[B.A.T.M.A.N.] [PATCH] batman-adv: disable ethtool link speed detection when auto negotiation off
If link auto-negotiation is disabled the exported link speed can not be relied on.
Signed-off-by: Marek Lindner mareklindner@neomailbox.ch --- net/batman-adv/bat_v_elp.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c index 28687493..fd6fe847 100644 --- a/net/batman-adv/bat_v_elp.c +++ b/net/batman-adv/bat_v_elp.c @@ -127,7 +127,11 @@ static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh) rtnl_lock(); ret = __ethtool_get_link_ksettings(hard_iface->net_dev, &link_settings); rtnl_unlock(); - if (ret == 0) { + + /* If link auto-negotiation is disabled the exported link speed can + * not be relied on. + */ + if (ret == 0 && link_settings.base.autoneg == AUTONEG_ENABLE) { /* link characteristics might change over time */ if (link_settings.base.duplex == DUPLEX_FULL) hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX;
On 13/05/18 06:02, Marek Lindner wrote:
If link auto-negotiation is disabled the exported link speed can not be relied on.
Signed-off-by: Marek Lindner mareklindner@neomailbox.ch
Acked-by: Antonio Quartulli a@unstable.cc
Hi Sven,
thanks for your comment.
On 13/05/18 14:56, Sven Eckelmann wrote:
On Sonntag, 13. Mai 2018 00:02:23 CEST Marek Lindner wrote:
If link auto-negotiation is disabled the exported link speed can not be relied on.
Why is a manual set speed less worth than a auto-configured one?
if the user wants to configure a "default throughput" for the interface, he can always use the default_throughput knob in batman-adv.
The problem with autonegotiation disabled is that the advertised speed is likely to be a random number set by default by the driver.
For example, some people in the freifunk community have tested this patch because they wanted to see how the tp_meter would perform on VPN links. Unfortunately the tun.ko module sets 10Mbps/AUTONEG_DISABLE as default settings.
From there we thought that, after all, if the autonegotiation is disabled, we should just assume that the speed is likely to be bogus and it's better to measure it.
Does it make sense?
Cheers,
On Sonntag, 13. Mai 2018 11:19:52 CEST Antonio Quartulli wrote:
Hi Sven,
thanks for your comment.
On 13/05/18 14:56, Sven Eckelmann wrote:
On Sonntag, 13. Mai 2018 00:02:23 CEST Marek Lindner wrote:
If link auto-negotiation is disabled the exported link speed can not be relied on.
Why is a manual set speed less worth than a auto-configured one?
[...]
For example, some people in the freifunk community have tested this patch because they wanted to see how the tp_meter would perform on VPN links. Unfortunately the tun.ko module sets 10Mbps/AUTONEG_DISABLE as default settings.
From there we thought that, after all, if the autonegotiation is disabled, we should just assume that the speed is likely to be bogus and it's better to measure it.
[...]
I saw the discussion with Matthias. But nothing about that wasn't mentioned in the commit message. Looks like Marek already addresses these things and just has to submit the patch again.
And he should not forget your Acked-by (in case it still stands).
Kind regards, Sven
Name of failed tests ====================
ecsv/pu -------
* sparse linux-3.18 cfg: BLA=n DAT=n DEBUGFS=y DEBUG=y NC=y MCAST=y BATMAN_V=y * sparse linux-3.18 cfg: BLA=y DAT=n DEBUGFS=y DEBUG=n NC=n MCAST=n BATMAN_V=y * sparse linux-4.2 cfg: BLA=y DAT=n DEBUGFS=n DEBUG=n NC=n MCAST=n BATMAN_V=y * sparse linux-4.4 cfg: BLA=n DAT=n DEBUGFS=n DEBUG=n NC=n MCAST=y BATMAN_V=y * sparse linux-4.4 cfg: BLA=y DAT=n DEBUGFS=n DEBUG=n NC=n MCAST=n BATMAN_V=y * sparse linux-4.4 cfg: BLA=y DAT=n DEBUGFS=y DEBUG=y NC=n MCAST=y BATMAN_V=y
Output of different failed tests ================================
ecsv/pu: sparse linux-4.2 cfg: BLA=y DAT=n DEBUGFS=n DEBUG=n NC=n MCAST=n BATMAN_V=y ---------------------------------------------------------------------------
/home/build_test/build_env/tmp.Z3XNaFEJS1/build/net/batman-adv/bat_v_elp.c:134:43: error: no member 'autoneg' in struct <unnamed> /home/build_test/build_env/tmp.Z3XNaFEJS1/build/net/batman-adv/bat_v_elp.c:134:43: warning: unknown expression (8 46) /home/build_test/build_env/tmp.Z3XNaFEJS1/build/net/batman-adv/bat_v_elp.c: In function ‘batadv_v_elp_get_throughput’: /home/build_test/build_env/tmp.Z3XNaFEJS1/build/net/batman-adv/bat_v_elp.c:134:36: error: ‘struct <anonymous>’ has no member named ‘autoneg’ if (ret == 0 && link_settings.base.autoneg == AUTONEG_ENABLE) { ^ make[3]: *** [/home/build_test/build_env/tmp.Z3XNaFEJS1/build/net/batman-adv/bat_v_elp.o] Error 1 make[2]: *** [/home/build_test/build_env/tmp.Z3XNaFEJS1/build/net/batman-adv] Error 2 make[1]: *** [_module_/home/build_test/build_env/tmp.Z3XNaFEJS1/build] Error 2 make: *** [all] Error 2
b.a.t.m.a.n@lists.open-mesh.org
-
Antonio Quartulli -
Marek Lindner -
Sven Eckelmann