gpu: nvgpu: add error prints for do_idle() failure

Add error prints in gk20a_do_idle() to narrow down
the failure point

Bug 200064302

Change-Id: Iffe1151bdc200a79b88e273b3b01523f8e46d130
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/664446
(cherry picked from commit bf1cd9b5551d27cb5cc468795cd147376f48e482)
Reviewed-on: http://git-master/r/666218
Reviewed-by: Sachin Nikam <snikam@nvidia.com>

1 files changed, 8 insertions, 3 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.c b/drivers/gpu/nvgpu/gk20a/gk20a.c
index 2b8276e3..a13d54b3 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.c
@@ -1654,8 +1654,11 @@ int __gk20a_do_idle(struct platform_device *pdev)
                 ref_cnt = atomic_read(&pdev->dev.power.usage_count);
         } while (ref_cnt != 1 && time_before(jiffies, timeout));
 
-        if (ref_cnt != 1)
+        if (ref_cnt != 1) {
+                gk20a_err(&pdev->dev, "failed to idle - refcount %d != 1\n",
+                        ref_cnt);
                 goto fail;
+        }
 
         /*
          * if GPU is now idle, we will have only one ref count
@@ -1678,10 +1681,12 @@ int __gk20a_do_idle(struct platform_device *pdev)
                         is_railgated = platform->is_railgated(pdev);
                 } while (!is_railgated && time_before(jiffies, timeout));
 
-                if (is_railgated)
+                if (is_railgated) {
                         return 0;
-                else
+                } else {
+                        gk20a_err(&pdev->dev, "failed to idle in timeout\n");
                         goto fail_timeout;
+                }
         } else {
                 if (!platform->reset_assert || !platform->reset_deassert)
                         goto fail_timeout;