[PATCH v5 3/5] can: kvaser_usb: Fix state handling upon BUS_ERROR events
From: Ahmed S. Darwish <hidden>
Date: 2015-01-20 21:47:16
Also in:
lkml, netdev
Subsystem:
can network drivers, the rest · Maintainers:
Marc Kleine-Budde, Vincent Mailhol, Linus Torvalds
From: Ahmed S. Darwish <redacted> While being in an ERROR_WARNING state and receiving further bus error events with error counts in the range of 97-127 inclusive, the state handling code erroneously reverts back to ERROR_ACTIVE. As per the CAN standard recommendations, 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 ops instead of full equality for checking the register against bus errors. Signed-off-by: Ahmed S. Darwish <redacted> --- drivers/net/can/usb/kvaser_usb.c | 24 +++++++++++------------- 1 file changed, 11 insertions(+), 13 deletions(-)
diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
index 0386d3f..640b0eb 100644
--- a/drivers/net/can/usb/kvaser_usb.c
+++ b/drivers/net/can/usb/kvaser_usb.c@@ -635,10 +635,12 @@ static void kvaser_usb_rx_error_update_can_state(struct kvaser_usb_net_priv *pri new_state = CAN_STATE_BUS_OFF; else if (es->status & M16C_STATE_BUS_PASSIVE) new_state = CAN_STATE_ERROR_PASSIVE; - - if (es->status == M16C_STATE_BUS_ERROR) { - if ((cur_state < CAN_STATE_ERROR_WARNING) && - ((es->txerr >= 96) || (es->rxerr >= 96))) + else if (es->status & M16C_STATE_BUS_ERROR) { + if ((es->txerr >= 256) || (es->rxerr >= 256)) + new_state = CAN_STATE_BUS_OFF; + else if ((es->txerr >= 128) || (es->rxerr >= 128)) + new_state = CAN_STATE_ERROR_PASSIVE; + else if ((es->txerr >= 96) || (es->rxerr >= 96)) new_state = CAN_STATE_ERROR_WARNING; else if (cur_state > CAN_STATE_ERROR_ACTIVE) new_state = CAN_STATE_ERROR_ACTIVE;
@@ -748,15 +750,11 @@ static void kvaser_usb_rx_error(const struct kvaser_usb *dev, if (!priv->can.restart_ms) kvaser_usb_simple_msg_async(priv, CMD_STOP_CHIP); netif_carrier_off(priv->netdev); - } - - if (es.status == M16C_STATE_BUS_ERROR) { - if ((old_state >= CAN_STATE_ERROR_WARNING) || - (es.txerr < 96 && es.rxerr < 96)) { - if (old_state > CAN_STATE_ERROR_ACTIVE) { - cf->can_id |= CAN_ERR_PROT; - cf->data[2] = CAN_ERR_PROT_ACTIVE; - } + } else if (es.status & M16C_STATE_BUS_ERROR) { + if ((es.txerr < 96 && es.rxerr < 96) && + (old_state > CAN_STATE_ERROR_ACTIVE)) { + cf->can_id |= CAN_ERR_PROT; + cf->data[2] = CAN_ERR_PROT_ACTIVE; } }
--
1.9.1