netdev - [PATCH ethtool-next 8/8] sff-8636: Print Power set and Power override bits

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Message-Id: <20211123174102.3242294-9-idosch@idosch.org>
Date:   Tue, 23 Nov 2021 19:41:02 +0200
From:   Ido Schimmel <idosch@...sch.org>
To:     netdev@...r.kernel.org
Cc:     mkubecek@...e.cz, popadrian1996@...il.com, andrew@...n.ch,
        mlxsw@...dia.com, moshe@...dia.com,
        Ido Schimmel <idosch@...dia.com>
Subject: [PATCH ethtool-next 8/8] sff-8636: Print Power set and Power override bits

From: Ido Schimmel <idosch@...dia.com>

Print the SFF-8636 Power set and Power override bits when dumping EEPROM
contents via the '-m' option. They can be used to understand low power
mode enforcement by the host.

The 'SFF8636_LOW_PWR_MODE' define is renamed to 'SFF8636_LOW_PWR_SET' to
reflect its naming in the standard for QSFP+/QSFP28.

Example output:

 # ethtool -m swp13
 Identifier                                : 0x11 (QSFP28)
 ...
 Extended identifier description           : 5.0W max. Power consumption,  High Power Class (> 3.5 W) enabled
 Power set                                 : Off
 Power override                            : On
 ...
 Transmit avg optical power (Channel 1)    : 0.7633 mW / -1.17 dBm
 Transmit avg optical power (Channel 2)    : 0.7649 mW / -1.16 dBm
 Transmit avg optical power (Channel 3)    : 0.7696 mW / -1.14 dBm
 Transmit avg optical power (Channel 4)    : 0.7739 mW / -1.11 dBm
 Rcvr signal avg optical power(Channel 1)  : 0.9240 mW / -0.34 dBm
 Rcvr signal avg optical power(Channel 2)  : 0.9129 mW / -0.40 dBm
 Rcvr signal avg optical power(Channel 3)  : 0.9194 mW / -0.36 dBm
 Rcvr signal avg optical power(Channel 4)  : 0.8708 mW / -0.60 dBm

 # ethtool --set-module swp13 power-mode-policy auto

 # ethtool -m swp13
 Identifier                                : 0x11 (QSFP28)
 ...
 Extended identifier description           : 5.0W max. Power consumption,  High Power Class (> 3.5 W) not enabled
 Power set                                 : On
 Power override                            : On
 ...
 Transmit avg optical power (Channel 1)    : 0.0000 mW / -inf dBm
 Transmit avg optical power (Channel 2)    : 0.0000 mW / -inf dBm
 Transmit avg optical power (Channel 3)    : 0.0000 mW / -inf dBm
 Transmit avg optical power (Channel 4)    : 0.0000 mW / -inf dBm
 Rcvr signal avg optical power(Channel 1)  : 0.0000 mW / -inf dBm
 Rcvr signal avg optical power(Channel 2)  : 0.0000 mW / -inf dBm
 Rcvr signal avg optical power(Channel 3)  : 0.0000 mW / -inf dBm
 Rcvr signal avg optical power(Channel 4)  : 0.0000 mW / -inf dBm

 # ethtool --set-module swp13 power-mode-policy high

 # ethtool -m swp13
 Identifier                                : 0x11 (QSFP28)
 ...
 Extended identifier description           : 5.0W max. Power consumption,  High Power Class (> 3.5 W) enabled
 Power set                                 : Off
 Power override                            : On
 ...
 Transmit avg optical power (Channel 1)    : 0.7733 mW / -1.12 dBm
 Transmit avg optical power (Channel 2)    : 0.7754 mW / -1.10 dBm
 Transmit avg optical power (Channel 3)    : 0.7885 mW / -1.03 dBm
 Transmit avg optical power (Channel 4)    : 0.7886 mW / -1.03 dBm
 Rcvr signal avg optical power(Channel 1)  : 0.9248 mW / -0.34 dBm
 Rcvr signal avg optical power(Channel 2)  : 0.9129 mW / -0.40 dBm
 Rcvr signal avg optical power(Channel 3)  : 0.9187 mW / -0.37 dBm
 Rcvr signal avg optical power(Channel 4)  : 0.8785 mW / -0.56 dBm

In the above example, the LPMode signal is ignored (Power override is
always on) and low power mode is controlled via software only.

Signed-off-by: Ido Schimmel <idosch@...dia.com>
---
 qsfp.c | 6 ++++++
 qsfp.h | 2 +-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/qsfp.c b/qsfp.c
index b3c9e1516af9..57aac86bd5f6 100644
--- a/qsfp.c
+++ b/qsfp.c
@@ -268,6 +268,12 @@ static void sff8636_show_ext_identifier(const struct sff8636_memory_map *map)
 		printf(" High Power Class (> 3.5 W) enabled\n");
 	else
 		printf(" High Power Class (> 3.5 W) not enabled\n");
+	printf("\t%-41s : ", "Power set");
+	printf("%s\n", ONOFF(map->lower_memory[SFF8636_PWR_MODE_OFFSET] &
+			     SFF8636_LOW_PWR_SET));
+	printf("\t%-41s : ", "Power override");
+	printf("%s\n", ONOFF(map->lower_memory[SFF8636_PWR_MODE_OFFSET] &
+			     SFF8636_PWR_OVERRIDE));
 }
 
 static void sff8636_show_connector(const struct sff8636_memory_map *map)
diff --git a/qsfp.h b/qsfp.h
index 1d8f24b5cbc2..aabf09fdc623 100644
--- a/qsfp.h
+++ b/qsfp.h
@@ -180,7 +180,7 @@
 
 #define	SFF8636_PWR_MODE_OFFSET		0x5D
 #define	 SFF8636_HIGH_PWR_ENABLE		(1 << 2)
-#define	 SFF8636_LOW_PWR_MODE			(1 << 1)
+#define	 SFF8636_LOW_PWR_SET			(1 << 1)
 #define	 SFF8636_PWR_OVERRIDE			(1 << 0)
 
 #define	SFF8636_TX_APP_SELECT_4_OFFSET	0x5E
-- 
2.31.1