gpu: nvgpu: skip suspend if gpu already removed

On nvgpu module unload, platform_driver_unregister() detaches
driver from device (driver_detach()). As part of this,
__device_release_driver() results a race between driver's
.runtime_resume(), .remove() and .runtime_suspend().

As nvgpu's .remove() is handling all steps of cleaning up
driver state and shutting down gpu, .runtime_suspend()
shall have no work. So skip .runtime_suspend() is gk20a *g
has already been processed.

Bug 1987855

Change-Id: I024ac63d321689ea04c64b1ffc125da943d482f9
Signed-off-by: Nitin Kumbhar <nkumbhar@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1770803
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Seshendra Gadagottu <sgadagottu@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/os/linux/module.c b/drivers/gpu/nvgpu/os/linux/module.c
index 28ade90f..a59ac1f1 100644
--- a/drivers/gpu/nvgpu/os/linux/module.c
+++ b/drivers/gpu/nvgpu/os/linux/module.c
@@ -936,6 +936,9 @@ static int gk20a_pm_runtime_suspend(struct device *dev)
         int err = 0;
         struct gk20a *g = get_gk20a(dev);
 
+        if (!g)
+                return 0;
+
         if (gk20a_gpu_is_virtual(dev))
                 err = vgpu_pm_prepare_poweroff(dev);
         else