can: flexcan: handle state passive -> warning transition

Once the CAN-bus is open and a packet is sent, the controller switches
into the PASSIVE state. Once the BUS is closed again it goes the back
err-warning. The TX error counter goes 0 -> 0x80 -> 0x7f.
This patch makes sure that the user learns about this state chang
(CAN_STATE_ERROR_WARNING => CAN_STATE_ERROR_PASSIVE)

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Matthias Klein <matthias.klein@optimeas.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index a691651f9ad9..944aa5d3af6e 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -549,6 +549,13 @@ static void do_state(struct net_device *dev,
 
         /* process state changes depending on the new state */
         switch (new_state) {
+        case CAN_STATE_ERROR_WARNING:
+                netdev_dbg(dev, "Error Warning\n");
+                cf->can_id |= CAN_ERR_CRTL;
+                cf->data[1] = (bec.txerr > bec.rxerr) ?
+                        CAN_ERR_CRTL_TX_WARNING :
+                        CAN_ERR_CRTL_RX_WARNING;
+                break;
         case CAN_STATE_ERROR_ACTIVE:
                 netdev_dbg(dev, "Error Active\n");
                 cf->can_id |= CAN_ERR_PROT;