[PATCH 5.16 081/126] drm/i915: Lock timeline mutex directly in error path of eb_pin_timeline

[Greg Kroah-Hartman]

From: Matthew Brost <matthew.brost@xxxxxxxxx>

commit 5ae13c305ef8cb54efc4f0ba4565709b9f320fed upstream.

Don't use the interruptable version of the timeline mutex lock in the
error path of eb_pin_timeline as the cleanup must always happen.

v2:
 (John Harrison)
  - Don't check for interrupt during mutex lock
v3:
 (Tvrtko)
  - A comment explaining why lock helper isn't used

Fixes: 544460c33821 ("drm/i915: Multi-BB execbuf")
Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
Reviewed-by: John Harrison <John.C.Harrison@xxxxxxxxx>
Signed-off-by: John Harrison <John.C.Harrison@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20220111163929.14017-1-matthew.brost@xxxxxxxxx
(cherry picked from commit cb935c4618bd2ff9058feee4af7088446da6a763)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -2372,9 +2372,14 @@ static int eb_pin_timeline(struct i915_e
 				      timeout) < 0) {
 			i915_request_put(rq);
 
-			tl = intel_context_timeline_lock(ce);
+			/*
+			 * Error path, cannot use intel_context_timeline_lock as
+			 * that is user interruptable and this clean up step
+			 * must be done.
+			 */
+			mutex_lock(&ce->timeline->mutex);
 			intel_context_exit(ce);
-			intel_context_timeline_unlock(tl);
+			mutex_unlock(&ce->timeline->mutex);
 
 			if (nonblock)
 				return -EWOULDBLOCK;