From: Pekka Pessi <ppessi@xxxxxxxxxx>
Some clients depend on mailbox being empty before processing the
message. On RT kernel, the thread processing the message may be on
different CPU or running with higher priority than the interrupt
handler thread and they may act on the message before mailbox is
emptied.
Signed-off-by: Pekka Pessi <ppessi@xxxxxxxxxx>
Signed-off-by: Kartik Rajput <kkartik@xxxxxxxxxx>