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ata: ahci: Disable DIPM if host lacks support

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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@kernel.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de.>
Link: https://lore.kernel.org/r/20250701125321.69496-7-dlemoal@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>
This commit is contained in:
Damien Le Moal
2025-07-01 21:53:17 +09:00
committed by Niklas Cassel
parent 413e800cad
commit f7870e8d34
1 changed files with 7 additions and 0 deletions
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7
drivers/ata/ahci.c
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@@ -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) &&