Commit b32ff466 authored by Dario Binacchi's avatar Dario Binacchi Committed by Marc Kleine-Budde
Browse files

can: slcan: extend the protocol with error info 

It extends the protocol to receive the adapter CAN communication errors
and forward them to the netdev upper levels.

Link: https://lore.kernel.org/all/20220628163137.413025-12-dario.binacchi@amarulasolutions.com


Signed-off-by: default avatarDario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 4de0e8ef

drivers/net/can/slcan/slcan-core.c

+139 −1
Original line number Diff line number Diff line
@@ -175,7 +175,7 @@ int slcan_enable_err_rst_on_open(struct net_device *ndev, bool on) 
  ************************************************************************/



/* Send one completely decapsulated can_frame to the network layer */

static void slc_bump(struct slcan *sl)

static void slc_bump_frame(struct slcan *sl)

{

	struct sk_buff *skb;

	struct can_frame *cf;
@@ -254,6 +254,144 @@ static void slc_bump(struct slcan *sl) 
	dev_kfree_skb(skb);

}



/* An error frame can contain more than one type of error.

 *

 * Examples:

 *

 * e1a : len 1, errors: ACK error

 * e3bcO: len 3, errors: Bit0 error, CRC error, Tx overrun error

 */

static void slc_bump_err(struct slcan *sl)

{

	struct net_device *dev = sl->dev;

	struct sk_buff *skb;

	struct can_frame *cf;

	char *cmd = sl->rbuff;

	bool rx_errors = false, tx_errors = false, rx_over_errors = false;

	int i, len;



	/* get len from sanitized ASCII value */

	len = cmd[1];

	if (len >= '0' && len < '9')

		len -= '0';

	else

		return;



	if ((len + SLC_CMD_LEN + 1) > sl->rcount)

		return;



	skb = alloc_can_err_skb(dev, &cf);



	if (skb)

		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;



	cmd += SLC_CMD_LEN + 1;

	for (i = 0; i < len; i++, cmd++) {

		switch (*cmd) {

		case 'a':

			netdev_dbg(dev, "ACK error\n");

			tx_errors = true;

			if (skb) {

				cf->can_id |= CAN_ERR_ACK;

				cf->data[3] = CAN_ERR_PROT_LOC_ACK;

			}



			break;

		case 'b':

			netdev_dbg(dev, "Bit0 error\n");

			tx_errors = true;

			if (skb)

				cf->data[2] |= CAN_ERR_PROT_BIT0;



			break;

		case 'B':

			netdev_dbg(dev, "Bit1 error\n");

			tx_errors = true;

			if (skb)

				cf->data[2] |= CAN_ERR_PROT_BIT1;



			break;

		case 'c':

			netdev_dbg(dev, "CRC error\n");

			rx_errors = true;

			if (skb) {

				cf->data[2] |= CAN_ERR_PROT_BIT;

				cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;

			}



			break;

		case 'f':

			netdev_dbg(dev, "Form Error\n");

			rx_errors = true;

			if (skb)

				cf->data[2] |= CAN_ERR_PROT_FORM;



			break;

		case 'o':

			netdev_dbg(dev, "Rx overrun error\n");

			rx_over_errors = true;

			rx_errors = true;

			if (skb) {

				cf->can_id |= CAN_ERR_CRTL;

				cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;

			}



			break;

		case 'O':

			netdev_dbg(dev, "Tx overrun error\n");

			tx_errors = true;

			if (skb) {

				cf->can_id |= CAN_ERR_CRTL;

				cf->data[1] = CAN_ERR_CRTL_TX_OVERFLOW;

			}



			break;

		case 's':

			netdev_dbg(dev, "Stuff error\n");

			rx_errors = true;

			if (skb)

				cf->data[2] |= CAN_ERR_PROT_STUFF;



			break;

		default:

			if (skb)

				dev_kfree_skb(skb);



			return;

		}

	}



	if (rx_errors)

		dev->stats.rx_errors++;



	if (rx_over_errors)

		dev->stats.rx_over_errors++;



	if (tx_errors)

		dev->stats.tx_errors++;



	if (skb)

		netif_rx(skb);

}



static void slc_bump(struct slcan *sl)

{

	switch (sl->rbuff[0]) {

	case 'r':

		fallthrough;

	case 't':

		fallthrough;

	case 'R':

		fallthrough;

	case 'T':

		return slc_bump_frame(sl);

	case 'e':

		return slc_bump_err(sl);

	default:

		return;

	}

}



/* parse tty input stream */

static void slcan_unesc(struct slcan *sl, unsigned char s)

{