1 files changed, 49 insertions, 33 deletions

diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c
index 0ada0e160e93..a8fa0d6516b9 100644
--- a/drivers/net/can/sja1000/sja1000.c
+++ b/drivers/net/can/sja1000/sja1000.c
@@ -206,7 +206,7 @@ static void sja1000_start(struct net_device *dev)
 {
 	struct sja1000_priv *priv = netdev_priv(dev);
 
-	/* leave reset mode */
+	/* enter reset mode */
 	if (priv->can.state != CAN_STATE_STOPPED)
 		set_reset_mode(dev);
 
@@ -392,7 +392,13 @@ static irqreturn_t sja1000_reset_interrupt(int irq, void *dev_id)
 	struct net_device *dev = (struct net_device *)dev_id;
 
 	netdev_dbg(dev, "performing a soft reset upon overrun\n");
-	sja1000_start(dev);
+
+	netif_tx_lock(dev);
+
+	can_free_echo_skb(dev, 0, NULL);
+	sja1000_set_mode(dev, CAN_MODE_START);
+
+	netif_tx_unlock(dev);
 
 	return IRQ_HANDLED;
 }
@@ -410,8 +416,6 @@ static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
 	int ret = 0;
 
 	skb = alloc_can_err_skb(dev, &cf);
-	if (skb == NULL)
-		return -ENOMEM;
 
 	txerr = priv->read_reg(priv, SJA1000_TXERR);
 	rxerr = priv->read_reg(priv, SJA1000_RXERR);
@@ -419,8 +423,11 @@ static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
 	if (isrc & IRQ_DOI) {
 		/* data overrun interrupt */
 		netdev_dbg(dev, "data overrun interrupt\n");
-		cf->can_id |= CAN_ERR_CRTL;
-		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
+		if (skb) {
+			cf->can_id |= CAN_ERR_CRTL;
+			cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
+		}
+
 		stats->rx_over_errors++;
 		stats->rx_errors++;
 		sja1000_write_cmdreg(priv, CMD_CDO);	/* clear bit */
@@ -446,7 +453,7 @@ static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
 		else
 			state = CAN_STATE_ERROR_ACTIVE;
 	}
-	if (state != CAN_STATE_BUS_OFF) {
+	if (state != CAN_STATE_BUS_OFF && skb) {
 		cf->can_id |= CAN_ERR_CNT;
 		cf->data[6] = txerr;
 		cf->data[7] = rxerr;
@@ -454,33 +461,38 @@ static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
 	if (isrc & IRQ_BEI) {
 		/* bus error interrupt */
 		priv->can.can_stats.bus_error++;
-		stats->rx_errors++;
 
 		ecc = priv->read_reg(priv, SJA1000_ECC);
+		if (skb) {
+			cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 
-		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
-
-		/* set error type */
-		switch (ecc & ECC_MASK) {
-		case ECC_BIT:
-			cf->data[2] |= CAN_ERR_PROT_BIT;
-			break;
-		case ECC_FORM:
-			cf->data[2] |= CAN_ERR_PROT_FORM;
-			break;
-		case ECC_STUFF:
-			cf->data[2] |= CAN_ERR_PROT_STUFF;
-			break;
-		default:
-			break;
-		}
+			/* set error type */
+			switch (ecc & ECC_MASK) {
+			case ECC_BIT:
+				cf->data[2] |= CAN_ERR_PROT_BIT;
+				break;
+			case ECC_FORM:
+				cf->data[2] |= CAN_ERR_PROT_FORM;
+				break;
+			case ECC_STUFF:
+				cf->data[2] |= CAN_ERR_PROT_STUFF;
+				break;
+			default:
+				break;
+			}
 
-		/* set error location */
-		cf->data[3] = ecc & ECC_SEG;
+			/* set error location */
+			cf->data[3] = ecc & ECC_SEG;
+		}
 
 		/* Error occurred during transmission? */
-		if ((ecc & ECC_DIR) == 0)
-			cf->data[2] |= CAN_ERR_PROT_TX;
+		if ((ecc & ECC_DIR) == 0) {
+			stats->tx_errors++;
+			if (skb)
+				cf->data[2] |= CAN_ERR_PROT_TX;
+		} else {
+			stats->rx_errors++;
+		}
 	}
 	if (isrc & IRQ_EPI) {
 		/* error passive interrupt */
@@ -496,8 +508,10 @@ static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
 		netdev_dbg(dev, "arbitration lost interrupt\n");
 		alc = priv->read_reg(priv, SJA1000_ALC);
 		priv->can.can_stats.arbitration_lost++;
-		cf->can_id |= CAN_ERR_LOSTARB;
-		cf->data[0] = alc & 0x1f;
+		if (skb) {
+			cf->can_id |= CAN_ERR_LOSTARB;
+			cf->data[0] = alc & 0x1f;
+		}
 	}
 
 	if (state != priv->can.state) {
@@ -510,6 +524,9 @@ static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
 			can_bus_off(dev);
 	}
 
+	if (!skb)
+		return -ENOMEM;
+
 	netif_rx(skb);
 
 	return ret;
@@ -531,8 +548,8 @@ irqreturn_t sja1000_interrupt(int irq, void *dev_id)
 	if (priv->read_reg(priv, SJA1000_IER) == IRQ_OFF)
 		goto out;
 
-	while ((isrc = priv->read_reg(priv, SJA1000_IR)) &&
-	       (n < SJA1000_MAX_IRQ)) {
+	while ((n < SJA1000_MAX_IRQ) &&
+	       (isrc = priv->read_reg(priv, SJA1000_IR))) {
 
 		status = priv->read_reg(priv, SJA1000_SR);
 		/* check for absent controller due to hw unplug */
@@ -680,7 +697,6 @@ static const struct net_device_ops sja1000_netdev_ops = {
 	.ndo_open	= sja1000_open,
 	.ndo_stop	= sja1000_close,
 	.ndo_start_xmit	= sja1000_start_xmit,
-	.ndo_change_mtu	= can_change_mtu,
 };
 
 static const struct ethtool_ops sja1000_ethtool_ops = {