[PATCH 2/2] can: C_CAN: add bus recovery events

[Jeroen Hofstee]

While the state is update when the error counters increase and decrease,
there is no event when the bus recovers and the error counters decrease
again. So add that event as well.

Change the state going downward to be ERROR_PASSIVE -> ERROR_WARNING ->
ERROR_ACTIVE instead of directly to ERROR_ACTIVE again.

Signed-off-by: Jeroen Hofstee <jhofstee@xxxxxxxxxxxxxxxxx>
---
 drivers/net/can/c_can/c_can.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 502a181d02e7..5cfaab18e10b 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -912,6 +912,9 @@ static int c_can_handle_state_change(struct net_device *dev,
 	struct can_berr_counter bec;
 
 	switch (error_type) {
+	case C_CAN_NO_ERROR:
+		priv->can.state = CAN_STATE_ERROR_ACTIVE;
+		break;
 	case C_CAN_ERROR_WARNING:
 		/* error warning state */
 		priv->can.can_stats.error_warning++;
@@ -942,6 +945,13 @@ static int c_can_handle_state_change(struct net_device *dev,
 				ERR_CNT_RP_SHIFT;
 
 	switch (error_type) {
+	case C_CAN_NO_ERROR:
+		/* error warning state */
+		cf->can_id |= CAN_ERR_CRTL;
+		cf->data[1] = CAN_ERR_CRTL_ACTIVE;
+		cf->data[6] = bec.txerr;
+		cf->data[7] = bec.rxerr;
+		break;
 	case C_CAN_ERROR_WARNING:
 		/* error warning state */
 		cf->can_id |= CAN_ERR_CRTL;
@@ -1080,11 +1090,17 @@ static int c_can_poll(struct napi_struct *napi, int quota)
 	/* handle bus recovery events */
 	if ((!(curr & STATUS_BOFF)) && (last & STATUS_BOFF)) {
 		netdev_dbg(dev, "left bus off state\n");
-		priv->can.state = CAN_STATE_ERROR_ACTIVE;
+		work_done += c_can_handle_state_change(dev, C_CAN_ERROR_PASSIVE);
 	}
+
 	if ((!(curr & STATUS_EPASS)) && (last & STATUS_EPASS)) {
 		netdev_dbg(dev, "left error passive state\n");
-		priv->can.state = CAN_STATE_ERROR_ACTIVE;
+		work_done += c_can_handle_state_change(dev, C_CAN_ERROR_WARNING);
+	}
+
+	if ((!(curr & STATUS_EWARN)) && (last & STATUS_EWARN)) {
+		netdev_dbg(dev, "left error warning state\n");
+		work_done += c_can_handle_state_change(dev, C_CAN_NO_ERROR);
 	}
 
 	/* handle lec errors on the bus */
-- 
2.17.1