Re: [PATCH] serial: fix enable_irq_wake/disable_irq_wake imbalancein serial_core.c

From: Andrew Morton
Date: Wed May 21 2008 - 17:54:20 EST


On Mon, 19 May 2008 20:11:41 -0700
Arjan van de Ven <arjan@xxxxxxxxxxxxxxx> wrote:

> From: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
> Subject: [PATCH] serial: fix enable_irq_wake/disable_irq_wake imbalance in serial_core.c
>
> enable_irq_wake() and disable_irq_wake() need to be balanced.
> However, serial_core.c calls these for different conditions during
> the suspend and resume functions...
>
> This is causing a regular WARN_ON() as found at
> http://www.kerneloops.org/search.php?search=set_irq_wake
>
> This patch makes the conditions for triggering the _wake
> enable/disable sequence identical.
>
> Signed-off-by: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
> ---
> drivers/serial/serial_core.c | 5 ++++-
> 1 files changed, 4 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
> index eab0327..4df9ee1 100644
> --- a/drivers/serial/serial_core.c
> +++ b/drivers/serial/serial_core.c
> @@ -2054,6 +2054,8 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
> int uart_resume_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);
>
> @@ -2063,7 +2065,8 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
> return 0;
> }
>
> - if (!port->suspended) {
> + tty_dev = device_find_child(port->dev, &match, serial_match_port);
> + if (!port->suspended && device_may_wakeup(tty_dev)) {
> disable_irq_wake(port->irq);
> mutex_unlock(&state->mutex);
> return 0;

erp, is that the easiest way of going from a uart_driver* to a device*?
Doing a lookup each time is a bit unusual.

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