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can: kvaser_usb_leaf: Ignore stale bus-off after start

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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: 71873a9b38 ("can: kvaser_usb: Add support for more Kvaser Leaf v2 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/20221010185237.319219-9-extja@kvaser.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Anssi Hannula 2022-10-10 20:52:34 +02:00 committed by Marc Kleine-Budde
parent a11249acf8
commit abb8670938
1 changed files with 30 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
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@ -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;