Re: Christmas list for the kernel

Marc Koschewski
2005-11-23T16:02:19Z

* Jon Smirl <jonsmirl@gmail.com> [2005-11-23 10:19:19 -0500]:

> On 11/23/05, Russell King <rmk+lkml@arm.linux.org.uk> wrote:
> > On Wed, Nov 23, 2005 at 09:43:58AM -0500, Jon Smirl wrote:
> > > My system has:
> > > 2 serial
> > >
> > > In /sys/bus/platform/devices I see this:
> > > serial8250
> > > shouldn't there be entries for all of the legacy devices?
> > >
> > > In /dev
> > > ttyS0
> > > ttyS1
> > > ttyS2
> > > ttyS3
> >
> > You're basically confused about serial ports. The kernel serial devices
> > whether or not hardware is found, to allow programs such as setserial to
> > function.
> >
> > If you disagree with that, there'll be an equal number of people who
> > have serial cards that need setserial who will in turn disagree with
> > you.
>
> This is confusing...
>
> Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing disabled
> serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
> serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
> serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
> serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
>
> /sys/bus/platform/devices/serial8250
> [jonsmirl@jonsmirl serial8250]$ ls
> bus driver power tty:ttyS0 tty:ttyS1 tty:ttyS2 tty:ttyS3 uevent
> [jonsmirl@jonsmirl serial8250]$
>

Mine looks like this.

* Why is the seconf line for ttyS1 missing (as you have one above)?
* What does these 'too much work' messages mean? Must have been come
in lately...

marc@stiffy:~$ dmesg | grep -i serial
Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing enabled
serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
serial8250: too much work for irq3
serial8250: too much work for irq3
serial8250: too much work for irq3
serial8250: too much work for irq3
serial8250: too much work for irq3
marc@stiffy:~$ ls /sys/bus/platform/devices/serial8250/
insgesamt 0
832 drwxr-xr-x 3 root root 0 2005-11-23 16:57 ./
12 drwxr-xr-x 7 root root 0 2005-11-23 09:21 ../
2452535 lrwxrwxrwx 1 root root 0 2005-11-23 16:58 bus -> ../../../bus/platform/
2452533 lrwxrwxrwx 1 root root 0 2005-11-23 16:58 driver -> ../../../bus/platform/drivers/serial8250/
833 drwxr-xr-x 2 root root 0 2005-11-23 09:21 power/
2452534 lrwxrwxrwx 1 root root 0 2005-11-23 16:58 tty:ttyS1 -> ../../../class/tty/ttyS1/
2452536 --w------- 1 root root 4096 2005-11-23 09:20 uevent
marc@stiffy:~$

Marc