Am 02.10.2018 um 08:41 schrieb Nathan Chancellor:

Clang generates a warning when it sees a logical not followed by a conditional operator like ==, >, or <.

drivers/gpu/drm/scheduler/sched_entity.c:470:6: warning: logical not is only applied to the left hand side of this comparison [-Wlogical-not-parentheses] if (!spsc_queue_count(&entity->job_queue) == 0 || ^ ~~ drivers/gpu/drm/scheduler/sched_entity.c:470:6: note: add parentheses after the '!' to evaluate the comparison first if (!spsc_queue_count(&entity->job_queue) == 0 || ^ ( ) drivers/gpu/drm/scheduler/sched_entity.c:470:6: note: add parentheses around left hand side expression to silence this warning if (!spsc_queue_count(&entity->job_queue) == 0 || ^ ( ) 1 warning generated.

It assumes the author might have made a mistake in their logic:

if (!a == b) -> if (!(a == b))

Sometimes that is the case; other times, it's just a super convoluted way of saying 'if (a)' when b = 0:

if (!1 == 0) -> if (0 == 0) -> if (true)

Alternatively:

if (!1 == 0) -> if (!!1) -> if (1)

Simplify this comparison so that Clang doesn't complain.

Fixes: 35e160e781a0 ("drm/scheduler: change entities rq even earlier") Signed-off-by: Nathan Chancellor natechancellor@gmail.com

Reviewed-by: Christian König christian.koenig@amd.com

Going to pick that up for pushing upstream as well.

Thanks, Christian.

---

drivers/gpu/drm/scheduler/sched_entity.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 4e5e95c0cab5..3e22a54a99c2 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -467,8 +467,7 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity) struct dma_fence *fence; struct drm_sched_rq *rq;

• if (!spsc_queue_count(&entity->job_queue) == 0 ||

•    entity->num_rq_list <= 1)
  

• if (spsc_queue_count(&entity->job_queue) || entity->num_rq_list <= 1) return;

  fence = READ_ONCE(entity->last_scheduled);