AHCI Spec shows that the PxSCTL.IPM field in each port must be programmed to disallow device initiated LPM requests when HBA can not support transitions to the LPM state. The current LPM driver has no restrictions on LPM transitions when enabling device initiated LPM. Signed-off-by: LeoLiu-oc <LeoLiu-oc@zhaoxin.com> ---  drivers/ata/libata-sata.c | 11 ++++++++++-  1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c index c16423e44..7e1296b55 100644 --- a/drivers/ata/libata-sata.c +++ b/drivers/ata/libata-sata.c @@ -394,9 +394,18 @@ int sata_link_scr_lpm(struct ata_link *link, enum ata_lpm_policy policy,      case ATA_LPM_MED_POWER_WITH_DIPM:      case ATA_LPM_MIN_POWER_WITH_PARTIAL:      case ATA_LPM_MIN_POWER: -        if (ata_link_nr_enabled(link) > 0) +        if (ata_link_nr_enabled(link) > 0) {              /* no restrictions on LPM transitions */              scontrol &= ~(0x7 << 8); +            /* if Host does not support partial, then disallows it, +             * the same for slumber +             */ +            if (!(link->ap->host->flags & ATA_HOST_PART)) +                scontrol |= (0x1 << 8); + +            if (!(link->ap->host->flags & ATA_HOST_SSC)) +                scontrol |= (0x2 << 8); +        }          else {              /* empty port, power off */              scontrol &= ~0xf; -- 2.20.1