gpu: nvgpu: Add refcounting to driver fds

The main driver structure is not refcounted properly,
so when the driver unload, file desciptors associated to the
driver are kept open with dangling references to the main object.

This change adds referencing to the gk20a structure.

bug 200277762
JIRA: EVLR-1023

Change-Id: Id892e9e1677a344789e99bf649088c076f0bf8de
Signed-off-by: David Nieto <dmartineznie@nvidia.com>
Reviewed-on: http://git-master/r/1317420
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c b/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c
index 821951ad..7eb742ed 100644
--- a/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c
@@ -101,13 +101,17 @@ static int gk20a_dbg_gpu_do_dev_open(struct inode *inode,
         else
                 g = container_of(inode->i_cdev,
                                  struct gk20a, prof.cdev);
+        g = gk20a_get(g);
+        if (!g)
+                return -ENODEV;
+
         dev = g->dev;
 
         gk20a_dbg(gpu_dbg_fn | gpu_dbg_gpu_dbg, "dbg session: %s", dev_name(dev));
 
         err  = alloc_session(&dbg_session);
         if (err)
-                return err;
+                goto free_ref;
 
         filp->private_data = dbg_session;
         dbg_session->dev   = dev;
@@ -133,6 +137,8 @@ err_destroy_lock:
         nvgpu_mutex_destroy(&dbg_session->ch_list_lock);
 err_free_session:
         kfree(dbg_session);
+free_ref:
+        gk20a_put(g);
         return err;
 }
 
@@ -494,6 +500,8 @@ int gk20a_dbg_gpu_dev_release(struct inode *inode, struct file *filp)
         nvgpu_mutex_destroy(&dbg_s->ioctl_lock);
 
         kfree(dbg_s);
+        gk20a_put(g);
+
         return 0;
 }