesktop.org/show_bug.cgi?id=75502
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
---
 drivers/gpu/drm/i915/i915_irq.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index a702303eab08..41eeeb60c60f 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -2834,7 +2834,7 @@  static int semaphore_passed(struct intel_engine_cs *ring)
 	ring->hangcheck.deadlock = true;
 
 	signaller = semaphore_waits_for(ring, &seqno);
-	if (signaller == NULL || signaller->hangcheck.deadlock)
+	if (signaller == NULL)
 		return -1;
 
 	/* cursory check for an unkickable deadlock */
@@ -2842,7 +2842,13 @@  static int semaphore_passed(struct intel_engine_cs *ring)
 	if (ctl & RING_WAIT_SEMAPHORE && semaphore_passed(signaller) < 0)
 		return -1;
 
-	return i915_seqno_passed(signaller->get_seqno(signaller, false), seqno);
+	if (i915_seqno_passed(signaller->get_seqno(signaller, false), seqno))
+		return 1;
+
+	if (signaller->hangcheck.deadlock)
+		return -1;
+
+	return 0;
 }
 
 static void semaphore_clear_deadlocks(struct drm_i915_private *dev_priv)