Fix lockup in vdrm_host_sync()
The vdrm_execbuf()
missed to set the seqno field for requests sent to host. This causes vdrm_host_sync()
to lockup due to the unset seqno in a case where two or more threads are using vdrm_execbuf()
and vdrm_send_req()
concurrently, like in the following scenario:
thread1: vdrm_send_req() shmem->seqno=1 req->seqno=2
thread2: vdrm_execbuf() shmem->seqno=1 req->seqno=0
thread1: vdrm_host_sync() shmem->seqno=0 req->seqno=2