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Old 02-16-2005, 03:19 AM   #1
vonkempelen
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Registered: Feb 2005
Location: Australia
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udev or devfs in use?


I have installed Slackware 10 and compiled my own kernel 2.6.9.

I know I enabled hotplug in the kernel, but I really have no idea how to tell if my install is using udev or devfs (or both if that is possible).

As far as I can tell I do have udev installed - swaret --search udev reports:
swaret 1.6.2-1
Listing available Packages matching Keyword: udev...
udev-050-i486-1 (169 kB) [Status: NOT INSTALLED (Installed: udev-042-i486-1)]

But is it configured properly and used?

I also have a lot of files in the /dev directory which leads me to believe devfs is also used.

Is there some definitive way to tell which one is actually in use?

I would like to use udev if possible but I am not sure how to remove devfs in that case.

Thank you.
 
Old 02-16-2005, 03:48 AM   #2
satinet
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Hello,

The 2.6 kernel uses udev unless I am much mistaken.

do 'ps -ef|grep -i udev' to see what it's up to.

I had a load of udev problems once and had to get right into the whole things, but I've forgotten all about it now. Can't even remember where the config files are.

Anyway, are you having some sort of problem? I'll try to remind myself, if so.
 
Old 02-16-2005, 04:26 AM   #3
vonkempelen
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Hi,

Thank you for that suggestion.

The result was "root 283 1 0 Feb13 ? 00:00:00 udevd" so I guess I can at least be sure that udev is present.

My problem started when I wanted to use my USB modem. I had it running on RH, kernel 2.4.x with no intervention on my part. RH simply detected the modem and created a node for it, I think it was /dev/input/ttyACM0 or something simmilar.

I tried creating the same node manually now, but it did not help. Basically the problem is that the modem module does not seem to detect the modem (the USB does see it - cat /proc/bus/usb/devices and also the cdc_acm module gets loaded but that's it)

And with this new udev system I am not even sure where the problem is. From reading the doumentation I was under the impression that it was supposed to be the module (or udev?) that was meant to create the node in first place.

Although the problem may be elsewhere and I am going in the completely wrong direction.
 
Old 02-16-2005, 10:56 AM   #4
urka58
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I'd suggest you first chek if the module is actually up by
lsmod
Udev is far from perfection, so it possible the device node is not created automatically when the module is loaded.
If you know what major number should be assigned to your device node, it is not a big problem since you can add a simple script to create this node at boot. I would check the driver docs first and then if nothing is availble have a look @ http://www.lanana.org/docs/device-list/.
Hope this helps
Ciao
 
Old 02-16-2005, 01:07 PM   #5
satinet
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hello,

I has similar problems with UDEV after a kernel recomplile. Basically, it couldn't see my cdrom drive. Anyway, I can't remember how i solved it, but i think i upgraded UDEV to the lastest version and recompiled.

The version of Udev in slack 10 is pretty early and as urka58 says, it's far from perfect. Anyway, if you cd to /dev then plug your USB modem into the slot it should create a new device. the operative word being 'should'. If you do 'ls -lsrt' after a few mins the latest device should be there. If it doesn't then i guess there is a problem.

I'm not an expert on UDEV. But check the config files - they tell you what kind of device should be created.

Get udev from www.slackware.com in the current part. You can search.
 
Old 02-17-2005, 03:45 AM   #6
vonkempelen
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OK, so far I have done this:

1) upgraded udev to the latest package
swaret --search udev
swaret 1.6.2-1

Listing available Packages matching Keyword: udev...
udev-050-i486-1 (169 kB) [Status: INSTALLED]

2) made sure it is running
ps -A | grep udev
247 ? 00:00:00 udevd

3) manually created the ACM node
mknod /dev/ttyACM0 c 166 0
chmod a+rw /dev/ttyACM0

4) made sure the modem module gets loaded when modem plugged in
lsmod
Module Size Used by
cdc_acm 9824 0
usblp 11072 0
ohci_hcd 15492 0
ehci_hcd 25156 0
usbcore 102500 6 cdc_acm,usblp,ohci_hcd,ehci_hcd

So far everything seems OK, yet the module does not see the modem

cat /proc/bus/usb/devices
T: Bus=03 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=12 MxCh= 0
D: Ver= 1.00 Cls=02(comm.) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1
P: Vendor=06ea ProdID=0002 Rev= 1.00
S: Manufacturer=Sirius Technologies
S: Product=Roadster II 56 USB
C:* #Ifs= 2 Cfg#= 1 Atr=a0 MxPwr=400mA
I: If#= 1 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=(none)
E: Ad=81(I) Atr=02(Bulk) MxPS= 16 Ivl=0ms
E: Ad=01(O) Atr=02(Bulk) MxPS= 16 Ivl=0ms
I: If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=02 Prot=01 Driver=(none)
E: Ad=82(I) Atr=03(Int.) MxPS= 8 Ivl=128ms

And Minicom dies with this error:
minicom: cannot open /dev/ttyACM0: No such file or directory

I am stumped. :-(
 
  


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