Deepak Nibade bf29bd9422 gpu: nvgpu: check engine ctx_status in wait_idle ...

We have following bug where GPU Host reports non-idle
when it should report engine idle

- if a context is preempted off the GPU, and there is
  no other context to load, NV_PGRAPH_ENGINE_STATUS
  will not be idle until new context is loaded

- this could cause gr_gk20a_wait_idle() to fail since
  here we rely only on NV_PGRAPH_ENGINE_STATUS to
  decide if engine is busy or not

To fix this, first check if context is valid or not
from NV_PFIFO_ENGINE_STATUS_CTX_STATUS

If context is invalid, return immediately
Otherwise, continue as before

Also, add accessors for invalid ctx_status

Bug 1826768

Change-Id: Id627be3f02e79f4beac59a8b5195d08eabf651f2
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/1237521
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

2016-10-19 10:49:04 -07:00

..

nvgpu

gpu: nvgpu: check engine ctx_status in wait_idle

2016-10-19 10:49:04 -07:00