gpu: nvgpu: Fix error handling of __semaphore_bitmap_alloc()

The return from __semaphore_bitmap_alloc() is an int for which a
negative value indicates a failure. That return value was being
directly cast to an unsigned int before being checked for a
negative error code. This obviously isn't a good idea.

Coverity ID 38754

Change-Id: I50c0478e5504988b059e69b929e9c2e465df7cc0
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: http://git-master/r/1210317
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/semaphore_gk20a.c b/drivers/gpu/nvgpu/gk20a/semaphore_gk20a.c
index 0fa31468..2038e300 100644
--- a/drivers/gpu/nvgpu/gk20a/semaphore_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/semaphore_gk20a.c
@@ -122,7 +122,7 @@ struct gk20a_semaphore_pool *gk20a_semaphore_pool_alloc(
 {
         struct gk20a_semaphore_pool *p;
         unsigned long page_idx;
-        int err = 0;
+        int ret, err = 0;
 
         p = kzalloc(sizeof(*p), GFP_KERNEL);
         if (!p)
@@ -130,13 +130,14 @@ struct gk20a_semaphore_pool *gk20a_semaphore_pool_alloc(
 
         __lock_sema_sea(sea);
 
-        page_idx = __semaphore_bitmap_alloc(sea->pools_alloced,
-                                            SEMAPHORE_POOL_COUNT);
-        if (page_idx < 0) {
-                err = page_idx;
+        ret = __semaphore_bitmap_alloc(sea->pools_alloced, SEMAPHORE_POOL_COUNT);
+        if (ret < 0) {
+                err = ret;
                 goto fail;
         }
 
+        page_idx = (unsigned long)ret;
+
         p->page = sea->sea_mem.pages[page_idx];
         p->ro_sg_table = sea->ro_sg_table;
         p->page_idx = page_idx;