gpu: nvgpu: check for valid channel ctx before preempt

Always check for valid channel gr_ctx before issuing channel
preempt. Commands like "echo > /dev/nvhost-gpu" create channel
to just power-up gpu without any valid channel context. So
don't try to preempt those channels.

Bug 1937331

Change-Id: I48a4bfd35728b83b27eb968e51a56b900d1fa799
Signed-off-by: seshendra Gadagottu <sgadagottu@nvidia.com>
Reviewed-on: http://git-master/r/1505783
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
index 1caecf3d..ef9ad731 100644
--- a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
@@ -294,7 +294,7 @@ void gk20a_channel_abort(struct channel_gk20a *ch, bool channel_preempt)
 
         ch->g->ops.fifo.disable_channel(ch);
 
-        if (channel_preempt)
+        if (channel_preempt && ch->ch_ctx.gr_ctx)
                 ch->g->ops.fifo.preempt_channel(ch->g, ch->hw_chid);
 
         gk20a_channel_abort_clean_up(ch);