The patch below does not apply to the 5.15-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 <stable@xxxxxxxxxxxxxxx>. Possible dependencies: 918ee4911f7a ("can: esd_usb: Allow REC and TEC to return to zero") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 918ee4911f7a41fb4505dff877c1d7f9f64eb43e Mon Sep 17 00:00:00 2001 From: Frank Jungclaus <frank.jungclaus@xxxxxx> Date: Wed, 30 Nov 2022 21:22:42 +0100 Subject: [PATCH] can: esd_usb: Allow REC and TEC to return to zero We don't get any further EVENT from an esd CAN USB device for changes on REC or TEC while those counters converge to 0 (with ecc == 0). So when handling the "Back to Error Active"-event force txerr = rxerr = 0, otherwise the berr-counters might stay on values like 95 forever. Also, to make life easier during the ongoing development a netdev_dbg() has been introduced to allow dumping error events send by an esd CAN USB device. Fixes: 96d8e90382dc ("can: Add driver for esd CAN-USB/2 device") Signed-off-by: Frank Jungclaus <frank.jungclaus@xxxxxx> Link: https://lore.kernel.org/all/20221130202242.3998219-2-frank.jungclaus@xxxxxx Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> diff --git a/drivers/net/can/usb/esd_usb.c b/drivers/net/can/usb/esd_usb.c index 81b88e9e5bdc..42323f5e6f3a 100644 --- a/drivers/net/can/usb/esd_usb.c +++ b/drivers/net/can/usb/esd_usb.c @@ -234,6 +234,10 @@ static void esd_usb_rx_event(struct esd_usb_net_priv *priv, u8 rxerr = msg->msg.rx.data[2]; u8 txerr = msg->msg.rx.data[3]; + netdev_dbg(priv->netdev, + "CAN_ERR_EV_EXT: dlc=%#02x state=%02x ecc=%02x rec=%02x tec=%02x\n", + msg->msg.rx.dlc, state, ecc, rxerr, txerr); + skb = alloc_can_err_skb(priv->netdev, &cf); if (skb == NULL) { stats->rx_dropped++; @@ -260,6 +264,8 @@ static void esd_usb_rx_event(struct esd_usb_net_priv *priv, break; default: priv->can.state = CAN_STATE_ERROR_ACTIVE; + txerr = 0; + rxerr = 0; break; } } else {