Messages in this thread | | | Date | Mon, 02 Jun 2014 16:43:33 +0200 | From | Michal Privoznik <> | Subject | Re: [PATCH] net-sysfs: Report link speed as signed integer |
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On 02.06.2014 16:35, Jiri Pirko wrote: > Mon, Jun 02, 2014 at 04:25:15PM CEST, mprivozn@redhat.com wrote: >> The link speed is available at /sys/class/net/$nic/speed. >> However, the speed is printed in unsigned integer format. This >> makes userspace applications read an incorrect value (which >> moreover changes through several architectures) while in fact >> '-1' should be reported. >> >> Before the change: >> # cat /sys/class/net/eth0/speed >> 4294967295 >> >> After the change: >> # cat /sys/class/net/eth0/speed >> -1 >> >> Signed-off-by: Michal Privoznik <mprivozn@redhat.com> >> --- >> net/core/net-sysfs.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c >> index 1cac29e..99afdea 100644 >> --- a/net/core/net-sysfs.c >> +++ b/net/core/net-sysfs.c >> @@ -173,7 +173,7 @@ static ssize_t speed_show(struct device *dev, >> if (netif_running(netdev)) { >> struct ethtool_cmd cmd; >> if (!__ethtool_get_settings(netdev, &cmd)) >> - ret = sprintf(buf, fmt_udec, ethtool_cmd_speed(&cmd)); >> + ret = sprintf(buf, fmt_dec, ethtool_cmd_speed(&cmd)); > > I wonder why this should be signed. What -1 means? What driver reports > this?
This is e1000e. It seems like a default value. From e1000_get_settings() in drivers/net/ethernet/intel/e1000e/ethtool.c:
speed = -1; ecmd->duplex = -1;
if (netif_running(netdev)) { if (netif_carrier_ok(netdev)) { speed = adapter->link_speed; ecmd->duplex = adapter->link_duplex - 1; } } else if (!pm_runtime_suspended(netdev->dev.parent)) { ... }
ethtool_cmd_speed_set(ecmd, speed);
If I unplug the cord, NIC is nor running nor runtime suspended.
Michal
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