gpu: nvgpu: skip taking g->busy_lock in gk20a_idle

We use g->busy_lock in gk20a_do_idle() to prevent submitting
more jobs to h/w and to wait for currently running jobs to
finish

But requesting this lock in gk20a_idle() prevents decrementing
runtime counter and hence gk20a_do_idle() can timeout with
below prints
[  148.904739] gk20a 17000000.gp10b: Timeout detected @
gk20a_do_idle+0x30/0x38
[  148.912185] gk20a 17000000.gp10b: __gk20a_do_idle: failed to idle -
refcount 4 != 1

Hence skip requesting this lock in gk20a_idle()

Bug 200294536

Change-Id: I060075fdee1b68e1b5fa11baa44a3f5ce4917d94
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/1480756
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 1 insertions, 4 deletions

diff --git a/drivers/gpu/nvgpu/common/linux/module.c b/drivers/gpu/nvgpu/common/linux/module.c
index 708190f2..72719297 100644
--- a/drivers/gpu/nvgpu/common/linux/module.c
+++ b/drivers/gpu/nvgpu/common/linux/module.c
@@ -109,12 +109,11 @@ void gk20a_idle(struct gk20a *g)
         struct device *dev;
 
         atomic_dec(&g->usage_count);
-        down_read(&g->busy_lock);
 
         dev = g->dev;
 
         if (!(dev && gk20a_can_busy(g)))
-                goto fail;
+                return;
 
         if (pm_runtime_enabled(dev)) {
 #ifdef CONFIG_PM
@@ -128,8 +127,6 @@ void gk20a_idle(struct gk20a *g)
         } else {
                 gk20a_scale_notify_idle(dev);
         }
-fail:
-        up_read(&g->busy_lock);
 }
 
 int gk20a_pm_finalize_poweron(struct device *dev)