| Message ID | 20181002064124.25881-1-natechancellor@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/scheduler: Simplify spsc_queue_count check in drm_sched_entity_select_rq | expand |
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);
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);
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> --- drivers/gpu/drm/scheduler/sched_entity.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)