gpu: nvgpu: use single lock for gpu power on-off

Using two separate locks (poweron_lock and poweroff_lock)
allows concurrent gpu power-on and power-off. This shall
not happen as driver won't be able to maintain correct
gpu state.

Use a single power_lock to manage gpu power state. This
lock will be used to manage gpu power state from multiple
triggers like gpu idle, gpu gc-off, etc.

JIRA NVGPU-1100

Change-Id: Ia9b4aeda024a5844ae9f182d453cd6341876680a
Signed-off-by: Nitin Kumbhar <nkumbhar@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1827812
Reviewed-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-by: svc-misra-checker <svc-misra-checker@nvidia.com>
Reviewed-by: Debarshi Dutta <ddutta@nvidia.com>
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 15 insertions, 7 deletions

diff --git a/drivers/gpu/nvgpu/os/linux/vgpu/vgpu_linux.c b/drivers/gpu/nvgpu/os/linux/vgpu/vgpu_linux.c
index 3fd944f4..7cf22d9d 100644
--- a/drivers/gpu/nvgpu/os/linux/vgpu/vgpu_linux.c
+++ b/drivers/gpu/nvgpu/os/linux/vgpu/vgpu_linux.c
@@ -72,8 +72,7 @@ static void vgpu_init_vars(struct gk20a *g, struct gk20a_platform *platform)
 {
         struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
 
-        nvgpu_mutex_init(&g->poweron_lock);
-        nvgpu_mutex_init(&g->poweroff_lock);
+        nvgpu_mutex_init(&g->power_lock);
         nvgpu_mutex_init(&g->ctxsw_disable_lock);
         l->regs_saved = l->regs;
         l->bar1_saved = l->bar1;
@@ -142,16 +141,19 @@ int vgpu_pm_prepare_poweroff(struct device *dev)
 
         nvgpu_log_fn(g, " ");
 
+        nvgpu_mutex_acquire(&g->power_lock);
+
         if (!g->power_on)
-                return 0;
+                goto done;
 
         if (g->ops.fifo.channel_suspend)
                 ret = g->ops.fifo.channel_suspend(g);
-
         if (ret)
-                return ret;
+                goto done;
 
         g->power_on = false;
+ done:
+        nvgpu_mutex_release(&g->power_lock);
 
         return ret;
 }
@@ -160,12 +162,14 @@ int vgpu_pm_finalize_poweron(struct device *dev)
 {
         struct gk20a *g = get_gk20a(dev);
         struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
-        int err;
+        int err = 0;
 
         nvgpu_log_fn(g, " ");
 
+        nvgpu_mutex_acquire(&g->power_lock);
+
         if (g->power_on)
-                return 0;
+                goto done;
 
         g->power_on = true;
 
@@ -220,6 +224,10 @@ int vgpu_pm_finalize_poweron(struct device *dev)
         g->sw_ready = true;
 
 done:
+        if (err)
+                g->power_on = false;
+
+        nvgpu_mutex_release(&g->power_lock);
         return err;
 }