On Mon, 13 Aug 2007, Scott Wood wrote:
> Guennadi Liakhovetski wrote:
> >
> > # ls -l /sys/devices/platform/serial8250.0/tty*
> > lrwxrwxrwx 1 root root 0 Aug 13 22:05
> > /sys/devices/platform/serial8250.0/tty:ttyS0 -> ../../../class/tty/ttyS0
> > lrwxrwxrwx 1 root root 0 Aug 13 22:05
> > /sys/devices/platform/serial8250.0/tty:ttyS1 -> ../../../class/tty/ttyS1
> >
> > And placing some wakeup file under the class/tty/ directory doesn't seem
> > very consistent with the current policy - until now they only live under
> > devices/... (Greg added to cc:).
>
> Hmm... I'd assumed each port would have its own device directory. Would
> anything break horribly if it were changed so that each tty:ttySx is a
> directory, which contains both a wakeup file and the symlink?
Yeah, I'd love to know the answer too:-) As you see, atm it is one
platform device as defined in arch/powerpc/kernel/legacy_serial.c:
static struct platform_device serial_device = {
.name = "serial8250",
.id = PLAT8250_DEV_PLATFORM,
.dev = {
.platform_data = legacy_serial_ports,
},
};
with a list of ports in platform data:
static struct plat_serial8250_port
legacy_serial_ports[MAX_LEGACY_SERIAL_PORTS+1];
Hence one device directory. Same on a PC
$ ls -l /sys/devices/platform/serial8250/tty*
lrwxrwxrwx 1 root root 0 Aug 13 23:10
/sys/devices/platform/serial8250/tty:ttyS0 -> ../../../class/tty/ttyS0
lrwxrwxrwx 1 root root 0 Aug 13 23:10
/sys/devices/platform/serial8250/tty:ttyS1 -> ../../../class/tty/ttyS1
lrwxrwxrwx 1 root root 0 Aug 13 23:10
/sys/devices/platform/serial8250/tty:ttyS2 -> ../../../class/tty/ttyS2
lrwxrwxrwx 1 root root 0 Aug 13 23:10
/sys/devices/platform/serial8250/tty:ttyS3 -> ../../../class/tty/ttyS3
> You should get the interrupt, but not until after the PM code enables IRQs.
> Are you saying that the interrupt handler runs before then?
Great, it is working correctly then! Don't think the ISR runs return from
PM, no.
Thanks
Guennadi
---
Guennadi Liakhovetski
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