On Wednesday 13 July 2011, Jiri Slaby wrote:

The same as in "TTY: serial, remove BTM from wait_until_sent" we don't
need to take BTM in wait_until_sent of ami_serial. Exactly the same
as serial, ami_serial accesses some "info" members (xmit_fifo_size,
timeout), but their assignment on other places in the code is not
protected by BTM anyway.

So the BTM protects nothing here. This removal helps us to get rid of
tty_locked() and __big_tty_mutex_owner in the following patch. This
was suggested by Arnd.

Signed-off-by: Jiri Slaby <redacted>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Alan Cox <redacted>
Cc: Andreas Bombe <redacted>

Acked-by: Arnd Bergmann <arnd@arndb.de>