gpu: nvpgu: free hw_sema before as binding

Free the hw_sema before releasing a channel's address space
binding when freeing a channel. Since the semaphore pool
can be freed after releasing the address space, we need
to do this earlier on.

Bug 1795076

Change-Id: Ic8ae7510af7be862feb6694130c6ce8fc0b8e411
Signed-off-by: Sachit Kadle <skadle@nvidia.com>
Reviewed-on: http://git-master/r/1208071
(cherry picked from commit 82a52fb6789b1c9361c1567f082ca36135287294)
Reviewed-on: http://git-master/r/1209165
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 8 insertions, 4 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
index 79d449e6..795c7910 100644
--- a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
@@ -951,6 +951,14 @@ static void gk20a_free_channel(struct channel_gk20a *ch)
         }
         mutex_unlock(&ch->sync_lock);
 
+        /*
+         * free the channel used semaphore index.
+         * we need to do this before releasing the address space,
+         * as the semaphore pool might get freed after that point.
+         */
+        if (ch->hw_sema)
+                gk20a_semaphore_free_hw_sema(ch);
+
         /* release channel binding to the as_share */
         if (ch_vm->as_share)
                 gk20a_as_release_share(ch_vm->as_share);
@@ -974,10 +982,6 @@ unbind:
         g->ops.fifo.unbind_channel(ch);
         g->ops.fifo.free_inst(g, ch);
 
-        /* free the channel used semaphore index */
-        if (ch->hw_sema)
-                gk20a_semaphore_free_hw_sema(ch);
-
         ch->vpr = false;
         ch->vm = NULL;