libata: Add ATA_HORKAGE_NO_NCQ_ON_ATI for Samsung 860 and 870 SSD.

commit 7a8526a5cd51cf5f070310c6c37dd7293334ac49 upstream.

Many users are reporting that the Samsung 860 and 870 SSD are having
various issues when combined with AMD/ATI (vendor ID 0x1002)  SATA
controllers and only completely disabling NCQ helps to avoid these

Always disabling NCQ for Samsung 860/870 SSDs regardless of the host
SATA adapter vendor will cause I/O performance degradation with well
behaved adapters. To limit the performance impact to ATI adapters,
introduce the ATA_HORKAGE_NO_NCQ_ON_ATI flag to force disable NCQ
only for these adapters.

Also, two libata.force parameters (noncqati and ncqati) are introduced
to disable and enable the NCQ for the system which equipped with ATI
SATA adapter and Samsung 860 and 870 SSDs. The user can determine NCQ
function to be enabled or disabled according to the demand.

After verifying the chipset from the user reports, the issue appears
on AMD/ATI SB7x0/SB8x0/SB9x0 SATA Controllers and does not appear on
recent AMD SATA adapters. The vendor ID of ATI should be 0x1002.
Therefore, ATA_HORKAGE_NO_NCQ_ON_AMD was modified to

Signed-off-by: Kate Hsuan <>
Reviewed-by: Hans de Goede <>
Reviewed-by: Martin K. Petersen <>
Signed-off-by: Jens Axboe <>
Cc: Krzysztof Olędzki <>
Signed-off-by: Greg Kroah-Hartman <>
2 files changed