I've seen references to this scattered about on the web, but no solutions.
I installed FC6 on a Dell Inspiron 4000 laptop to use as a serial console for
debugging kernel problems. Whenever I start minicom on the laptop, however, I'm
greeted with a permission denied error to /dev/ttyS0. Sure enough, the perms on
ttyS0 are 0660 and I'm not a member of the uucp group:
crw-rw---- 1 root uucp 4, 64 Dec 1 06:04 /dev/ttyS0
crw-rw---- 1 root uucp 4, 65 Dec 1 06:03 /dev/ttyS1
crw-rw---- 1 root uucp 4, 66 Dec 1 06:03 /dev/ttyS2
crw-rw---- 1 root uucp 4, 67 Dec 1 06:03 /dev/ttyS3
No problem, I thought -- I'll just gin up a udev rule and set the perms to 0666.
Sorry; doesn't work. As a matter of fact, it gets worse: perms on ttyS0 go to
0600 root:root as a result of my new local rule.
Okay, not an ideal solution, but let's modify 50-udev.rules and set the default
rule for tty[A-Z]* to MODE="0666". Nope. Now they're *all* 0600 root:root.
Here's the rule:
KERNEL=="ttyS0", NAME="%k", GROUP="uucp", MODE="0666"
I had no problems with this under Debian Etch and Knoppix Live running on the
same laptop. Debian was running a 2.6.17 kernel, and for the life of me I can't
remember the Knoppix kernel version (the web site says 2.6.x -- big help), and I
don't have the CD here at home.
The current workaround is to add non-root users to the uucp group. (Or maybe
this is the solution?) Any ideas why I can't get a udev rule to change the
perms to 0666 on /dev/ttyS0?
Thanks,
Jay
