diff options
Diffstat (limited to 'drivers/ata/libata-core.c')
| -rw-r--r-- | drivers/ata/libata-core.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 3c5965d56c4..9fbf0595f3d 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -2232,6 +2232,40 @@ retry: return rc; } +static int ata_do_link_spd_horkage(struct ata_device *dev) +{ + struct ata_link *plink = ata_dev_phys_link(dev); + u32 target, target_limit; + + if (!sata_scr_valid(plink)) + return 0; + + if (dev->horkage & ATA_HORKAGE_1_5_GBPS) + target = 1; + else + return 0; + + target_limit = (1 << target) - 1; + + /* if already on stricter limit, no need to push further */ + if (plink->sata_spd_limit <= target_limit) + return 0; + + plink->sata_spd_limit = target_limit; + + /* Request another EH round by returning -EAGAIN if link is + * going faster than the target speed. Forward progress is + * guaranteed by setting sata_spd_limit to target_limit above. + */ + if (plink->sata_spd > target) { + ata_dev_printk(dev, KERN_INFO, + "applying link speed limit horkage to %s\n", + sata_spd_string(target)); + return -EAGAIN; + } + return 0; +} + static inline u8 ata_dev_knobble(struct ata_device *dev) { struct ata_port *ap = dev->link->ap; @@ -2322,6 +2356,10 @@ int ata_dev_configure(struct ata_device *dev) return 0; } + rc = ata_do_link_spd_horkage(dev); + if (rc) + return rc; + /* let ACPI work its magic */ rc = ata_acpi_on_devcfg(dev); if (rc) @@ -4223,6 +4261,9 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = { /* Devices that do not need bridging limits applied */ { "MTRON MSP-SATA*", NULL, ATA_HORKAGE_BRIDGE_OK, }, + /* Devices which aren't very happy with higher link speeds */ + { "WD My Book", NULL, ATA_HORKAGE_1_5_GBPS, }, + /* End Marker */ { } }; |