# no /dev/ttyS0, /dev/ttyS1

## GungHo

Hi all,

when wanting to send a fax I had to reanimate my old modem, attached to /dev/ttyS1. The kernel modules for the V24 ports are loaded

```
# lsmod | grep 8250    

8250_pnp                9152  0 

8250                   20788  1 8250_pnp

serial_core            18240  1 8250
```

and there are two tty ports in dmesg

```
# dmesg | grep tty             

00:07: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A

00:08: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
```

But there are no device files in the /dev directory, but the entries in /dev/tts are there:

```
[/dev/tts]# ls -l --color=never 

total 0

lrwxrwxrwx 1 root root 8 2007-08-29 19:33 0 -> ../ttyS0

lrwxrwxrwx 1 root root 8 2007-08-29 19:33 1 -> ../ttyS1

lrwxrwxrwx 1 root root 8 2007-08-29 19:33 2 -> ../ttyS2

lrwxrwxrwx 1 root root 8 2007-08-29 19:33 3 -> ../ttyS3
```

(by the way, what a fucking colorscheme in ls, yellow letters on white   :Embarassed:   :Evil or Very Mad:   :Rolling Eyes:  )

After making the entries in /dev and additionally a symlink called /dev/modem all works well:

```
# cd /dev

# mknod ttyS0 c 4 64

# mknod ttyS1 c 4 65

# ln -s ttyS1 modem

# setserial -a -v /dev/ttyS0

/dev/ttyS0, Line 0, UART: 16550A, Port: 0x03f8, IRQ: 4

Baud_base: 115200, close_delay: 50, divisor: 0

closing_wait: 3000 Flags: spd_normal skip_test

# [root@BlackHole:/dev]# setserial -a -v /dev/ttyS1

/dev/ttyS1, Line 1, UART: 16550A, Port: 0x02f8, IRQ: 3

Baud_base: 115200, close_delay: 50, divisor: 0

closing_wait: 3000 Flags: spd_normal skip_test
```

But why are the /dev/ttyS[01] entries not automatically created ? May be I'm wrong, but should they not be created by udev, or provided by one of the V24 related kernelmodules ?

By the way:

```
# uname -a

Linux BlackHole 2.6.22-gentoo-r5 #1 PREEMPT Fri Aug 24 17:24:30 CEST 2007 i686 AMD Athlon(tm) XP 2400+ AuthenticAMD GNU/Linux

# qlist -ICv udev

sys-fs/udev-114
```

Who can tell me whats going wrong in this case ?

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## keyson

Hi,

Noticed this also. But if you do a 'udevtrigger' it would create this devices.

Don't know why it was behaving this way and hade not got the time to dig into

this. So i compiled the serial driver into the kernel then it created the dev nodes.

Maybe the udev is run before it is probing this modules so it need's a reload 'udevtrigger'

to create the nodes. Try it out if you like.

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## GungHo

Hi keyson,

thanks, I'll give it a try

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## kristov

See

https://forums.gentoo.org/viewtopic-t-557940-highlight-.html

for a solution to this problem (which worked for me, at least).

Regards,

  Christoph

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