[Intel-gfx] [PATCH v2] drm/i915: Check for timeout completion when waiting for the rq to submitted

[Chris Wilson]

We first wait for a request to be submitted to hw and assigned a seqno,
before we can wait for the hw to signal completion (otherwise we don't
know the hw id we need to wait upon). Whilst waiting for the request to
be submitted, we may exceed the user's timeout and need to propagate the
error back.

v2: Make ETIME into an error from wait_for_execute for consistent exit
handling.

Reported-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Fixes: 4680816be336 ("drm/i915: Wait first for submission, before waiting for request completion")
Testcase: igt/gem_wait/basic-await
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: <drm-intel-fixes at lists.freedesktop.org> # v4.10-rc1+
---
 drivers/gpu/drm/i915/i915_gem_request.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
index 72b7f7d9461d..f31deeb72703 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.c
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -1025,8 +1025,13 @@ __i915_request_wait_for_execute(struct drm_i915_gem_request *request,
 			break;
 		}
 
+		if (!timeout) {
+			timeout = -ETIME;
+			break;
+		}
+
 		timeout = io_schedule_timeout(timeout);
-	} while (timeout);
+	} while (1);
 	finish_wait(&request->execute.wait, &wait);
 
 	if (flags & I915_WAIT_LOCKED)
-- 
2.11.0