can: kvaser_pciefd: Update stats and state even if alloc_can_err_skb() fails

Ensure statistics, error counters, and CAN state are updated consistently,
even when alloc_can_err_skb() fails during state changes or error message
frame reception.

Signed-off-by: Jimmy Assarsson <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>

Author: Jimmy Assarsson

drivers/net/can/kvaser_pciefd.c

@@ -1234,11 +1234,15 @@ static int kvaser_pciefd_handle_data_packet(struct kvaser_pciefd *pcie,
 }
 
 static void kvaser_pciefd_change_state(struct kvaser_pciefd_can *can,
+				       const struct can_berr_counter *bec,
 				       struct can_frame *cf,
 				       enum can_state new_state,
 				       enum can_state tx_state,
 				       enum can_state rx_state)
 {
+	enum can_state old_state;
+
+	old_state = can->can.state;
 	can_change_state(can->can.dev, cf, tx_state, rx_state);
 
 	if (new_state == CAN_STATE_BUS_OFF) {
@@ -1254,6 +1258,18 @@ static void kvaser_pciefd_change_state(struct kvaser_pciefd_can *can,
 			can_bus_off(ndev);
 		}
 	}
+	if (old_state == CAN_STATE_BUS_OFF &&
+	    new_state == CAN_STATE_ERROR_ACTIVE &&
+	    can->can.restart_ms) {
+		can->can.can_stats.restarts++;
+		if (cf)
+			cf->can_id |= CAN_ERR_RESTARTED;
+	}
+	if (cf && new_state != CAN_STATE_BUS_OFF) {
+		cf->can_id |= CAN_ERR_CNT;
+		cf->data[6] = bec->txerr;
+		cf->data[7] = bec->rxerr;
+	}
 }
 
 static void kvaser_pciefd_packet_to_state(struct kvaser_pciefd_rx_packet *p,
@@ -1299,14 +1315,7 @@ static int kvaser_pciefd_rx_error_frame(struct kvaser_pciefd_can *can,
 	kvaser_pciefd_packet_to_state(p, &bec, &new_state, &tx_state, &rx_state);
 	skb = alloc_can_err_skb(ndev, &cf);
 	if (new_state != old_state) {
-		kvaser_pciefd_change_state(can, cf, new_state, tx_state, rx_state);
-		if (old_state == CAN_STATE_BUS_OFF &&
-		    new_state == CAN_STATE_ERROR_ACTIVE &&
-		    can->can.restart_ms) {
-			can->can.can_stats.restarts++;
-			if (skb)
-				cf->can_id |= CAN_ERR_RESTARTED;
-		}
+		kvaser_pciefd_change_state(can, &bec, cf, new_state, tx_state, rx_state);
 	}
 
 	can->err_rep_cnt++;
@@ -1359,6 +1368,7 @@ static int kvaser_pciefd_handle_status_resp(struct kvaser_pciefd_can *can,
 {
 	struct can_berr_counter bec;
 	enum can_state old_state, new_state, tx_state, rx_state;
+	int ret = 0;
 
 	old_state = can->can.state;
 
@@ -1372,33 +1382,23 @@ static int kvaser_pciefd_handle_status_resp(struct kvaser_pciefd_can *can,
 		struct can_frame *cf;
 
 		skb = alloc_can_err_skb(ndev, &cf);
-		if (!skb) {
+		kvaser_pciefd_change_state(can, &bec, cf, new_state, tx_state, rx_state);
+		if (skb) {
+			kvaser_pciefd_set_skb_timestamp(can->kv_pcie, skb, p->timestamp);
+			netif_rx(skb);
+		} else {
 			ndev->stats.rx_dropped++;
-			return -ENOMEM;
+			netdev_warn(ndev, "No memory left for err_skb\n");
+			ret = -ENOMEM;
 		}
-
-		kvaser_pciefd_change_state(can, cf, new_state, tx_state, rx_state);
-		if (old_state == CAN_STATE_BUS_OFF &&
-		    new_state == CAN_STATE_ERROR_ACTIVE &&
-		    can->can.restart_ms) {
-			can->can.can_stats.restarts++;
-			cf->can_id |= CAN_ERR_RESTARTED;
-		}
-
-		kvaser_pciefd_set_skb_timestamp(can->kv_pcie, skb, p->timestamp);
-
-		cf->data[6] = bec.txerr;
-		cf->data[7] = bec.rxerr;
-
-		netif_rx(skb);
 	}
 	can->bec.txerr = bec.txerr;
 	can->bec.rxerr = bec.rxerr;
 	/* Check if we need to poll the error counters */
 	if (bec.txerr || bec.rxerr)
 		mod_timer(&can->bec_poll_timer, KVASER_PCIEFD_BEC_POLL_FREQ);
 
-	return 0;
+	return ret;
 }
 
 static int kvaser_pciefd_handle_status_packet(struct kvaser_pciefd *pcie,