5.4-stable review patch. If anyone has any objections, please let me know.
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From: Ammar Faizi ammarfaizi2@gnuweeb.org
commit 8466d393700f9ccef68134d3349f4e0a087679b9 upstream.
The commit referenced in the Fixes tag causes usbnet to malfunction (identified via git bisect). Post-commit, my external RJ45 LAN cable fails to connect. Linus also reported the same issue after pulling that commit.
The code has a logic error: netif_carrier_on() is only called when the link is already on. Fix this by moving the netif_carrier_on() call outside the if-statement entirely. This ensures it is always called when EVENT_LINK_CARRIER_ON is set and properly clears it regardless of the link state.
Cc: stable@vger.kernel.org Cc: Armando Budianto sprite@gnuweeb.org Reviewed-by: Simon Horman horms@kernel.org Suggested-by: Linus Torvalds torvalds@linux-foundation.org Link: https://lore.kernel.org/all/CAHk-=wjqL4uF0MG_c8+xHX1Vv8==sPYQrtzbdA3kzi96284... Closes: https://lore.kernel.org/netdev/CAHk-=wjKh8X4PT_mU1kD4GQrbjivMfPn-_hXa6han_BT... Closes: https://lore.kernel.org/netdev/0752dee6-43d6-4e1f-81d2-4248142cccd2@gnuweeb.... Fixes: 0d9cfc9b8cb1 ("net: usbnet: Avoid potential RCU stall on LINK_CHANGE event") Signed-off-by: Ammar Faizi ammarfaizi2@gnuweeb.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/usb/usbnet.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -1097,6 +1097,9 @@ static void __handle_link_change(struct if (!test_bit(EVENT_DEV_OPEN, &dev->flags)) return;
+ if (test_and_clear_bit(EVENT_LINK_CARRIER_ON, &dev->flags)) + netif_carrier_on(dev->net); + if (!netif_carrier_ok(dev->net)) { /* kill URBs for reading packets to save bus bandwidth */ unlink_urbs(dev, &dev->rxq); @@ -1106,9 +1109,6 @@ static void __handle_link_change(struct * 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 */ tasklet_schedule(&dev->bh); }