From 9d778a69370cc1b643b13648df971c83ff5654ef Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 4 Feb 2008 22:27:51 -0800 Subject: [PATCH] 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 Acked-by: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/serial/serial_core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c index 0cf382b55d4b..2554d2fa6542 100644 --- a/drivers/serial/serial_core.c +++ b/drivers/serial/serial_core.c @@ -2029,8 +2029,6 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *port) } port->suspended = 0; - uart_change_pm(state, 0); - /* * Re-enable the console device after suspending. */ @@ -2049,6 +2047,7 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *port) if (state->info && state->info->tty && termios.c_cflag == 0) termios = *state->info->tty->termios; + uart_change_pm(state, 0); port->ops->set_termios(port, &termios, NULL); console_start(port->cons); } @@ -2057,6 +2056,7 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *port) const struct uart_ops *ops = port->ops; int ret; + uart_change_pm(state, 0); ops->set_mctrl(port, 0); ret = ops->startup(port); if (ret == 0) {