gpu: nvgpu: Fix race condition during poweron

When two or more apps ran simultaneously
First app context sets power_on flag & starts init
Other app context check the power_on flag
and try to use GPU without init completed
Which makes aother apps to assert

Added mutex to synchronize poweron access

Bug 200297265

Change-Id: Ie138f7f43bb0dd3304ed91ae3649a6a4947bee91
Signed-off-by: skadamati <skadamati@nvidia.com>
Reviewed-on: https://git-master/r/1511436
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/vgpu/vgpu.c b/drivers/gpu/nvgpu/vgpu/vgpu.c
index f02acad0..bd52dc0a 100644
--- a/drivers/gpu/nvgpu/vgpu/vgpu.c
+++ b/drivers/gpu/nvgpu/vgpu/vgpu.c
@@ -243,6 +243,7 @@ static void vgpu_remove_support(struct gk20a *g)
 
 static void vgpu_init_vars(struct gk20a *g, struct gk20a_platform *platform)
 {
+        nvgpu_mutex_init(&g->poweron_lock);
         nvgpu_mutex_init(&g->poweroff_lock);
         g->regs_saved = g->regs;
         g->bar1_saved = g->bar1;