gpu: nvgpu: check that GPU is powered before flush

if GPU is not powered before L2 is flushed, then
L2 cache flush is a noop. Same behavior as
gk20a_mm_L2_Invalidate()

bug 1661228

Change-Id: I0f590628928a73b7277d1b16a5a79a86e0213648
Signed-off-by: Sam Payne <spayne@nvidia.com>
Reviewed-on: http://git-master/r/768068
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-by: Sachin Nikam <snikam@nvidia.com>
(cherry picked from commit cb4d29d34d0736aa753afa323bfb216481cc8640)
Reviewed-on: http://git-master/r/771113
GVS: Gerrit_Virtual_Submit

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
index 112e218a..1e0fd6af 100644
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
@@ -3225,6 +3225,12 @@ int gk20a_mm_fb_flush(struct gk20a *g)
 
         gk20a_dbg_fn("");
 
+        gk20a_busy_noresume(g->dev);
+        if (!g->power_on) {
+                pm_runtime_put_noidle(&g->dev->dev);
+                return 0;
+        }
+
         mutex_lock(&mm->l2_op_lock);
 
         /* Make sure all previous writes are committed to the L2. There's no
@@ -3262,6 +3268,8 @@ int gk20a_mm_fb_flush(struct gk20a *g)
 
         mutex_unlock(&mm->l2_op_lock);
 
+        pm_runtime_put_noidle(&g->dev->dev);
+
         return ret;
 }