[PATCH 6.1 094/280] ata: libata-core: Introduce ata_dev_config_lpm()

Greg Kroah-Hartman
2026-02-04T15:10:18Z

From: Damien Le Moal <dlemoal@kernel.org>

[ Upstream commit d360121832d8a36871249271df5b9ff05f835f62 ]

If the port of a device does not support Device Initiated Power
Management (DIPM), that is, the port is flagged with ATA_FLAG_NO_DIPM,
the DIPM feature of a device should not be used. Though DIPM is disabled
by default on a device, the "Software Settings Preservation feature"
may keep DIPM enabled or DIPM may have been enabled by the system
firmware.

Introduce the function ata_dev_config_lpm() to always disable DIPM on a
device that supports this feature if the port of the device is flagged
with ATA_FLAG_NO_DIPM. ata_dev_config_lpm() is called from
ata_dev_configure(), ensuring that a device DIPM feature is disabled
when it cannot be used.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20250701125321.69496-2-dlemoal@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Stable-dep-of: c8c6fb886f57 ("ata: libata: Print features also for ATAPI devices")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/ata/libata-core.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 31c8156a4f3d3..1277b80726535 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2617,6 +2617,30 @@ static void ata_dev_config_cpr(struct ata_device *dev)
kfree(buf);
}

+/*
+ * Configure features related to link power management.
+ */
+static void ata_dev_config_lpm(struct ata_device *dev)
+{
+ struct ata_port *ap = dev->link->ap;
+ unsigned int err_mask;
+
+ /*
+ * Device Initiated Power Management (DIPM) is normally disabled by
+ * default on a device. However, DIPM may have been enabled and that
+ * setting kept even after COMRESET because of the Software Settings
+ * Preservation feature. So if the port does not support DIPM and the
+ * device does, disable DIPM on the device.
+ */
+ if (ap->flags & ATA_FLAG_NO_DIPM && ata_id_has_dipm(dev->id)) {
+ err_mask = ata_dev_set_feature(dev,
+ SETFEATURES_SATA_DISABLE, SATA_DIPM);
+ if (err_mask && err_mask != AC_ERR_DEV)
+ ata_dev_err(dev, "Disable DIPM failed, Emask 0x%x\n",
+ err_mask);
+ }
+}
+
static void ata_dev_print_features(struct ata_device *dev)
{
if (!(dev->flags & ATA_DFLAG_FEATURES_MASK) && !dev->cpr_log)
@@ -2785,6 +2809,7 @@ int ata_dev_configure(struct ata_device *dev)
ata_dev_config_chs(dev);
}

+ ata_dev_config_lpm(dev);
ata_dev_config_fua(dev);
ata_dev_config_devslp(dev);
ata_dev_config_sense_reporting(dev);
--
2.51.0