[Intel-gfx] [CI] drm/i915: Report if i915_active is still busy upon waiting

[Chris Wilson]

If we try to wait on an i915_active from within a critical section, it
will remain busy (such as if we are shrinking from within
i915_active_ref). Report the failure so that we do not proceed thinking
it is idle.

Extracted from a future patch "drm/i915: Coordinate i915_active with its
own mutex".

Fixes: 12c255b5dad1 ("drm/i915: Provide an i915_active.acquire callback")
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld at intel.com>
Reviewed-by: Matthew Auld <matthew.auld at intel.com>
---
 drivers/gpu/drm/i915/i915_active.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c
index cb6a1eadf7df..584b247df9bc 100644
--- a/drivers/gpu/drm/i915/i915_active.c
+++ b/drivers/gpu/drm/i915/i915_active.c
@@ -287,7 +287,13 @@ int i915_active_wait(struct i915_active *ref)
 	}
 
 	__active_retire(ref);
-	return err;
+	if (err)
+		return err;
+
+	if (!i915_active_is_idle(ref))
+		return -EBUSY;
+
+	return 0;
 }
 
 int i915_request_await_active_request(struct i915_request *rq,
-- 
2.20.1