I'm running into the same issue reported here:
<http://readlist.com/lists/vger.kernel.org/linux-kernel/72/361184.html>
I am using the ata_piix module. If I read the docs correctly, I should be able to use ahci as well; I need to rebuild the kernel though (debian insists on putting ata_piix into the initrd....)
dionysus:~# ls -l /sys/block/sd[abcde]/device/queue_depth
-r--r--r-- 1 root root 4096 2007-09-01 06:00 /sys/block/sda/device/queue_depth
-r--r--r-- 1 root root 4096 2007-09-01 06:00 /sys/block/sdb/device/queue_depth
-r--r--r-- 1 root root 4096 2007-09-01 06:00 /sys/block/sdc/device/queue_depth
-r--r--r-- 1 root root 4096 2007-09-01 06:00 /sys/block/sdd/device/queue_depth
-r--r--r-- 1 root root 4096 2007-09-01 06:00 /sys/block/sde/device/queue_depth
If I change the perms to rw, I get an Input/Output error. AFAICT, the drives support queueing, but it's disabled.