Re: [PATCH] atmel_serial: update the powersave handler to matchserial core

From: Haavard Skinnemoen
Date: Fri Sep 19 2008 - 12:16:19 EST


Michael Trimarchi <trimarchimichael@xxxxxxxx> wrote:
> > Michael Trimarchi wrote:
> > > > + /* we can not wake up if we're running on slow clock */
> > > > + atmel_port->may_wakeup = device_may_wakeup(&pdev->dev);
> > > > + if (atmel_serial_clk_will_stop())
> > > > + device_set_wakeup_enable(&pdev->dev, 0);
> > > > +
> > > This is not true, the wakeup in the slow clock is possible, configure the
> > > input pin of the serial device as a gpio, and wake up on gpio. Then you
> > > must reconfigure as a serial pin, and you can wake up on slow clock.
> >
> > Yes, but the current driver doesn't actually support that, does it?
> >
>
> Yes I know, but we can think about it and support when is possible
> to wake-up the serial device. Each serial device can change the status
> of the gpio-pin before suspendig and register and handler on it (I think one
> interrupt handler for all the serial that can do that), then reset it after resume.
> I think not all the serial device can do that in the atmel architectures but I suppose
> that can be very usefull for example in gprs application.

I agree it would be useful. It would require changing the port mux
configuration from the driver though, and there's no standardized
interface for doing that. Maybe this is a good motivation to come up
with one?

Btw, I assume the first character you receive will be lost when you do
this, right?

Haavard
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/