drm/i915/selftests: Check for the error interrupt before we wait!

Sometimes the error interrupt can fire even before we have seen the
request go active -- in which case, we end up waiting until the timeout
as the request is already completed. Double check for this case!

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200214120659.3888735-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
index 3a74a54739a8d30656abb8917b9a280321530832..64761e6198767abd4304ec121233e5780b295702 100644 (file)
--- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
+++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
@@ -76,11 +76,15 @@ static int wait_for_submit(struct intel_engine_cs *engine,
        do {
                cond_resched();
                intel_engine_flush_submission(engine);
+
                if (i915_request_is_active(rq) &&
                    !READ_ONCE(engine->execlists.pending[0])) {
                        tasklet_unlock_wait(&engine->execlists.tasklet);
                        return 0;
                }
+
+               if (i915_request_completed(rq)) /* that was quick! */
+                       return 0;
        } while (time_before(jiffies, timeout));
 
        return -ETIME;