diff options
Diffstat (limited to 'drivers/ata/libata-core.c')
| -rw-r--r-- | drivers/ata/libata-core.c | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 3a1ec4e715ed..164c7d9514f9 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -2751,17 +2751,27 @@ int sata_down_spd_limit(struct ata_link *link) static int __sata_set_spd_needed(struct ata_link *link, u32 *scontrol) { - u32 spd, limit; + struct ata_link *host_link = &link->ap->link; + u32 limit, target, spd; - if (link->sata_spd_limit == UINT_MAX) - limit = 0; + limit = link->sata_spd_limit; + + /* Don't configure downstream link faster than upstream link. + * It doesn't speed up anything and some PMPs choke on such + * configuration. + */ + if (!ata_is_host_link(link) && host_link->sata_spd) + limit &= (1 << host_link->sata_spd) - 1; + + if (limit == UINT_MAX) + target = 0; else - limit = fls(link->sata_spd_limit); + target = fls(limit); spd = (*scontrol >> 4) & 0xf; - *scontrol = (*scontrol & ~0xf0) | ((limit & 0xf) << 4); + *scontrol = (*scontrol & ~0xf0) | ((target & 0xf) << 4); - return spd != limit; + return spd != target; } /** |