On Wed, 12 Sep 2007 20:50:10 +0200 (CEST)
Guennadi Liakhovetski <[EMAIL PROTECTED]> wrote:
> Enable wakeup from serial ports, make it run-time configurable over sysfs,
> e.g.,
>
> echo enabled > /sys/devices/platform/serial8250.0/tty/ttyS0/power/wakeup
>
> Requires
>
> # CONFIG_SYSFS_DEPRECATED is not set
>
> Signed-off-by: Guennadi Liakhovetski <[EMAIL PROTECTED]>
>
> ---
>
> Following suggestions from Alan and Russell moved the may_wake_up checks
> to serial_core.c. This time actually tested - it does even work. Could
> someone, please, verify, that put_device after device_find_child is
> correct?
Seems right to me, from reading device_find_child() and its associated
documentation.
> Also would be nice to test with a Natsemi UART, that can wake up
> the system, if such systems exist.
>
It would help if you could provide simple-to-follow steps which a tester
should follow to perform this testing.
>
> diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
> index 9c57486..8a3d6ea 100644
> --- a/drivers/serial/serial_core.c
> +++ b/drivers/serial/serial_core.c
> @@ -1934,9 +1934,24 @@ static void uart_change_pm(struct uart_state *state,
> int pm_state)
> }
> }
>
> +struct uart_match {
> + struct uart_port *port;
> + struct uart_driver *driver;
> +};
> +
> +static int serial_match_port(struct device *dev, void *data)
> +{
> + struct uart_match *match = data;
> + dev_t devt = MKDEV(match->driver->major, match->driver->minor) +
> match->port->line;
> +
> + return dev->devt == devt; /* Actually, only one tty per port */
> +}
> +
> int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
> {
> struct uart_state *state = drv->state + port->line;
> + struct device *tty_dev;
> + struct uart_match match = {port, drv};
>
> mutex_lock(&state->mutex);
>
> @@ -1947,6 +1962,15 @@ int uart_suspend_port(struct uart_driver *drv, struct
> uart_port *port)
> }
> #endif
>
> + tty_dev = device_find_child(port->dev, &match, serial_match_port);
> + if (device_may_wakeup(tty_dev)) {
> + enable_irq_wake(port->irq);
> + put_device(tty_dev);
> + mutex_unlock(&state->mutex);
> + return 0;
> + }
> + port->suspended = 1;
> +
> if (state->info && state->info->flags & UIF_INITIALIZED) {
> const struct uart_ops *ops = port->ops;
>
> @@ -1995,6 +2019,13 @@ int uart_resume_port(struct uart_driver *drv, struct
> uart_port *port)
> }
> #endif
>
> + if (!port->suspended) {
> + disable_irq_wake(port->irq);
> + mutex_unlock(&state->mutex);
> + return 0;
> + }
> + port->suspended = 0;
> +
> uart_change_pm(state, 0);
>
> /*
> @@ -2266,6 +2297,7 @@ int uart_add_one_port(struct uart_driver *drv, struct
> uart_port *port)
> {
> struct uart_state *state;
> int ret = 0;
> + struct device *tty_dev;
>
> BUG_ON(in_interrupt());
>
> @@ -2301,7 +2333,13 @@ int uart_add_one_port(struct uart_driver *drv, struct
> uart_port *port)
> * Register the port whether it's detected or not. This allows
> * setserial to be used to alter this ports parameters.
> */
> - tty_register_device(drv->tty_driver, port->line, port->dev);
> + tty_dev = tty_register_device(drv->tty_driver, port->line, port->dev);
> + if (likely(!IS_ERR(tty_dev))) {
> + device_can_wakeup(tty_dev) = 1;
> + device_set_wakeup_enable(tty_dev, 0);
> + } else
> + printk(KERN_ERR "Cannot register tty device on line %d\n",
> + port->line);
>
> /*
> * If this driver supports console, and it hasn't been
> diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
> index 773d8d8..60dedc0 100644
> --- a/include/linux/serial_core.h
> +++ b/include/linux/serial_core.h
> @@ -291,7 +291,8 @@ struct uart_port {
> unsigned long mapbase; /* for ioremap */
> struct device *dev; /* parent device */
> unsigned char hub6; /* this should be in
> the 8250 driver */
> - unsigned char unused[3];
> + unsigned char suspended;
> + unsigned char unused[2];
> void *private_data; /* generic platform
> data pointer */
> };
>
-
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