gpu: nvgpu: handle pm suspend/resume with runtime pm disable

When runtime pm is disabled, then gpu rail will be on as soon as
nvgpu module is loaded. If pm suspend/resume called before gpu
hw initialization(g->poweron = false) then pm suspend is skipping
gpu railgate, which is causing issues with SC7 entry/exit.
To fix this issue:
1. During pm suspend, if g->poweron is false, check for runtime pm
   disable to railgate gpu rail.
2. On pm resume, check for runtime pm disable to enable gpu rail,
   though gpu driver not initialized.

Bug 2073029

Change-Id: I7631109d79cda5882d2864557f1b7b3d2d89c9f6
Signed-off-by: seshendra Gadagottu <sgadagottu@nvidia.com>
Signed-off-by: Seema Khowala <seemaj@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1679010
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/gpu/nvgpu/common/linux/module.c b/drivers/gpu/nvgpu/common/linux/module.c
index cebb5565..b9c9554b 100644
--- a/drivers/gpu/nvgpu/common/linux/module.c
+++ b/drivers/gpu/nvgpu/common/linux/module.c
@@ -960,8 +960,11 @@ static int gk20a_pm_suspend(struct device *dev)
         int ret = 0;
         int idle_usage_count = g->user_railgate_disabled ? 1 : 0;
 
-        if (!g->power_on)
+        if (!g->power_on) {
+                if (!pm_runtime_enabled(dev))
+                        gk20a_pm_railgate(dev);
                 return 0;
+        }
 
         if (nvgpu_atomic_read(&g->usage_count) > idle_usage_count)
                 return -EBUSY;
@@ -983,8 +986,11 @@ static int gk20a_pm_resume(struct device *dev)
         struct gk20a *g = get_gk20a(dev);
         int ret = 0;
 
-        if (!g->suspended)
+        if (!g->suspended) {
+                if (!pm_runtime_enabled(dev))
+                        gk20a_pm_unrailgate(dev);
                 return 0;
+        }
 
         ret = gk20a_pm_runtime_resume(dev);