[CentOS] Issue with dvd/cdrom drive

[Pete Biggs]

> 
> [    2.183682] ata4: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
> [    2.183825] ata3: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
> [    7.183893] ata3.00: qc timeout (cmd 0xec)
> [    7.183908] ata3.00: failed to IDENTIFY (I/O error, err_mask=0x4)
> [    7.183960] ata4.00: qc timeout (cmd 0xa1)
> [    7.183974] ata4.00: failed to IDENTIFY (I/O error, err_mask=0x4)
> [    7.488894] ata3: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
> [    7.488931] ata4: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
> [   17.488919] ata3.00: qc timeout (cmd 0xec)
> [   17.488934] ata3.00: failed to IDENTIFY (I/O error, err_mask=0x4)
> [   17.488942] ata3: limiting SATA link speed to 3.0 Gbps
> [   17.488964] ata4.00: qc timeout (cmd 0xa1)
> [   17.488979] ata4.00: failed to IDENTIFY (I/O error, err_mask=0x4)
> [   17.793923] ata3: SATA link up 3.0 Gbps (SStatus 123 SControl 320)
> [   17.794894] ata4: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
> [   47.794008] ata3.00: qc timeout (cmd 0xec)
> [   47.794023] ata3.00: failed to IDENTIFY (I/O error, err_mask=0x4)
> [   47.794880] ata4.00: qc timeout (cmd 0xa1)
> [   47.794897] ata4.00: failed to IDENTIFY (I/O error, err_mask=0x4)
> [   48.099012] ata3: SATA link up 3.0 Gbps (SStatus 123 SControl 320)
> [   48.099884] ata4: SATA link up 1.5 Gbps (SStatus 113 SControl 300)

So lots of errors there - the "failed to IDENTIFY" means there is
something present but it's not responding to the commands.  These sorts
of things are almost always down to the SATA BIOS settings or buggy
SATA hardware. Make sure the BIOS has the SATA settings as AHCI and if
that doesn't improve things then set "noapic" and/or "acpi=off" on the
kernel command line.

Googling for "qc timeout (cmd 0xec)" gives lots of hits.

Be warned though, changing the SATA BIOS settings may have an adverse
affect on the Windows install - it may fail to recognise your disks.

P.