gpu: nvgpu: add __must_check to gk20a_busy

The return value of gk20a_busy must be checked since it may not succeed
in some cases. Add the __must_check attribute that generates a compiler
warning for code that does not read the return value and fix all uses of
the function to take error cases into account.

Bug 200040921

Change-Id: Ibc2b119985fa230324c88026fe94fc5f1894fe4f
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: http://git-master/r/542552
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c b/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c
index 40751b88..6af54e68 100644
--- a/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c
@@ -571,7 +571,10 @@ static int dbg_set_powergate(struct dbg_session_gk20a *dbg_s,
                     (g->dbg_powergating_disabled_refcount++ == 0)) {
 
                         gk20a_dbg(gpu_dbg_gpu_dbg | gpu_dbg_fn, "module busy");
-                        gk20a_busy(g->dev);
+                        err = gk20a_busy(g->dev);
+                        if (err)
+                                return err;
+
                         err = gk20a_busy(dbg_s->pdev);
                         if (err)
                                 return -EPERM;