ata: libata-core: Reduce the number of messages signaling broken LPM

ata_dev_config_lpm() prints the message "LPM support broken, forcing
max_power" for devices that have the ATA_QUIRK_NOLPM quirk flag set.
This messages is repeated for every device revalidation, which is not
necessary, but also erroneously printed for devices without a broken LPM
support when connected to a port that does not support LPM (e.g. because
the port is an external one with hotplug capability).

Since in all cases the device port target_lpm_policy is set to
ATA_LPM_MAX_POWER, avoid the "LPM broken" message repetition and
erroneous output by generating it only if the port target_lpm_policy is
not already set to ATA_LPM_MAX_POWER.

This change will suppress the "LPM broken" message for genuine cases of
a device having broken LPM if the initial LPM policy is set to
ATA_LPM_MAX_POWER through CONFIG_SATA_MOBILE_LPM_POLICY. This is not a
problem as the ATA_LPM_MAX_POWER policy implies that LPM is disabled and
unused, which is safe for devices with broken LPM.

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/20250701125321.69496-10-dlemoal@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 4619e66ae100c428a04c989a46b22ffdbd736f90..7f6cebe61b33736351108a9ac9c80012edac9f8f 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2819,7 +2819,8 @@ static void ata_dev_config_lpm(struct ata_device *dev)
                        dev->quirks |= ATA_QUIRK_NOLPM;
        }
 
-       if (dev->quirks & ATA_QUIRK_NOLPM) {
+       if (dev->quirks & ATA_QUIRK_NOLPM &&
+           ap->target_lpm_policy != ATA_LPM_MAX_POWER) {
                ata_dev_warn(dev, "LPM support broken, forcing max_power\n");
                ap->target_lpm_policy = ATA_LPM_MAX_POWER;
        }