From: "Paul Rolland" <rol@as2917.net>

With this applied, my machine has stopped all those painful messages.
dmesg now says :

root@riri:/Kernels# dmesg | grep LBA
ata1.00: 490234752 sectors, multi 0: LBA48 NCQ (not used)
ata2.00: 640 sectors, multi 1: LBA 
ata3.00: 490234752 sectors, multi 0: LBA48 NCQ (not used)

Signed-off-by: Paul Rolland <rol@as2917.net>
Acked-by: Alan Cox <alan@redhat.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/ata/libata-core.c |    2 ++
 1 file changed, 2 insertions(+)

diff -puN drivers/ata/libata-core.c~ata-ncq-is-broken-on-maxtor-6l250s0 drivers/ata/libata-core.c
--- a/drivers/ata/libata-core.c~ata-ncq-is-broken-on-maxtor-6l250s0
+++ a/drivers/ata/libata-core.c
@@ -3483,6 +3483,8 @@ static const struct ata_blacklist_entry 
         { "WDC WD740ADFD-00",   NULL,		ATA_HORKAGE_NONCQ },
 	/* http://thread.gmane.org/gmane.linux.ide/14907 */
 	{ "FUJITSU MHT2060BH",	NULL,		ATA_HORKAGE_NONCQ },
+	/* NCQ is broken */
+	{ "Maxtor 6L250S0",     "BANC1G10",     ATA_HORKAGE_NONCQ },
 
 	/* Devices with NCQ limits */
 
_