Commit e638642b authored Jan 26, 2015 by Ahmed S. Darwish Committed by Marc Kleine-Budde Jan 27, 2015

can: kvaser_usb: Fix state handling upon BUS_ERROR events



While being in an ERROR_WARNING state, and receiving further
bus error events with error counters still in the ERROR_WARNING
range of 97-127 inclusive, the state handling code erroneously
reverts back to ERROR_ACTIVE.

Per the CAN standard, only revert to ERROR_ACTIVE when the
error counters are less than 96.

Moreover, in certain Kvaser models, the BUS_ERROR flag is
always set along with undefined bits in the M16C status
register. Thus use bitwise operators instead of full equality
for checking that register against bus errors.

Signed-off-by: Ahmed S. Darwish <ahmed.darwish@valeo.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

parent 14c10c2a

drivers/net/can/usb/kvaser_usb.c

+3 −4

Original line number	Diff line number	Diff line
		@@ -698,9 +698,7 @@ static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
		}

		new_state = CAN_STATE_ERROR_PASSIVE;
		}

		if (status == M16C_STATE_BUS_ERROR) {
		} else if (status & M16C_STATE_BUS_ERROR) {
		if ((priv->can.state < CAN_STATE_ERROR_WARNING) &&
		((txerr >= 96) \|\| (rxerr >= 96))) {
		cf->can_id \|= CAN_ERR_CRTL;
		@@ -710,7 +708,8 @@ static void kvaser_usb_rx_error(const struct kvaser_usb *dev,

		priv->can.can_stats.error_warning++;
		new_state = CAN_STATE_ERROR_WARNING;
		} else if (priv->can.state > CAN_STATE_ERROR_ACTIVE) {
		} else if ((priv->can.state > CAN_STATE_ERROR_ACTIVE) &&
		((txerr < 96) && (rxerr < 96))) {
		cf->can_id \|= CAN_ERR_PROT;
		cf->data[2] = CAN_ERR_PROT_ACTIVE;