[PATCH net v2] net: usbnet: Fix the wrong netif_carrier_on() call placement
From: Ammar Faizi <hidden>
Date: 2025-08-01 19:03:35
Also in:
linux-usb, lkml, stable
Subsystem:
networking drivers, the rest, usb "usbnet" driver framework, usb networking drivers · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Oliver Neukum
The commit in the Fixes tag breaks my laptop (found by git bisect). My home RJ45 LAN cable cannot connect after that commit. The call to netif_carrier_on() should be done when netif_carrier_ok() is false. Not when it's true. Because calling netif_carrier_on() when __LINK_STATE_NOCARRIER is not set actually does nothing. Cc: Armando Budianto <redacted> Cc: stable@vger.kernel.org Closes: https://lore.kernel.org/netdev/0752dee6-43d6-4e1f-81d2-4248142cccd2@gnuweeb.org (local) Fixes: 0d9cfc9b8cb1 ("net: usbnet: Avoid potential RCU stall on LINK_CHANGE event") Signed-off-by: Ammar Faizi <redacted> --- v2: - Rebase on top of the latest netdev/net tree. The previous patch was based on 0d9cfc9b8cb1. Line numbers have changed since then. drivers/net/usb/usbnet.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index a38ffbf4b3f0..a1827684b92c 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c@@ -1114,31 +1114,31 @@ static const struct ethtool_ops usbnet_ethtool_ops = { }; /*-------------------------------------------------------------------------*/ static void __handle_link_change(struct usbnet *dev) { if (!test_bit(EVENT_DEV_OPEN, &dev->flags)) return; if (!netif_carrier_ok(dev->net)) { + if (test_and_clear_bit(EVENT_LINK_CARRIER_ON, &dev->flags)) + netif_carrier_on(dev->net); + /* kill URBs for reading packets to save bus bandwidth */ unlink_urbs(dev, &dev->rxq); /* * tx_timeout will unlink URBs for sending packets and * tx queue is stopped by netcore after link becomes off */ } else { - if (test_and_clear_bit(EVENT_LINK_CARRIER_ON, &dev->flags)) - netif_carrier_on(dev->net); - /* submitting URBs for reading packets */ queue_work(system_bh_wq, &dev->bh_work); } /* hard_mtu or rx_urb_size may change during link change */ usbnet_update_max_qlen(dev); clear_bit(EVENT_LINK_CHANGE, &dev->flags); }
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Ammar Faizi