[PATCH 2/3] drm/i915: Never return 0 on timeout when retiring requests

[Janusz Krzysztofik]

Users expect 0 return value on success.  However, we have no protection
from passing back 0 potentially returned by dma_fence_wait_timeout() on
timeout.

Replace 0 with -ETIME before using timeout as return value.

Fixes: f33a8a51602c ("drm/i915: Merge wait_for_timelines with retire_request")
Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik at linux.intel.com>
Cc: stable at vger.kernel.org # v5.5+
---
 drivers/gpu/drm/i915/gt/intel_gt_requests.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/intel_gt_requests.c b/drivers/gpu/drm/i915/gt/intel_gt_requests.c
index ae994c2b7a29a..8e857cf4f45ad 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_requests.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt_requests.c
@@ -215,6 +215,9 @@ out_active:	spin_lock(&timelines->lock);
 	list_for_each_entry_safe(tl, tn, &free, link)
 		__intel_timeline_free(&tl->kref);
 
+	if (!timeout)
+		timeout = -ETIME;
+
 	if (flush_submission(gt, timeout)) /* Wait, there's more! */
 		active_count++;
 
-- 
2.25.1