error accessing cdrom device

I just installed Slackware on a laptop, but there are some CD & sound issues.

When I try to use the CD player, I get the message:
"Error accessing cdrom device. Please check to make sure CDROM support is compiled into the kernel, and that you have permission to access the device.

However,
bash-2.05a# mount
/dev/hda5 on / type ext2 (rw)
none on /dev/pts type devpts (rw,gid=5,mode=620)
none on /proc type proc (rw)
/dev/cdrom on /mnt/cdrom type iso9660 (ro,nosuid,nodev)
bash-2.05a# ls -al /dev/cdrom
lrwxrwxrwx 1 root root 8 Jul 13 19:15 /dev/cdrom -> /dev/hdb
bash-2.05a#

I also notice that when applications like Gaim try to BEEP or make a sound, the following message arrives on stderr:

/dev/dsp: No such device

But

bash-2.05a# ls -al /dev/dsp
crw-rw-rw- 1 root sys 14, 3 Jul 18 1994 /dev/dsp


any ideas guys?

Christo

just looking at the CDROM modules in /etc/rc.d/rc/modules, I see the following:

# ***NONE*** of these drivers are for use with IDE/ATAPI CD-ROM drives. That
# support is already built into every pre-compiled Slackware Linux kernel.

so I won't need to re-gen the kernel (shame )

any other ideas??

to your first problem:

for audio cdroms, you need access to the raw device (/dev/cdrom whis is a link to /dev/hdb here -> you have your cdrom on the primary slave port.)

/dev/cdrom is owned by root.root

are you logged in as root or is your user member of the "root" group? if not, you cannot acces it

can you mount a data cd-rom? (you still might be able to since mount is most times SUID root)

the second problem, /dev/dsp is independent of that. do you have your sound card (and the wave out device) configured?

/dev/dsp is the channel for outputting wav files. (try "cat /data/windows/media/chimes.wav >/dev/dsp")
could also be a permissions problem, but probably the sound card is not setup at all. is it?

Hi Manuel,
thanks for the feedback... here's where I am so far:

bash-2.05a$ ls -al /dev/cdrom
lrwxrwxrwx 1 root root 8 Jul 13 19:15 /dev/cdrom -> /dev/hdb

I'm not sure how to change the group membership of my user.

yes I can mount a data cd-rom okay

hmmm - probably not, but again, I'm not sure where to go with this.. I also noticed that when I try running mpg321, I get the message:

"No default libao driver available."

I don't have that path on my system... isn't that a windows thing?? I tried with a different file, and stlil get "/dev/dsp: No such device"

could also be a permissions problem, but probably the sound card is not setup at all. is it?

no and I think that could be the problem, but how do I set the thing up?

hmmm
christo

change group membership:
- edit /etc/group
- add your username to the line with "root:0:..."; separate multiple entries with commas.

also check "ls -l /dev/hdb" for i am not sure if links inherit their target´s permissions and/or ownership. for SuSE i think the group was "disk"...

setup sound card: this could fill a book of its own

which distro are you using? SuSE and Redhat have automated tools for this. i only know SuSE and the low-level way. SuSE: start "alsaconfig" (alsasetup?). you need to have the package "alsa" installed.
there is another sound driver package, "oss", which requires license fees so i doubt SuSE or Redhat still come with it.
some hardware manufacturers have install instructions also for linux on their homepage
and last, but not least - the kernel drivers. linux itself also has kernel modules for the most common sound cards.

which brand and type is it?

thanks for the /etc/group tip!

I managed to get the sound working by

a) changing /dev/dsp /audio and /mixer too permission level 666

b) modprobe maestro3

It turns out Slackware doesn't do any kind of audio config on installation.. infact lots of the post install setup is a bit mad..

The wierd thing is that I have to probe out that module after every reboot, and yet I remember only having to do it once when setting up my realtek NCI driver on RedHat.. Do I really have to throw a modprobe command into one of my startup scripts?

seems like an odd thing to do

thanks, dude

Christo

Slackware... uh, one for the hard ones

one solution is to put the "modprobe" in a startup script. not that odd. remember c:\config.sys?

another one is to edit /etc/conf.modules (/etc/modules.conf depends on distro) and setup automatic loading of modules when necessary...

alias snd-device-0 maestro3

(needs modification to work... see /var/log/messages for the correct "snd-device-0" after accessing /dev/dsp)

yeah, I switched to slack from redhat at the weekend.. I got frustrated with the funny looking tree under /usr/src and I also found that I prefer doing stuff from source and getting into bed more with the operating system... rpm's weren't pushing my button and as for that ximian red-carpet thing that everyone bangs on about, I have never seen such a pile of poo! I'll just see how it goes with Slack for a while

in the meantime, I better learn a few of the linux basics!! you're right about config.sys - i forgot about those days... so I'll see what I can do with my /etc/modules.conf.

RIght now I'm compiling a module...nothing like getting into the action I'll try installing it and booting in a while

christo

Well, just for completion, I successfully compiled support into my kernel for my sound card, so it's always there on boot, instead of having to probe out the module.

It seems like quite a powerful way of configuring the system - I mean, I have taken out lots of stuff that I don't need like support for file systems, harware devices and network protocols that I don't use and built in support for my USB devices and my sound card leaving me with a Linux kernel that works just the way I want.

I need to dream up some good ways of benchmarking these kernels to see what effects I am having on their performace.

Any ideas on benchmarking much appreciated!!

christo