From: Anssi Hannula <anssi.hannula@xxxxxxxxxx> commit 455561fb618fde40558776b5b8435f9420f335db upstream. The TX queue seems to be implicitly flushed by the hardware during bus-off or bus-off recovery, but the driver does not reset the TX bookkeeping. Despite not resetting TX bookkeeping the driver still re-enables TX queue unconditionally, leading to "cannot find free context" / NETDEV_TX_BUSY errors if the TX queue was full at bus-off time. Fix that by resetting TX bookkeeping on CAN restart. Tested with 0bfd:0124 Kvaser Mini PCI Express 2xHS FW 4.18.778. Cc: stable@xxxxxxxxxxxxxxx Fixes: 080f40a6fa28 ("can: kvaser_usb: Add support for Kvaser CAN/USB devices") Tested-by: Jimmy Assarsson <extja@xxxxxxxxxx> Signed-off-by: Anssi Hannula <anssi.hannula@xxxxxxxxxx> Signed-off-by: Jimmy Assarsson <extja@xxxxxxxxxx> Link: https://lore.kernel.org/all/20221010150829.199676-4-extja@xxxxxxxxxx Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/can/usb/kvaser_usb/kvaser_usb.h | 2 ++ drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c | 2 +- drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c | 2 ++ 3 files changed, 5 insertions(+), 1 deletion(-) --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb.h +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb.h @@ -177,6 +177,8 @@ struct kvaser_usb_dev_cfg { extern const struct kvaser_usb_dev_ops kvaser_usb_hydra_dev_ops; extern const struct kvaser_usb_dev_ops kvaser_usb_leaf_dev_ops; +void kvaser_usb_unlink_tx_urbs(struct kvaser_usb_net_priv *priv); + int kvaser_usb_recv_cmd(const struct kvaser_usb *dev, void *cmd, int len, int *actual_len); --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c @@ -476,7 +476,7 @@ static void kvaser_usb_reset_tx_urb_cont /* This method might sleep. Do not call it in the atomic context * of URB completions. */ -static void kvaser_usb_unlink_tx_urbs(struct kvaser_usb_net_priv *priv) +void kvaser_usb_unlink_tx_urbs(struct kvaser_usb_net_priv *priv) { usb_kill_anchored_urbs(&priv->tx_submitted); kvaser_usb_reset_tx_urb_contexts(priv); --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c @@ -1425,6 +1425,8 @@ static int kvaser_usb_leaf_set_mode(stru switch (mode) { case CAN_MODE_START: + kvaser_usb_unlink_tx_urbs(priv); + err = kvaser_usb_leaf_simple_cmd_async(priv, CMD_START_CHIP); if (err) return err;