From: Anssi Hannula <anssi.hannula@xxxxxxxxxx>
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.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 71873a9b38d1 ("can: kvaser_usb: Add support for more Kvaser Leaf v2 devices")
Tested-by: Jimmy Assarsson <extja@xxxxxxxxxx>
Signed-off-by: Anssi Hannula <anssi.hannula@xxxxxxxxxx>
Signed-off-by: Jimmy Assarsson <extja@xxxxxxxxxx>
---
Changes in v4:
- No changes
Changes in v3:
- Rebased on 1d5eeda23f36 ("can: kvaser_usb: advertise timestamping capabilities and add ioctl support")
- Add stable to CC
- Add S-o-b
Changes in v2:
- Rebased on b3b6df2c56d8 ("can: kvaser_usb: kvaser_usb_leaf: fix bittiming limits")
.../net/can/usb/kvaser_usb/kvaser_usb_leaf.c | 31 ++++++++++++++++++-
1 file changed, 30 insertions(+), 1 deletion(-)
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 4f9c76f4d0da..f8a12a285050 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
@@ -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;
+
reinit_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;
--
2.37.3
