We store a reference to common address space of channels
in struct tsg_gk20a without increasing the refcount
This could result in freeing the address space even when
some channel in TSG needs it or when we need to free
common gr_ctx
Fix this by getting ref using gk20a_vm_get() when we store
the VM reference. We drop this reference with
gk20a_vm_put() when closing the TSG
Bug 1470692
Change-Id: Ifc1f29d32cd721810bfbb5a4db96095770318c17
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/495668
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>