Hello,

I'm running Debian sid using Debian-patched kernels. I'm trying to get my cd drives recognised using a newer kernel. Using my last working kernel, 2.6.24-1-686, my two IDE-connected cd/dvd drives are detected as /dev/sr0 and /dev/sr1, symlinked to cdrom0 and cdrom1, and work fine. When I boot using new kernel, 2.6.25-2-686-bigmem, no entries for these devices appear in /dev.

With the working kernel, the relevant part of dmesg is:

scsi7 : SCSI emulation for USB Mass Storage devices
usb-storage: device found at 2
usb-storage: waiting for device to settle before scanning
ata5.00: ATAPI: HL-DT-STDVD-RAM GSA-H55L, 1.05, max UDMA/66
ata5.01: ATAPI: HL-DT-ST DVD-ROM GDR-H30N, 1.00, max UDMA/33
usb 7-2: new low speed USB device using uhci_hcd and address 2
ata5.00: configured for UDMA/66
usb 7-2: configuration #1 chosen from 1 choice
ata5.01: configured for UDMA/33
BAR5:00:02 01:7F 02:22 03:CA 04:00 05:00 06:00 07:00 08:00 09:00 0A:00
0B:00 0C:07 0D:00 0E:00 0F:00

With the bigmem kernel, what looks like the corresponding part of
dmesg:

[ 0.812202] PCI: Setting latency timer of device 0000:03:00.0 to 64
[ 0.812281] scsi5 : ahci
[ 0.812455] scsi6 : ahci
[ 0.812583] scsi7 : ahci
[ 0.812645] ata5: SATA max UDMA/133 abar m1024@0xfeaffc00 port
0xfeaffd00 irq 16
[ 0.812705] ata6: SATA max UDMA/133 abar m1024@0xfeaffc00 port
0xfeaffd80 irq 16
[ 0.812765] ata7: DUMMY
[ 0.874732] usb 7-1: configuration #1 chosen from 1 choice
[ 0.875046] scsi8 : SCSI emulation for USB Mass Storage devices
[ 0.875218] usb 7-1: New USB device found, idVendor=04b4,
idProduct=6830

There are no error messages referring to the DVD drives elsewhere in
dmesg.

There's a slight difference in the output of lsmod | grep ide between
the two kernels. For the working kernel:

ide_cd 36224 0
cdrom 32512 2 ide_cd,sr_mod
ide_core 108292 2 ide_cd,generic

For the bigmem kernel that doesn't detect the drives:

ide_cd_mod 33632 0
cdrom 32640 2 sr_mod,ide_cd_mod
ide_pci_generic 4996 0 [permanent]
ide_core 101624 2 ide_cd_mod,ide_pci_generic

I have ide-core, ide-cd, cdrom and sr_mod listed in /etc/modules to
try to ensure relevant stuff gets loaded at boot.

I'd appreciate any advice about next steps for tracking down the
problem.

Thanks.

Hi!
Sorry, your cd-drives are connected to the PC through USB, PATA or SATA?
And what happens if you do a "modprobe ide_cd_mod"?
And the kernel, did you configure & compile it on your own or did you use the one that was delivered by your distribution?
Thanks

For reasons, I don't quite know, the kernel from the distribution I use brings up the sata dvd as /dev/hdc. But when I build my own kernel, it shows up as /dev/sr0. So you should look at /dev/hda through /dev/hdd. If not there you will likely have to review hardware and settings in ide, scsi, sata and pata portion when running make xconfig or menuconfig.

Thanks for the suggestions. The kernels were pre-compiled packages from the Debian unstable repository; I did not alter them. When detected, the devices were located at /dev/scd0 and /dev/scd1, not hdx.

The problem was solved by adding 'pata_marvell' to /etc/initramfs-tools/modules and then rebuilding the initial boot image by typing 'sudo update-initramfs -u'.

My guess is that pata_marvell wasn't being loaded early enough.

Last couple of days I was reviewing my kernel config files and realized I hadn't loaded the pata driver for ati on a previous kernel. With the pata built in, my dvd (sata but in ide-mode in bios) shows up as /dev/hdc. But, with pata driver not loaded, the kernel loads scsi and the dvd shows up as /dev/sr0.

Sounds like we both understand why our systems acted as they did.