From 4456ed04ea44b800d691b18c14a68ec9894d2aca Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Sun, 7 Feb 2016 23:27:55 +0200 Subject: [PATCH] ethtool: future-proof interface for speed extensions Many virtual and not quite virtual devices allow any speed to be set through ethtool. In particular, this applies to the virtio-net devices. Document this fact to make sure people don't assume the enum lists all possible values. Reserve values greater than INT_MAX for future extension and to avoid conflict with SPEED_UNKNOWN. Signed-off-by: Michael S. Tsirkin Signed-off-by: David S. Miller --- include/uapi/linux/ethtool.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h index 5e0940dcbfe8..4345f80a2e33 100644 --- a/include/uapi/linux/ethtool.h +++ b/include/uapi/linux/ethtool.h @@ -31,7 +31,7 @@ * physical connectors and other link features that are * advertised through autonegotiation or enabled for * auto-detection. - * @speed: Low bits of the speed + * @speed: Low bits of the speed, 1Mb units, 0 to INT_MAX or SPEED_UNKNOWN * @duplex: Duplex mode; one of %DUPLEX_* * @port: Physical connector type; one of %PORT_* * @phy_address: MDIO address of PHY (transceiver); 0 or 255 if not @@ -47,7 +47,7 @@ * obsoleted by &struct ethtool_coalesce. Read-only; deprecated. * @maxrxpkt: Historically used to report RX IRQ coalescing; now * obsoleted by &struct ethtool_coalesce. Read-only; deprecated. - * @speed_hi: High bits of the speed + * @speed_hi: High bits of the speed, 1Mb units, 0 to INT_MAX or SPEED_UNKNOWN * @eth_tp_mdix: Ethernet twisted-pair MDI(-X) status; one of * %ETH_TP_MDI_*. If the status is unknown or not applicable, the * value will be %ETH_TP_MDI_INVALID. Read-only. @@ -1359,7 +1359,7 @@ enum ethtool_sfeatures_retval_bits { * it was forced up into this mode or autonegotiated. */ -/* The forced speed, 10Mb, 100Mb, gigabit, [2.5|5|10|20|25|40|50|56|100]GbE. */ +/* The forced speed, in units of 1Mb. All values 0 to INT_MAX are legal. */ #define SPEED_10 10 #define SPEED_100 100 #define SPEED_1000 1000