The AHCI specification version 1.3.1 section 8.3.1.4 (Software
Requirements and Precedence) states that:
If CAP.SSC or CAP.PSC is cleared to ‘0’, software should disable
device-initiated power management by issuing the appropriate SET
FEATURES command to the device.
To satisfy this constraint and force ata_dev_configure to disable the
device DIPM feature, modify ahci_update_initial_lpm_policy() to set the
ATA_FLAG_NO_DIPM flag on ports that have a host with either the
ATA_HOST_NO_PART flag set or the ATA_HOST_NO_SSC flag set.
Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
---
drivers/ata/ahci.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 1b4151d95888..0760fa47d90e 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1780,6 +1780,13 @@ static void ahci_update_initial_lpm_policy(struct ata_port *ap)
return;
}
+ /* If no Partial or no Slumber, we cannot support DIPM. */
+ if ((ap->host->flags & ATA_HOST_NO_PART) ||
+ (ap->host->flags & ATA_HOST_NO_SSC)) {
+ ata_port_dbg(ap, "Host does not support DIPM\n");
+ ap->flags |= ATA_FLAG_NO_DIPM;
+ }
+
/* If no LPM states are supported by the HBA, do not bother with LPM */
if ((ap->host->flags & ATA_HOST_NO_PART) &&
(ap->host->flags & ATA_HOST_NO_SSC) &&
--
2.50.0
