gpu: nvgpu: BUG_ON for sema increment, not value

When adding a sema wait to a pushbuf, verify that the sema threshold has
been incremented from the original value by reading the incremented
field instead of value (which is set to nonzero by
nvgpu_semaphore_incr()). Value could be 0 even after an increment if new
semas weren't reset to 0.

Jira NVGPU-514

Change-Id: I295451fbc7eb9e597aea12d73074e99f74a6a899
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1658100
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c b/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c
index 9649c573..85c55955 100644
--- a/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c
@@ -625,7 +625,7 @@ static int __semaphore_wait_fd_fast_path(struct channel_gk20a *c,
                 return err;
 
         nvgpu_semaphore_get(sema);
-        BUG_ON(!nvgpu_atomic_read(&sema->value));
+        BUG_ON(!sema->incremented);
         add_sema_cmd(c->g, c, sema, wait_cmd, 8, true, false);
 
         /*