Linux Kernels

can: c_can: C_CAN: add bus recovery events

This change “can: c_can: C_CAN: add bus recovery events” (commit 6f12001) in Linux kernel is authored by Jeroen Hofstee <jhofstee [at] victronenergy.com> on Tue Oct 1 21:01:24 2019 +0000.

Description of "can: c_can: C_CAN: add bus recovery events"

The change “can: c_can: C_CAN: add bus recovery events” introduces changes as follows.

can: c_can: C_CAN: add bus recovery events

While the state is updated 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@victronenergy.com>
Acked-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
Tested-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Linux kernel releases containing commit 6f12001

The Linux kernel releases containing this commit are as follows.

Linux kernel code changes in "can: c_can: C_CAN: add bus recovery events"

There are 20 lines of Linux source code added/deleted in this change. Code changes to Linux kernel are as follows.

 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 24c6015f6c92..8e9f5620c9a2 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -915,6 +915,9 @@ 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++;
@@ -945,6 +948,13 @@ 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;
@@ -1089,11 +1099,17 @@ 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 */

The commit for this change in Linux stable tree is 6f12001 (patch).

Last modified: 2020/01/11 09:48