Commit abb86709 authored by Anssi Hannula's avatar Anssi Hannula Committed by Marc Kleine-Budde
Browse files

can: kvaser_usb_leaf: Ignore stale bus-off after start 



With 0bfd:0124 Kvaser Mini PCI Express 2xHS FW 4.18.778 it was observed
that if the device was bus-off when stopped, at next start (either via
interface down/up or manual bus-off restart) the initial
CMD_CHIP_STATE_EVENT received just after CMD_START_CHIP_REPLY will have
the M16C_STATE_BUS_OFF bit still set, causing the interface to
immediately go bus-off again.

The bit seems to internally clear quickly afterwards but we do not get
another CMD_CHIP_STATE_EVENT.

Fix the issue by ignoring any initial bus-off state until we see at
least one bus-on state. Also, poll the state periodically until that
occurs.

It is possible we lose one actual immediately occurring bus-off event
here in which case the HW will auto-recover and we see the recovery
event. We will then catch the next bus-off event, if any.

This issue did not reproduce with 0bfd:0017 Kvaser Memorator
Professional HS/HS FW 2.0.50.

Fixes: 71873a9b ("can: kvaser_usb: Add support for more Kvaser Leaf v2 devices")
Tested-by: default avatarJimmy Assarsson <extja@kvaser.com>
Signed-off-by: default avatarAnssi Hannula <anssi.hannula@bitwise.fi>
Signed-off-by: default avatarJimmy Assarsson <extja@kvaser.com>
Link: https://lore.kernel.org/all/20221010185237.319219-9-extja@kvaser.com


Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent a11249ac

drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c

+30 −1
Original line number Diff line number Diff line
@@ -427,6 +427,9 @@ struct kvaser_usb_net_leaf_priv { 
	struct kvaser_usb_net_priv *net;



	struct delayed_work chip_state_req_work;



	/* started but not reported as bus-on yet */

	bool joining_bus;

};



static const struct can_bittiming_const kvaser_usb_leaf_m16c_bittiming_const = {
@@ -966,6 +969,7 @@ kvaser_usb_leaf_rx_error_update_can_state(struct kvaser_usb_net_priv *priv, 
					const struct kvaser_usb_err_summary *es,

					struct can_frame *cf)

{

	struct kvaser_usb_net_leaf_priv *leaf = priv->sub_priv;

	struct kvaser_usb *dev = priv->dev;

	struct net_device_stats *stats = &priv->netdev->stats;

	enum can_state cur_state, new_state, tx_state, rx_state;
@@ -990,6 +994,22 @@ kvaser_usb_leaf_rx_error_update_can_state(struct kvaser_usb_net_priv *priv, 
		new_state = CAN_STATE_ERROR_ACTIVE;

	}



	/* 0bfd:0124 FW 4.18.778 was observed to send the initial

	 * CMD_CHIP_STATE_EVENT after CMD_START_CHIP with M16C_STATE_BUS_OFF

	 * bit set if the channel was bus-off when it was last stopped (even

	 * across chip resets). This bit will clear shortly afterwards, without

	 * triggering a second unsolicited chip state event.

	 * Ignore this initial bus-off.

	 */

	if (leaf->joining_bus) {

		if (new_state == CAN_STATE_BUS_OFF) {

			netdev_dbg(priv->netdev, "ignoring bus-off during startup");

			new_state = cur_state;

		} else {

			leaf->joining_bus = false;

		}

	}



	if (new_state != cur_state) {

		tx_state = (es->txerr >= es->rxerr) ? new_state : 0;

		rx_state = (es->txerr <= es->rxerr) ? new_state : 0;
@@ -1065,9 +1085,12 @@ static void kvaser_usb_leaf_rx_error(const struct kvaser_usb *dev, 


	/* If there are errors, request status updates periodically as we do

	 * not get automatic notifications of improved state.

	 * Also request updates if we saw a stale BUS_OFF during startup

	 * (joining_bus).

	 */

	if (new_state < CAN_STATE_BUS_OFF &&

	    (es->rxerr || es->txerr || new_state == CAN_STATE_ERROR_PASSIVE))

	    (es->rxerr || es->txerr || new_state == CAN_STATE_ERROR_PASSIVE ||

	     leaf->joining_bus))

		schedule_delayed_work(&leaf->chip_state_req_work,

				      msecs_to_jiffies(500));
@@ -1587,8 +1610,11 @@ static int kvaser_usb_leaf_set_opt_mode(const struct kvaser_usb_net_priv *priv) 


static int kvaser_usb_leaf_start_chip(struct kvaser_usb_net_priv *priv)

{

	struct kvaser_usb_net_leaf_priv *leaf = priv->sub_priv;

	int err;



	leaf->joining_bus = true;



	init_completion(&priv->start_comp);



	err = kvaser_usb_leaf_send_simple_cmd(priv->dev, CMD_START_CHIP,
@@ -1719,12 +1745,15 @@ static int kvaser_usb_leaf_set_mode(struct net_device *netdev, 
				    enum can_mode mode)

{

	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);

	struct kvaser_usb_net_leaf_priv *leaf = priv->sub_priv;

	int err;



	switch (mode) {

	case CAN_MODE_START:

		kvaser_usb_unlink_tx_urbs(priv);



		leaf->joining_bus = true;



		err = kvaser_usb_leaf_simple_cmd_async(priv, CMD_START_CHIP);

		if (err)

			return err;