netdevsim: set the carrier when the device goes up

Bringing a linked netdevsim device down and then up causes communication
failure because both interfaces lack carrier. Basically a ifdown/ifup on
the interface make the link broken.

Commit 3762ec05a9 ("netdevsim: add NAPI support") added supported
for NAPI, calling netif_carrier_off() in nsim_stop(). This patch
re-enables the carrier symmetrically on nsim_open(), in case the device
is linked and the peer is up.

Signed-off-by: Breno Leitao <leitao@debian.org>
Fixes: 3762ec05a9 ("netdevsim: add NAPI support")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20251014-netdevsim_fix-v2-1-53b40590dae1@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Breno Leitao
2025-10-14 02:17:25 -07:00
committed by Jakub Kicinski
parent cf51d617c3
commit 1a8fed52f7

View File

@@ -545,6 +545,7 @@ static void nsim_enable_napi(struct netdevsim *ns)
static int nsim_open(struct net_device *dev)
{
struct netdevsim *ns = netdev_priv(dev);
struct netdevsim *peer;
int err;
netdev_assert_locked(dev);
@@ -555,6 +556,12 @@ static int nsim_open(struct net_device *dev)
nsim_enable_napi(ns);
peer = rtnl_dereference(ns->peer);
if (peer && netif_running(peer->netdev)) {
netif_carrier_on(dev);
netif_carrier_on(peer->netdev);
}
return 0;
}