libata: add whitelist for devices with known good pata-sata bridges

libata currently imposes a UDMA5 max transfer rate and 200 sector max
transfer size for SATA devices that sit behind a pata-sata bridge. Lots
of devices have known good bridges that don't need this limit applied.
The MTRON SSD disks are such devices. Transfer rates are increased by
20-30% with the restriction removed.

So add a "blacklist" entry for the MTRON devices, with a flag indicating
that the bridge is known good.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 8824c8d..82af701 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2158,6 +2158,10 @@ retry:
 static inline u8 ata_dev_knobble(struct ata_device *dev)
 {
 	struct ata_port *ap = dev->link->ap;
+
+	if (ata_dev_blacklisted(dev) & ATA_HORKAGE_BRIDGE_OK)
+		return 0;
+
 	return ((ap->cbl == ATA_CBL_SATA) && (!ata_id_is_sata(dev->id)));
 }
 
@@ -4062,6 +4066,9 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = {
 	{ "TSSTcorp CDDVDW SH-S202N", "SB00",	  ATA_HORKAGE_IVB, },
 	{ "TSSTcorp CDDVDW SH-S202N", "SB01",	  ATA_HORKAGE_IVB, },
 
+	/* Devices that do not need bridging limits applied */
+	{ "MTRON MSP-SATA*",		NULL,	ATA_HORKAGE_BRIDGE_OK, },
+
 	/* End Marker */
 	{ }
 };