FAILED: patch "[PATCH] can: kvaser_usb_leaf: Fix TX queue out of sync after restart" failed to apply to 4.9-stable tree

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

Possible dependencies:

455561fb618f ("can: kvaser_usb_leaf: Fix TX queue out of sync after restart") 7259124eac7d ("can: kvaser_usb: Split driver into kvaser_usb_core.c and kvaser_usb_leaf.c") e0543f2479f8 ("can: kvaser_usb: Add SPDX GPL-2.0 license identifier") 2b049c150080 ("can: kvaser_usb: Fix typos")
6ba0b9294bca ("can: kvaser_usb: Improve logging messages")
7c4780146177 ("can: kvaser_usb: Refactor kvaser_usb_init_one()")
99ce1bc17462 ("can: kvaser_usb: Refactor kvaser_usb_get_endpoints()") 0e30619fd6fa ("can: kvaser_usb: Add pointer to struct usb_interface into struct kvaser_usb") 75d2b4c3e399 ("can: kvaser_usb: Replace USB timeout constants with one define") f741f938556d ("can: kvaser_usb: Rename message/msg to command/cmd") 237572220121 ("can: kvaser_usb: Remove unused commands and defines") deaa1c984be7 ("can: kvaser_usb: Remove unnecessary return")
ffbdd9172ee2 ("can: usb: Kconfig/Makefile: sort alphabetically")
6ee00865ffe4 ("can: kvaser_usb: Increase correct stats counter in kvaser_usb_rx_can_msg()") 6aa8d5945502 ("can: kvaser_usb: cancel urb on -EPIPE and -EPROTO") 8bd13bd522ff ("can: kvaser_usb: ratelimit errors if incomplete messages are received") e84f44eb5523 ("can: kvaser_usb: Fix comparison bug in kvaser_usb_read_bulk_callback()") 435019b48033 ("can: kvaser_usb: free buf in error paths")
e1d2d1329a57 ("can: kvaser_usb: Ignore CMD_FLUSH_QUEUE_REPLY messages") 8f65a923e6b6 ("can: kvaser_usb: Correct return value in printout")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 455561fb618fde40558776b5b8435f9420f335db Mon Sep 17 00:00:00 2001
From: Anssi Hannula <[email protected]>
Date: Mon, 10 Oct 2022 17:08:28 +0200
Subject: [PATCH] can: kvaser_usb_leaf: Fix TX queue out of sync after restart

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.

index 841da29cef93..f6c0938027ec 100644
@@ -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);
 

index c2bce6773adc..e91648ed7386 100644
@@ -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);

index 8e11cda85624..59c220ef3049 100644
@@ -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;