can: c_can: Handle state change correctly

If the allocation of an error skb fails, the state change handling
returns w/o doing any work. That leaves the interface in a wreckaged
state as the internal status is wrong.

Split the interface handling and the skb handling.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 20 insertions, 5 deletions

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 603876109ba8..246bcf92558c 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -914,6 +914,26 @@ static int c_can_handle_state_change(struct net_device *dev,
         struct sk_buff *skb;
         struct can_berr_counter bec;
 
+        switch (error_type) {
+        case C_CAN_ERROR_WARNING:
+                /* error warning state */
+                priv->can.can_stats.error_warning++;
+                priv->can.state = CAN_STATE_ERROR_WARNING;
+                break;
+        case C_CAN_ERROR_PASSIVE:
+                /* error passive state */
+                priv->can.can_stats.error_passive++;
+                priv->can.state = CAN_STATE_ERROR_PASSIVE;
+                break;
+        case C_CAN_BUS_OFF:
+                /* bus-off state */
+                priv->can.state = CAN_STATE_BUS_OFF;
+                can_bus_off(dev);
+                break;
+        default:
+                break;
+        }
+
         /* propagate the error condition to the CAN stack */
         skb = alloc_can_err_skb(dev, &cf);
         if (unlikely(!skb))
@@ -927,8 +947,6 @@ static int c_can_handle_state_change(struct net_device *dev,
         switch (error_type) {
         case C_CAN_ERROR_WARNING:
                 /* error warning state */
-                priv->can.can_stats.error_warning++;
-                priv->can.state = CAN_STATE_ERROR_WARNING;
                 cf->can_id |= CAN_ERR_CRTL;
                 cf->data[1] = (bec.txerr > bec.rxerr) ?
                         CAN_ERR_CRTL_TX_WARNING :
@@ -939,8 +957,6 @@ static int c_can_handle_state_change(struct net_device *dev,
                 break;
         case C_CAN_ERROR_PASSIVE:
                 /* error passive state */
-                priv->can.can_stats.error_passive++;
-                priv->can.state = CAN_STATE_ERROR_PASSIVE;
                 cf->can_id |= CAN_ERR_CRTL;
                 if (rx_err_passive)
                         cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
@@ -952,7 +968,6 @@ static int c_can_handle_state_change(struct net_device *dev,
                 break;
         case C_CAN_BUS_OFF:
                 /* bus-off state */
-                priv->can.state = CAN_STATE_BUS_OFF;
                 cf->can_id |= CAN_ERR_BUSOFF;
                 can_bus_off(dev);
                 break;