[blfs-support] CDROM not being detected

Victor Wren vwren at ponyhome.com
Fri Mar 25 06:16:08 PDT 2016

This should maybe be on LFS-SUPPORT, but I ran into problems when I 
started populating X11 with apps that needed access to the cdrom, so 
here I am.  I'm pulling my hair out over this.  I'm upgrading from an 
LFS 6.1 system that I've used for years, going with the 7.9 book.
Instead of the 4.4.2 kernel, I used the 4.4.4 kernel.  I've compared the 
kernel config between my last install and the
current install, and I can't see any differences.  The system, however, 
is not seeing the SATA CDROM at all.
/proc/sys/dev/cdrom/info has all empty fields.  Obviously there's no 
/dev/sr0 device, so there's nothing for udev to work with.  I can find 
no messages in dmesg related to the cdrom.

When I boot it off of my RIP-Linux USB drive, it sees the cdrom drive 
just fine, and I can boot from CD, so the drive is functional and 
recognized by other Linux variants.

Here's the SCSI and SATA parts of my kernel config, (with the "not 
configured" lines skipped):
# SCSI device support

# SCSI support type (disk, tape, CD-ROM)
# SCSI Transports
# Controllers with non-SFF native interface
# CD-ROM/DVD Filesystems

lspci shows this for my on-board SATA controller:

00:1f.2 SATA controller: Intel Corporation 82801IR/IO/IH (ICH9R/DO/DH) 6 
port SATA Controller [AHCI mode] (rev 02) (prog-if 01 [AHCI 1.0])
         Subsystem: Dell 82801IR/IO/IH (ICH9R/DO/DH) 6 port SATA 
Controller [AHCI mode]
         Flags: bus master, 66MHz, medium devsel, latency 0, IRQ 18
         I/O ports at fe00 [size=8]
         I/O ports at fe10 [size=4]
         I/O ports at fe20 [size=8]
         I/O ports at fe30 [size=4]
         I/O ports at fec0 [size=32]
         Memory at f0200000 (32-bit, non-prefetchable) [size=2K]
         Capabilities: [80] MSI: Enable- Count=1/16 Maskable- 64bit-
         Capabilities: [70] Power Management version 3
         Capabilities: [a8] SATA HBA v1.0
         Capabilities: [b0] PCI Advanced Features
         Kernel driver in use: ahci

The only relevant clue I can find is in dmesg where it's identifying 
SATA ports:

[    2.322175] ahci 0000:00:1f.2: AHCI 0001.0200 32 slots 6 ports 3 Gbps 
0x2f impl SATA mode
[    2.322185] ahci 0000:00:1f.2: flags: 64bit ncq sntf pm led clo pmp 
pio slum part ccc ems sxs
[    2.340945] fbcon: inteldrmfb (fb0) is primary device
[    2.400466] scsi host0: ahci
[    2.400564] scsi host1: ahci
[    2.400659] scsi host2: ahci
[    2.400750] scsi host3: ahci
[    2.400842] scsi host4: ahci
[    2.400929] scsi host5: ahci
[    2.400974] ata1: SATA max UDMA/133 abar m2048 at 0xf0200000 port 
0xf0200100 irq 18
[    2.400976] ata2: SATA max UDMA/133 abar m2048 at 0xf0200000 port 
0xf0200180 irq 18
[    2.400977] ata3: SATA max UDMA/133 abar m2048 at 0xf0200000 port 
0xf0200200 irq 18
[    2.400979] ata4: SATA max UDMA/133 abar m2048 at 0xf0200000 port 
0xf0200280 irq 18
[    2.400979] ata5: DUMMY
[    2.400981] ata6: SATA max UDMA/133 abar m2048 at 0xf0200000 port 
0xf0200380 irq 18

It doesn't appear to be enumerating ports that don't have anything 
plugged in, because there are 10 total SATA ports.  I don't have any 
idea what "ata5: DUMMY" is telling me. There's only two drives plugged 
into the Intel controller on the motherboard—the boot drive and the CD 
drive.  The other four (5 hard drives total) are plugged into a VIA 
controller on the PCIE bus.  If it weren't seeing both controllers, I'd 
have hard drives missing as well, and I don't.

I've never had such pain getting a CD/DVD drive to work.  Obviously I'm 
missing something, but I've run out of ideas.

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