From: Anssi Hannula anssi.hannula@bitwise.fi

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@vger.kernel.org Fixes: 080f40a6fa28 ("can: kvaser_usb: Add support for Kvaser CAN/USB devices") Tested-by: Jimmy Assarsson extja@kvaser.com Signed-off-by: Anssi Hannula anssi.hannula@bitwise.fi Signed-off-by: Jimmy Assarsson extja@kvaser.com Link: https://lore.kernel.org/all/20221010150829.199676-4-extja@kvaser.com Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de --- 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(-)

diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb.h b/drivers/net/can/usb/kvaser_usb/kvaser_usb.h index 841da29cef93..f6c0938027ec 100644 --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb.h +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb.h @@ -178,6 +178,8 @@ 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);

diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c index c2bce6773adc..e91648ed7386 100644 --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c @@ -477,7 +477,7 @@ static void kvaser_usb_reset_tx_urb_contexts(struct kvaser_usb_net_priv *priv) /* 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); diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c index 8e11cda85624..59c220ef3049 100644 --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c @@ -1426,6 +1426,8 @@ static int kvaser_usb_leaf_set_mode(struct net_device *netdev,

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;