summaryrefslogtreecommitdiff
path: root/net/ethtool
diff options
context:
space:
mode:
authorJohannes Berg <johannes.berg@intel.com>2023-12-04 23:47:07 +0300
committerJakub Kicinski <kuba@kernel.org>2023-12-06 07:16:45 +0300
commitfacd15dfd69122042502d99ab8c9f888b48ee994 (patch)
tree1e84133ba27f60f62134588c7cce46dc73badc31 /net/ethtool
parentfaf4cf7495431d396147d5c73a84ccfddc458c9d (diff)
downloadlinux-facd15dfd69122042502d99ab8c9f888b48ee994.tar.xz
net: core: synchronize link-watch when carrier is queried
There are multiple ways to query for the carrier state: through rtnetlink, sysfs, and (possibly) ethtool. Synchronize linkwatch work before these operations so that we don't have a situation where userspace queries the carrier state between the driver's carrier off->on transition and linkwatch running and expects it to work, when really (at least) TX cannot work until linkwatch has run. I previously posted a longer explanation of how this applies to wireless [1] but with this wireless can simply query the state before sending data, to ensure the kernel is ready for it. [1] https://lore.kernel.org/all/346b21d87c69f817ea3c37caceb34f1f56255884.camel@sipsolutions.net/ Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://lore.kernel.org/r/20231204214706.303c62768415.I1caedccae72ee5a45c9085c5eb49c145ce1c0dd5@changeid Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ethtool')
-rw-r--r--net/ethtool/ioctl.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 0b0ce4f81c01..a977f8903467 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -58,6 +58,9 @@ static struct devlink *netdev_to_devlink_get(struct net_device *dev)
u32 ethtool_op_get_link(struct net_device *dev)
{
+ /* Synchronize carrier state with link watch, see also rtnl_getlink() */
+ linkwatch_sync_dev(dev);
+
return netif_carrier_ok(dev) ? 1 : 0;
}
EXPORT_SYMBOL(ethtool_op_get_link);