If the FIFO of the card is small, many short messages are queued up to
the upper layers and the userspace. This change allows the applications
to set a minimum datalen they want from the drivers.
Create a common control function to avoid code duplication in each
Signed-off-by: Karsten Keil <firstname.lastname@example.org>
Signed-off-by: David S. Miller <email@example.com>