[PATCH] drm/i915: Fix wrong return value

[PATCH] drm/i915: Fix wrong return value

[Tianjia Zhang]

In function i915_active_acquire_preallocate_barrier(), not all
paths have the return value set correctly, and in case of memory
allocation failure, a negative error code should be returned.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
---
 drivers/gpu/drm/i915/i915_active.c            | 4 ++--
 drivers/gpu/drm/i915/selftests/i915_request.c | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c
index d960d0be5bd2..cc017e3cc9c5 100644
--- a/drivers/gpu/drm/i915/i915_active.c
+++ b/drivers/gpu/drm/i915/i915_active.c
@@ -758,7 +758,7 @@ int i915_active_acquire_preallocate_barrier(struct i915_active *ref,
 	intel_engine_mask_t tmp, mask = engine->mask;
 	struct llist_node *first = NULL, *last = NULL;
 	struct intel_gt *gt = engine->gt;
-	int err;
+	int err = 0;
 
 	GEM_BUG_ON(i915_active_is_idle(ref));
 
@@ -782,7 +782,7 @@ int i915_active_acquire_preallocate_barrier(struct i915_active *ref,
 		if (!node) {
 			node = kmem_cache_alloc(global.slab_cache, GFP_KERNEL);
 			if (!node) {
-				err = ENOMEM;
+				err = -ENOMEM;
 				goto unwind;
 			}
 
diff --git a/drivers/gpu/drm/i915/selftests/i915_request.c b/drivers/gpu/drm/i915/selftests/i915_request.c
index 6014e8dfcbb1..dda801a87b8a 100644
--- a/drivers/gpu/drm/i915/selftests/i915_request.c
+++ b/drivers/gpu/drm/i915/selftests/i915_request.c
@@ -326,7 +326,7 @@ static int __igt_breadcrumbs_smoketest(void *arg)
 		if (!wait) {
 			i915_sw_fence_commit(submit);
 			heap_fence_put(submit);
-			err = ENOMEM;
+			err = -ENOMEM;
 			break;
 		}
 
-- 
2.26.2

Re: [PATCH] drm/i915: Fix wrong return value

[Andi Shyti]

Hi Tianjia,

> diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c
> index d960d0be5bd2..cc017e3cc9c5 100644
> --- a/drivers/gpu/drm/i915/i915_active.c
> +++ b/drivers/gpu/drm/i915/i915_active.c
> @@ -758,7 +758,7 @@ int i915_active_acquire_preallocate_barrier(struct i915_active *ref,
>  	intel_engine_mask_t tmp, mask = engine->mask;
>  	struct llist_node *first = NULL, *last = NULL;
>  	struct intel_gt *gt = engine->gt;
> -	int err;
> +	int err = 0;

you don't need the initialization here.

Thanks,
Andi

Re: [Intel-gfx] [PATCH] drm/i915: Fix wrong return value

[Chris Wilson]

Quoting Andi Shyti (2020-08-02 12:40:44)
> Hi Tianjia,
> 
> > diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c
> > index d960d0be5bd2..cc017e3cc9c5 100644
> > --- a/drivers/gpu/drm/i915/i915_active.c
> > +++ b/drivers/gpu/drm/i915/i915_active.c
> > @@ -758,7 +758,7 @@ int i915_active_acquire_preallocate_barrier(struct i915_active *ref,
> >       intel_engine_mask_t tmp, mask = engine->mask;
> >       struct llist_node *first = NULL, *last = NULL;
> >       struct intel_gt *gt = engine->gt;
> > -     int err;
> > +     int err = 0;
> 
> you don't need the initialization here.

But it's close enough that I can munge the patch inline.
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
-Chris

Re: [Intel-gfx] [PATCH] drm/i915: Fix wrong return value

[Andi Shyti]

> > > diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c
> > > index d960d0be5bd2..cc017e3cc9c5 100644
> > > --- a/drivers/gpu/drm/i915/i915_active.c
> > > +++ b/drivers/gpu/drm/i915/i915_active.c
> > > @@ -758,7 +758,7 @@ int i915_active_acquire_preallocate_barrier(struct i915_active *ref,
> > >       intel_engine_mask_t tmp, mask = engine->mask;
> > >       struct llist_node *first = NULL, *last = NULL;
> > >       struct intel_gt *gt = engine->gt;
> > > -     int err;
> > > +     int err = 0;
> > 
> > you don't need the initialization here.
> 
> But it's close enough that I can munge the patch inline.
> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

sure... you can also remove it before merging it and it might
also need:

Fixes: d8af05ff38ae7 ("drm/i915: Allow sharing the idle-barrier from other kernel requests)

but, yeah...

Reviewed-by: Andi Shyti <andi.shyti@intel.com>

... as well :)

Andi