Merge branch 'sh_eth'

Ben Hutchings says:

====================
Fixes for sh_eth #2

I'm continuing review and testing of Ethernet support on the R-Car H2
chip.  This series fixes more of the issues I've found, but it won't be
the last set.

These are not tested on any of the other supported chips.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/renesas/sh_eth.c

@@ -1316,8 +1316,10 @@ static int sh_eth_dev_init(struct net_device *ndev, bool start)
 		     RFLR);
 
 	sh_eth_write(ndev, sh_eth_read(ndev, EESR), EESR);
-	if (start)
+	if (start) {
+		mdp->irq_enabled = true;
 		sh_eth_write(ndev, mdp->cd->eesipr_value, EESIPR);
+	}
 
 	/* PAUSE Prohibition */
 	val = (sh_eth_read(ndev, ECMR) & ECMR_DM) |
@@ -1653,7 +1655,12 @@ static irqreturn_t sh_eth_interrupt(int irq, void *netdev)
 	if (intr_status & (EESR_RX_CHECK | cd->tx_check | cd->eesr_err_check))
 		ret = IRQ_HANDLED;
 	else
-		goto other_irq;
+		goto out;
+
+	if (!likely(mdp->irq_enabled)) {
+		sh_eth_write(ndev, 0, EESIPR);
+		goto out;
+	}
 
 	if (intr_status & EESR_RX_CHECK) {
 		if (napi_schedule_prep(&mdp->napi)) {
@@ -1684,7 +1691,7 @@ static irqreturn_t sh_eth_interrupt(int irq, void *netdev)
 		sh_eth_error(ndev, intr_status);
 	}
 
-other_irq:
+out:
 	spin_unlock(&mdp->lock);
 
 	return ret;
@@ -1712,7 +1719,8 @@ static int sh_eth_poll(struct napi_struct *napi, int budget)
 	napi_complete(napi);
 
 	/* Reenable Rx interrupts */
-	sh_eth_write(ndev, mdp->cd->eesipr_value, EESIPR);
+	if (mdp->irq_enabled)
+		sh_eth_write(ndev, mdp->cd->eesipr_value, EESIPR);
 out:
 	return budget - quota;
 }
@@ -1968,40 +1976,52 @@ static int sh_eth_set_ringparam(struct net_device *ndev,
 		return -EINVAL;
 
 	if (netif_running(ndev)) {
+		netif_device_detach(ndev);
 		netif_tx_disable(ndev);
-		/* Disable interrupts by clearing the interrupt mask. */
+
+		/* Serialise with the interrupt handler and NAPI, then
+		 * disable interrupts.  We have to clear the
+		 * irq_enabled flag first to ensure that interrupts
+		 * won't be re-enabled.
+		 */
+		mdp->irq_enabled = false;
+		synchronize_irq(ndev->irq);
+		napi_synchronize(&mdp->napi);
 		sh_eth_write(ndev, 0x0000, EESIPR);
+
 		/* Stop the chip's Tx and Rx processes. */
 		sh_eth_write(ndev, 0, EDTRR);
 		sh_eth_write(ndev, 0, EDRRR);
-		synchronize_irq(ndev->irq);
-	}
 
-	/* Free all the skbuffs in the Rx queue. */
-	sh_eth_ring_free(ndev);
-	/* Free DMA buffer */
-	sh_eth_free_dma_buffer(mdp);
+		/* Free all the skbuffs in the Rx queue. */
+		sh_eth_ring_free(ndev);
+		/* Free DMA buffer */
+		sh_eth_free_dma_buffer(mdp);
+	}
 
 	/* Set new parameters */
 	mdp->num_rx_ring = ring->rx_pending;
 	mdp->num_tx_ring = ring->tx_pending;
 
-	ret = sh_eth_ring_init(ndev);
-	if (ret < 0) {
-		netdev_err(ndev, "%s: sh_eth_ring_init failed.\n", __func__);
-		return ret;
-	}
-	ret = sh_eth_dev_init(ndev, false);
-	if (ret < 0) {
-		netdev_err(ndev, "%s: sh_eth_dev_init failed.\n", __func__);
-		return ret;
-	}
-
 	if (netif_running(ndev)) {
+		ret = sh_eth_ring_init(ndev);
+		if (ret < 0) {
+			netdev_err(ndev, "%s: sh_eth_ring_init failed.\n",
+				   __func__);
+			return ret;
+		}
+		ret = sh_eth_dev_init(ndev, false);
+		if (ret < 0) {
+			netdev_err(ndev, "%s: sh_eth_dev_init failed.\n",
+				   __func__);
+			return ret;
+		}
+
+		mdp->irq_enabled = true;
 		sh_eth_write(ndev, mdp->cd->eesipr_value, EESIPR);
 		/* Setting the Rx mode will start the Rx process. */
 		sh_eth_write(ndev, EDRRR_R, EDRRR);
-		netif_wake_queue(ndev);
+		netif_device_attach(ndev);
 	}
 
 	return 0;
@@ -2117,6 +2137,9 @@ static int sh_eth_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	}
 	spin_unlock_irqrestore(&mdp->lock, flags);
 
+	if (skb_padto(skb, ETH_ZLEN))
+		return NETDEV_TX_OK;
+
 	entry = mdp->cur_tx % mdp->num_tx_ring;
 	mdp->tx_skbuff[entry] = skb;
 	txdesc = &mdp->tx_ring[entry];
@@ -2126,10 +2149,7 @@ static int sh_eth_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 				 skb->len + 2);
 	txdesc->addr = dma_map_single(&ndev->dev, skb->data, skb->len,
 				      DMA_TO_DEVICE);
-	if (skb->len < ETH_ZLEN)
-		txdesc->buffer_length = ETH_ZLEN;
-	else
-		txdesc->buffer_length = skb->len;
+	txdesc->buffer_length = skb->len;
 
 	if (entry >= mdp->num_tx_ring - 1)
 		txdesc->status |= cpu_to_edmac(mdp, TD_TACT | TD_TDLE);
@@ -2181,7 +2201,13 @@ static int sh_eth_close(struct net_device *ndev)
 
 	netif_stop_queue(ndev);
 
-	/* Disable interrupts by clearing the interrupt mask. */
+	/* Serialise with the interrupt handler and NAPI, then disable
+	 * interrupts.  We have to clear the irq_enabled flag first to
+	 * ensure that interrupts won't be re-enabled.
+	 */
+	mdp->irq_enabled = false;
+	synchronize_irq(ndev->irq);
+	napi_disable(&mdp->napi);
 	sh_eth_write(ndev, 0x0000, EESIPR);
 
 	/* Stop the chip's Tx and Rx processes. */
@@ -2198,8 +2224,6 @@ static int sh_eth_close(struct net_device *ndev)
 
 	free_irq(ndev->irq, ndev);
 
-	napi_disable(&mdp->napi);
-
 	/* Free all the skbuffs in the Rx queue. */
 	sh_eth_ring_free(ndev);
 

drivers/net/ethernet/renesas/sh_eth.h

@@ -513,6 +513,7 @@ struct sh_eth_private {
 	u32 rx_buf_sz;			/* Based on MTU+slack. */
 	int edmac_endian;
 	struct napi_struct napi;
+	bool irq_enabled;
 	/* MII transceiver section. */
 	u32 phy_id;			/* PHY ID */
 	struct mii_bus *mii_bus;	/* MDIO bus control */