[PATCH 6.0 097/124] drm/i915: Never return 0 if not all requests retired

Greg Kroah-Hartman
2022-12-05T19:28:22Z

From: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>

commit 12b8b046e4c9de40fa59b6f067d6826f4e688f68 upstream.

Users of intel_gt_retire_requests_timeout() expect 0 return value on
success. However, we have no protection from passing back 0 potentially
returned by a call to dma_fence_wait_timeout() when it succedes right
after its timeout has expired.

Replace 0 with -ETIME before potentially using the timeout value as return
code, so -ETIME is returned if there are still some requests not retired
after timeout, 0 otherwise.

v3: Use conditional expression, more compact but also better reflecting
intention standing behind the change.

v2: Move the added lines down so flush_submission() is not affected.

Fixes: f33a8a51602c ("drm/i915: Merge wait_for_timelines with retire_request")
Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: stable@vger.kernel.org # v5.5+
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221121145655.75141-3-janusz.krzysztofik@linux.intel.com
(cherry picked from commit f301a29f143760ce8d3d6b6a8436d45d3448cde6)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/i915/gt/intel_gt_requests.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/i915/gt/intel_gt_requests.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt_requests.c
@@ -199,7 +199,7 @@ out_active: spin_lock(&timelines->lock);
if (remaining_timeout)
*remaining_timeout = timeout;

- return active_count ? timeout : 0;
+ return active_count ? timeout ?: -ETIME : 0;
}

static void retire_work_handler(struct work_struct *work)