[Intel-gfx] [PATCH 3/4] drm/i915: Clear hangcheck score if engine is idle

[Mika Kuoppala]

If we have accumulated hangcheck score before reaching
engine idle, that score will remain and is transferred to
the next set of batches. This is wrong as idle is a quite clear
boundary to prevent hangcheck score manipulation across batches.

Fix this by clearing the score if engine reaches idle.

Cc: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/i915_irq.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 3507269..c1d1400 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -3091,6 +3091,9 @@ static void i915_hangcheck_elapsed(struct work_struct *work)
 			ring->hangcheck.acthd = ring->hangcheck.max_acthd = 0;
 		}
 
+		if (!busy)
+			ring->hangcheck.score = 0;
+
 		ring->hangcheck.seqno = seqno;
 		ring->hangcheck.acthd = acthd;
 		busy_count += busy;
-- 
2.5.0