On my system (2.6.23-rc9) I have Serial-ATA DVD/RW drive connected to sata_sil controller:
[ 96.858283] ata6: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
[ 97.012480] ata6.00: ATAPI: TSSTcorpCD/DVDW SH-S183A, SB02, max UDMA/33
[ 97.012482] ata6.00: applying bridge limits
[ 97.169126] ata6.00: configured for UDMA/33
Sometimes when there is a problem with CD or DVD disk controller shutdowns drive:
[53560.095573] cdrom: sr0: mrw address space DMA selected
[53561.001946] ISO 9660 Extensions: Microsoft Joliet Level 3
[53561.002777] ISOFS: changing to secondary root
[53621.380238] ata6.00: exception Emask 0x10 SAct 0x0 SErr 0x90000 action 0x2
[53621.380249] ata6.00: cmd a0/00:00:00:00:20/00:00:00:00:00/a0 tag 0 cdb 0x0 data 0
[53621.380252] res 51/60:03:00:00:00/00:00:00:00:00/a0 Emask 0x10 (ATA bus error)
[53621.380263] ata6: hard resetting port
[53623.783961] ata6: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
[53642.595278] ata6.00: qc timeout (cmd 0xa1)
[53642.595285] ata6.00: failed to IDENTIFY (I/O error, err_mask=0x4)
[53642.595288] ata6.00: revalidation failed (errno=-5)
[53642.595292] ata6: failed to recover some devices, retrying in 5 secs
[53645.092046] ata6: hard resetting port
[53646.193870] ata6: SATA link down (SStatus 1 SControl 310)
[53646.193881] ata6.00: limiting speed to UDMA/25:PIO3
[53646.193884] ata6: failed to recover some devices, retrying in 5 secs
[53648.690501] ata6: hard resetting port
[53649.792323] ata6: SATA link down (SStatus 1 SControl 310)
[53649.792333] ata6.00: disabled
[53650.042442] ata6: EH pending after completion, repeating EH (cnt=4)
[53650.042459] ata6: EH complete
[53650.042512] sr 6:0:0:0: rejecting I/O to offline device
[53650.042518] sr 6:0:0:0: rejecting I/O to offline device
[53650.042522] sr 6:0:0:0: rejecting I/O to offline device
[53650.042536] sr 6:0:0:0: rejecting I/O to offline device
[53650.042632] ata6.00: detaching (SCSI 6:0:0:0)
I wonder is there a way to re-enable ata6.00 in other way then power down/power up whole machine because it looks like reboot is not a way to get it working again.