8250_pnp is confused... (udev?)

8250_pnp is confused... (udev?)

[Jeff Wiegley]

I've used serial ports a lot in the past but not for the
past year so. Did something fundamental change?

I have serial_core, 8250 and 8250_pnp modules installed
and things are quite weird... I get all of the /dev/ttyS's
that I DON'T have and none of the ones that I do!

$modprobe -a 8250_pnp
$tail /var/log/message
May 21 22:59:35 home Serial: 8250/16550 driver $Revision: 1.90 $ 4
ports, IRQ sharing disabled
May 21 22:59:35 home pnp: Device 00:07 activated.
May 21 22:59:35 home 00:07: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A

So, yes it looks like it sees the one serial port that I also
think I have. but...

$ls -al /dev/ttyS*
crw-rw---- 1 root uucp 4, 65 May 21 22:59 /dev/ttyS1
crw-rw---- 1 root uucp 4, 66 May 21 22:59 /dev/ttyS2
crw-rw---- 1 root uucp 4, 67 May 21 22:59 /dev/ttyS3

It seems that somehow either 8250_pnp (or maybe udev) gets the
logic inverted. It doesn't create a device for the one device
that 8250_pnp found and yet it does create devices for everything
NOT found??

If I rmmod 8250_pnp 8250 serial_core then all the serial devices
go away. So it's 8250/udev creating these oddities and not me.

I am using gentoo with kernel v2.6.21.1 on an intel 64 bit dual-core
with Nvidia 580i chipset. I haven't tweaked any udev rules. udev is
version 104-r12.

Any help is appreciated. Thanks!

- Jeff

Re: 8250_pnp is confused... (udev?)

[Konstantin Kletschke]

Am 2007-05-21 23:05 -0700 schrieb Jeff Wiegley:
> I've used serial ports a lot in the past but not for the
> past year so. Did something fundamental change?

I use a serial PCI adaptor:

00:0b.0 Serial controller: NetMos Technology PCI 9835 Multi-I/O
Controller (rev 01)

Well, I have also not used ttyS2 for a while and recently I realized, it
does not like, when I past with a mouse a line into any terminal with a
line break (Input Output Error). ttyS1 (same card) works fine.

> and things are quite weird... I get all of the /dev/ttyS's
> that I DON'T have and none of the ones that I do!

When I have 8250* build as modules I get:

ttyS0: OnBoard
ttyS1: PCI card, first Port
ttyS3: bogus, could have been meant to become ttyS2, second Port.

So there is weird stuff going on since recent Kernel versions. May be
since 2.6.19 until 2.6.21 (As said, I did not use the ttyS2 for a
while).

Konsti


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