[PATCH 19/21] drm/i915: Avoid incrementing hangcheck whilst waiting for external fence

[Chris Wilson]

If we are waiting upon an external fence, from the pov of hangcheck the
engine is stuck on the last submitted seqno. Currently we give a small
increment to the hangcheck score in order to catch a stuck waiter /
driver. Now that we both have an independent wait hangcheck and may be
stuck waiting on an external fence, resetting the GPU has little effect
on that external fence. As we cannot advance by resetting, skip
incrementing the hangcheck score.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/i915_irq.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index b76d45d91a84..8462817a7dae 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -3099,10 +3099,6 @@ static void i915_hangcheck_elapsed(struct work_struct *work)
 		if (engine->hangcheck.seqno == seqno) {
 			if (i915_seqno_passed(seqno, submit)) {
 				engine->hangcheck.action = HANGCHECK_IDLE;
-				if (busy) {
-					/* Safeguard against driver failure */
-					engine->hangcheck.score += BUSY;
-				}
 			} else {
 				/* We always increment the hangcheck score
 				 * if the engine is busy and still processing
-- 
2.9.3