gpu: nvgpu: fix event id polling

In gk20a_event_id_poll(), we always set the mask value
and return it. This causes poll() from UMD to be always
successful irrespective of event is really generated or not

Fix this by adding a flag event_posted for each event
Set this flag while posting the event
In gk20a_event_id_poll(), set the mask value only if
this flag is set. If flag is set, set mask and clear the flag

Bug 200089620

Change-Id: If14236547c611fe4bfa1410ff5b69c9fa02d43bb
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/1160253
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/channel_gk20a.h b/drivers/gpu/nvgpu/gk20a/channel_gk20a.h
index 29a13d24..4e0db3cf 100644
--- a/drivers/gpu/nvgpu/gk20a/channel_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/channel_gk20a.h
@@ -84,6 +84,8 @@ struct gk20a_event_id_data {
         bool is_tsg;
         u32 event_id;
 
+        bool event_posted;
+
         wait_queue_head_t event_id_wq;
         struct mutex lock;
         struct list_head event_id_node;