[rhelv6-list] Turn off/disable ATA device on running system

[chandler]

Hi all,
	We have a server running RHEL6 with kernel 2.6.32-573.18.1.el6.x86_64.
 I keep seeing "ata5.00: qc timeout (cmd 0xa0)" et. al. every few
minutes.  According to dmesg ata5 is the optical drive, which we don't
use right now and haven't been using.  The messages just started
yesterday.  We need to keep the system running for now, so i was
wondering if there was a way to tell the kernel to stop caring about it?
 Effectively disable it, remove it from the list of devices?
Thanks

PS if anyone can decipher what is going on with the drive,
kernel: ata5.00: qc timeout (cmd 0xa0)
kernel: ata5.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
kernel: sr 4:0:0:0: CDB: Test Unit Ready: 00 00 00 00 00 00
kernel: ata5.00: cmd a0/00:00:00:00:00/00:00:00:00:00/a0 tag 17
kernel:         res 51/20:03:00:00:00/00:00:00:00:00/a0 Emask 0x5 (timeout)
kernel: ata5.00: status: { DRDY ERR }
kernel: ata5: link is slow to respond, please be patient (ready=0)
kernel: ata5: device not ready (errno=-16), forcing hardreset
kernel: ata5: soft resetting link
kernel: ata5.00: configured for PIO0
kernel: ata5: EH complete