gpu: nvgpu: enable powergate always while releasing debug session

Currently, while releasing the debug session we enable powergate
only if a channel is bound to session

If a session has no channel bound to it, and has powergate
disabled, then we do not enable powergate when that session
is closed

Fix this by calling dbg_set_powergate(POWERGATE_ENABLE) always
while releasing the session

Refcounting and sanity checks in dbg_set_powergate() will take
care of situation if powergate was not disabled by the session
in first place

Bug 1679372

Change-Id: I4e027393c611d3e8ab4f20e195f31871086da736
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/796999
Tested-by: Sandarbh Jain <sanjain@nvidia.com>
Reviewed-by: Sandarbh Jain <sanjain@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 9 insertions, 6 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c b/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c
index c1cca445..4a175a3c 100644
--- a/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c
@@ -282,12 +282,6 @@ static int dbg_unbind_channel_gk20a(struct dbg_session_gk20a *dbg_s)
 
         --g->dbg_sessions;
 
-        /* Powergate enable is called here as possibility of dbg_session
-         * which called powergate disable ioctl, to be killed without calling
-         * powergate enable ioctl
-         */
-        dbg_set_powergate(dbg_s, NVGPU_DBG_GPU_POWERGATE_MODE_ENABLE);
-
         dbg_s->ch = NULL;
         fput(dbg_s->ch_f);
         dbg_s->ch_f = NULL;
@@ -303,6 +297,7 @@ static int dbg_unbind_channel_gk20a(struct dbg_session_gk20a *dbg_s)
 int gk20a_dbg_gpu_dev_release(struct inode *inode, struct file *filp)
 {
         struct dbg_session_gk20a *dbg_s = filp->private_data;
+        struct gk20a *g = dbg_s->g;
 
         gk20a_dbg(gpu_dbg_gpu_dbg | gpu_dbg_fn, "%s", dev_name(dbg_s->dev));
 
@@ -310,6 +305,14 @@ int gk20a_dbg_gpu_dev_release(struct inode *inode, struct file *filp)
         if (dbg_s->ch)
                 dbg_unbind_channel_gk20a(dbg_s);
 
+        /* Powergate enable is called here as possibility of dbg_session
+         * which called powergate disable ioctl, to be killed without calling
+         * powergate enable ioctl
+         */
+        mutex_lock(&g->dbg_sessions_lock);
+        dbg_set_powergate(dbg_s, NVGPU_DBG_GPU_POWERGATE_MODE_ENABLE);
+        mutex_unlock(&g->dbg_sessions_lock);
+
         kfree(dbg_s);
         return 0;
 }