gpu: nvpgu: unpowergate GPU in ioctl_tsg_open()

The nvgpu_ioctl_tsg_open() does not make sure that GPU is
unpowergated. Due to this it leads to kernel
panic when GPU registers are accessed when powergated.

__gk20a_warn_on_no_regs+0x38/0x58 [nvgpu]
__nvgpu_readl+0x74/0xc8 [nvgpu]
nvgpu_readl+0x28/0x60 [nvgpu]
xxxxx_ce_get_num_pce+0x28/0x70 [nvgpu]
xxxxx_fifo_init_eng_method_buffers+0x64/0x1c0 [nvgpu]
gk20a_tsg_open+0x110/0x1e0 [nvgpu]
nvgpu_ioctl_tsg_open+0x88/0x100 [nvgpu]
gk20a_ctrl_dev_ioctl+0x734/0x2388 [nvgpu]
do_vfs_ioctl+0xc4/0x918
SyS_ioctl+0x94/0xa8

This change fixes this issue by calling gk20a_busy()/gk20a_idle()
in nvgpu_ioctl_tsg_open()

Bug 2268533
JIRA NVGPU-1016

Change-Id: I578289e7eb60295d6b6169b754a5cc60f7546fd5
Signed-off-by: Preetham Chandru Ramchandra <pchandru@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1794324
Reviewed-by: Seshendra Gadagottu <sgadagottu@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-by: Vijayakumar Subbu <vsubbu@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/os/linux/ioctl_tsg.c b/drivers/gpu/nvgpu/os/linux/ioctl_tsg.c
index 4ef99ded..5d22d082 100644
--- a/drivers/gpu/nvgpu/os/linux/ioctl_tsg.c
+++ b/drivers/gpu/nvgpu/os/linux/ioctl_tsg.c
@@ -399,7 +399,14 @@ int nvgpu_ioctl_tsg_open(struct gk20a *g, struct file *filp)
                 goto free_ref;
         }
 
+        err = gk20a_busy(g);
+        if (err) {
+                nvgpu_err(g, "failed to power on, %d", err);
+                goto free_ref;
+        }
+
         tsg = gk20a_tsg_open(g, nvgpu_current_pid(g));
+        gk20a_idle(g);
         if (!tsg) {
                 nvgpu_kfree(g, priv);
                 err = -ENOMEM;