Consolidate and unify state change handling

index 2700865..96a0755 100644
@@ -559,74 +559,15 @@ static int flexcan_poll_bus_err(struct net_device *dev, u32 reg_esr)
 static void do_state(struct net_device *dev,
              struct can_frame *cf, enum can_state new_state)
 {
-    struct flexcan_priv *priv = netdev_priv(dev);
     struct can_berr_counter bec;
 
     __flexcan_get_berr_counter(dev, &bec);
 
-    switch (priv->can.state) {
-    case CAN_STATE_ERROR_ACTIVE:
-        /*
-         * from: ERROR_ACTIVE
-         * to  : ERROR_WARNING, ERROR_PASSIVE, BUS_OFF
-         * =>  : there was a warning int
-         */
-        if (new_state >= CAN_STATE_ERROR_WARNING &&
-            new_state <= CAN_STATE_BUS_OFF) {
-            netdev_dbg(dev, "Error Warning IRQ\n");
-            priv->can.can_stats.error_warning++;
-
-            cf->can_id |= CAN_ERR_CRTL;
-            cf->data[1] = (bec.txerr > bec.rxerr) ?
-                CAN_ERR_CRTL_TX_WARNING :
-                CAN_ERR_CRTL_RX_WARNING;
-        }
-    case CAN_STATE_ERROR_WARNING:    /* fallthrough */
-        /*
-         * from: ERROR_ACTIVE, ERROR_WARNING
-         * to  : ERROR_PASSIVE, BUS_OFF
-         * =>  : error passive int
-         */
-        if (new_state >= CAN_STATE_ERROR_PASSIVE &&
-            new_state <= CAN_STATE_BUS_OFF) {
-            netdev_dbg(dev, "Error Passive IRQ\n");
-            priv->can.can_stats.error_passive++;
-
-            cf->can_id |= CAN_ERR_CRTL;
-            cf->data[1] = (bec.txerr > bec.rxerr) ?
-                CAN_ERR_CRTL_TX_PASSIVE :
-                CAN_ERR_CRTL_RX_PASSIVE;
-        }
-        break;
-    case CAN_STATE_BUS_OFF:
-        netdev_err(dev, "BUG! "
-               "hardware recovered automatically from BUS_OFF\n");
-        break;
-    default:
-        break;
-    }
+    can_change_state(dev, cf, new_state,
+             can_get_err_dir(bec.rxerr, bec.txerr));
 
-    /* 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;
-        cf->data[2] = CAN_ERR_PROT_ACTIVE;
-        break;
-    case CAN_STATE_BUS_OFF:
-        cf->can_id |= CAN_ERR_BUSOFF;
+    if (unlikely(new_state == CAN_STATE_BUS_OFF))
         can_bus_off(dev);
-        break;
-    default:
-        break;
-    }
 }
 
 static int flexcan_poll_state(struct net_device *dev, u32 reg_esr)

@@ -658,7 +599,6 @@ static int flexcan_poll_state(struct net_device *dev, u32 reg_esr)
         return 0;
 
     do_state(dev, cf, new_state);
-    priv->can.state = new_state;
     netif_receive_skb(skb);
 
     dev->stats.rx_packets++;