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>
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 @@
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 @@
{ "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 */
{ }
};
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 507f53e..f5441ed 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -372,6 +372,7 @@
ATA_HORKAGE_IPM = (1 << 7), /* Link PM problems */
ATA_HORKAGE_IVB = (1 << 8), /* cbl det validity bit bugs */
ATA_HORKAGE_STUCK_ERR = (1 << 9), /* stuck ERR on next PACKET */
+ ATA_HORKAGE_BRIDGE_OK = (1 << 10), /* no bridge limits */
/* DMA mask for user DMA control: User visible values; DO NOT
renumber */