[PATCH v14 2/4] CMDQ: Mediatek CMDQ driver

On 6 October 2016 at 18:31, Horng-Shyang Liao [off-list ref] wrote:

Back to our original statement, we need to flush all tasks to queue
in GCE HW; i.e. we need to use mbox_client_txdone after
mbox_send_message, or send tx_done once mailbox controller receive
message (task). However, we still need a way to notice done tasks to
clients. Currently, we don't have a good way to call callback in mailbox
framework. Therefore, CMDQ driver has its owner callback functions.

mbox_client_txdone() is called by the client driver when only it knows
the messages has been transmitted (i.e your submitted tasks are done).
Obviously the client driver should do any callbacks to its users
upstream.