On Wed, Apr 24, 2002 at 04:57:26PM -0700, Peter Jay Salzman wrote:
| begin dman <dman@dman.ddts.net>
| > On Wed, Apr 24, 2002 at 03:10:47PM -0700, David Smead wrote:
| > |
| > | I'm apparently missing a driver.
| > |
| > | knuth:~# lpq
| > ...
| > | Status: cannot open '/dev/lp0' - 'No such device'
| >
| > | -----------------
| > |
| > | knuth:~# ls -l /dev/lp0
| > | crw-rw---- 1 root lp 6, 0 Jun 13 2001 /dev/lp0
| >
| > This is meaningless. (well, all it means is you have an inode named
| > "lp0". You've got lots of inodes in /dev that you don't have hardware
| > for)
|
| meaningless?
"Linux doesn't see my SCSI disk, but look - /dev/sda1 is there."
Actually, the machine has no SCSI disks or controllers. The
presence of the device file has no bearing on the matter.
| the major and minor numbers are correct.
Ok, that is something worth verifying.
| the kernel certainly knows what major number 6 is. the parport
| driver (if present) knows what minor number 0 is.
|
| doesn't matter what you call the *file*. it's the major and minor
| numbers which matter.
|
| > If you use devfs this becomes meaningful (the file won't exist
| > unless the device and driver do).
|
| maybe. maybe not.
# lsmod | grep lp
lp 6208 0
# ls -l /dev/printers/0 /dev/lp0
crw-rw---- 1 root lp 6, 0 Dec 31 1969 /dev/printers/0
lr-xr-xr-x 1 root root 10 Apr 18 23:18 /dev/lp0 -> printers/0
# rmmod lp
# cd /lib/modules/2.4.18-custom.3/kernel/drivers/char/
# mv lp.o NOT-lp.o # (otherwise the kernel automatically loads it)
# ls -l /dev/printers/0 /dev/lp0
ls: /dev/printers/0: No such file or directory
ls: /dev/lp0: No such file or directory
The device files exist when I have the driver loaded, and don't exist
when I don't. That is why I said listing the file is meaningful only
when using devfs.
| depends on how devfsd is configured, doesn't it?
Yeah, if you configure devfsd wrong and/or check the wrong file :-).
-D
--
Consider what God has done:
Who can straighten what He has made crooked?
Ecclesiastes 7:13
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