[PATCH 10/10] ata: libata_eh: Add debug messages to ata_eh_link_set_lpm()

[Damien Le Moal <dlemoal@kernel.org>]

To facilitate field debugging of link power management related issues,
add a debug message to ata_eh_link_set_lpm() to easily track LPM policy
changes done from EH context, that is, during device scan and
revalidation, error handling, and when a policy change is issued through
a host sysfs link_power_management_policy attribute.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
---
 drivers/ata/libata-eh.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 7f5d13f9ca73..7134a4ff6535 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -2140,6 +2140,9 @@ static int ata_eh_link_set_lpm(struct ata_link *link,
 	if (WARN_ON_ONCE(policy == ATA_LPM_UNKNOWN))
 		return 0;
 
+	ata_link_dbg(link, "Set LPM policy: %d -> %d\n",
+		     old_policy, policy);
+
 	/*
 	 * DIPM is enabled only for ATA_LPM_MIN_POWER,
 	 * ATA_LPM_MIN_POWER_WITH_PARTIAL, and ATA_LPM_MED_POWER_WITH_DIPM, as
-- 
2.50.0