serial: avoid waking up closed serial ports on resume
authorRussell King <rmk+lkml@arm.linux.org.uk>
Tue, 5 Feb 2008 06:27:51 +0000 (22:27 -0800)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Tue, 5 Feb 2008 17:44:09 +0000 (09:44 -0800)
commit9d778a69370cc1b643b13648df971c83ff5654ef
treee32a231699733217a8ab2f42893c6e5b5cf97a97
parent74a197417240120d638d67d74f48655fb7f46f16
serial: avoid waking up closed serial ports on resume

When we boot, serial ports remain in low power mode until they're used either
by userspace or for the kernel console.

However, if you suspend the system, and then resume, all serial ports will be
taken out of low power mode.  This is bad news for embedded devices where this
can mean higher power consumption.

Only bring a serial port out of low power mode if the port is being used as
the kernel console, or is in use by userspace.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/serial/serial_core.c