Yet another problem w/ CD-RW drive (RH8)

kbrown · 03-22-2003, 07:34 AM

Hi,

This is my first post here. I have a relatively fresh install of RH8 and I'm having hard time with my CD-RW drive.

To cut long story short: If I have hdc=ide-scsi in /etc/grub.conf, GnomeToaster sees the drive as a writer. But If I insert a regular data CD in the drive, the whole system freezes after a while. I believe automount is trying to mount it but it fails for some reason.

If I remove the hdc=ide-scsi from grub.conf, I can use the drive to read my CDs but GnomeToaster can't find any writers on my system.

Is this the deal? I can't have my drive acting as both a reader and writer? Is the scsi emulation buggy or something?

here's my /etc/fstab:

Code:

LABEL=/                 /                       ext3    defaults        1 1
none                    /dev/pts                devpts  gid=5,mode=620  0 0
none                    /proc                   proc    defaults        0 0
none                    /dev/shm                tmpfs   defaults        0 0
/dev/hda6               swap                    swap    defaults        0 0
/dev/fd0                /mnt/floppy             auto    noauto,owner,kudzu 0 0
/dev/hda3               /mnt/w2k                ntfs    ro,umask=0222   0 0
/dev/hdb5               /mnt/av                 ntfs    ro,umask=0222   0 0
/dev/cdrom              /mnt/cdrom              iso9660 noauto,owner,kudzu,ro 0 0

I'm running 2.4.18-27.8.0smp kernel if that counts...

Thanks.

kbrown · 03-22-2003, 07:41 AM

Little addition:

When hdc=ide-scsi, /dev/cdrom points to /dev/scd0
and when not, it points to /dev/hdc...

kbrown · 03-23-2003, 01:01 PM

Right, did some testing with the ide-scsi emulation on. Booted to console and observed /var/log/messages while trying to mount the cdrom. Here's what I got:

Code:

Attached scsi CD-ROM sr0 at scsi0, channel 0, id 0, lun 0
sr0 : scsi3-mmc drive: 32x/32x writer cd/rw xa/form2 cdda tray
Uniform CD-ROM driver Revision: 3.12
scsi: aborting command due to timeout: pid 15, scsi0, channel 0, id 0, lun 0 Read (10) 00 00 00 00 10 00 00 01 00
hdc: timeout waiting for DMA
ide_dmaproc: chipset supported ide_dma_timeout func only: 14

These were the last messages and after those the system freezed. Any ideas?

I remember reading from the dirve's manual something about disabling the DMA but I have no idea how to do that in linux...

kbrown · 03-23-2003, 03:40 PM

Ok, problem solved. Disabling DMA for the CD-RW drive did it. Now I can mount and burn CDs

Now how can I make it so that it disables the DMA automatically at boot time? hdparm -k1 /dev/hdc or hdparm -K1 /dev/hdc didn't work...