tree bef38581727c0696e7aac02df61ceb9a8a093685
parent fba594a848f6f35417a358565086d22c533c19c8
author Peter Hurley <peter@hurleysoftware.com> 1409693955 -0400
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1410218562 -0700

serial: Fix send_xchar() handlers

START_CHAR() & STOP_CHAR() can be disabled if set to '\0'
(__DISABLED_CHAR).  UART drivers which define a send_xchar()
handler must not transmit __DISABLED_CHAR.

Document requirement.

Affected drivers:
sunsab
sunhv

cc: David S. Miller <davem@davemloft.net>
cc: <sparclinux@vger.kernel.org>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>