[PATCH v3 01/11] net: calxedaxgmac: remove NETIF_F_FRAGLIST setting

[PATCH v3 01/11] net: calxedaxgmac: remove NETIF_F_FRAGLIST setting

[Rob Herring]

From: Rob Herring <rob.herring@calxeda.com>

The xgmac does not actually handle frag lists, so this option should not
be set. It does not appear to have had any impact though.

Reported-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
---
 drivers/net/ethernet/calxeda/xgmac.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c
index 7cb148c..71f6720 100644
--- a/drivers/net/ethernet/calxeda/xgmac.c
+++ b/drivers/net/ethernet/calxeda/xgmac.c
@@ -1759,7 +1759,7 @@ static int xgmac_probe(struct platform_device *pdev)
 	if (device_can_wakeup(priv->device))
 		priv->wolopts = WAKE_MAGIC;	/* Magic Frame as default */
 
-	ndev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
+	ndev->hw_features = NETIF_F_SG | NETIF_F_HIGHDMA;
 	if (readl(priv->base + XGMAC_DMA_HW_FEATURE) & DMA_HW_FEAT_TXCOESEL)
 		ndev->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
 				     NETIF_F_RXCSUM;
-- 
1.8.1.2

[PATCH v3 02/11] net: calxedaxgmac: read correct field in xgmac_desc_get_buf_len

[Rob Herring]

From: Rob Herring <rob.herring@calxeda.com>

xgmac_desc_get_buf_len appears to have a copy/paste error. flags is the
wrong field to read. We should be reading buf_size field. cpu_to_le32
should also be le32_to_cpu. This never really mattered as this function
is only used for DMA mapping calls which happen to be nops with coherent
DMA.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
---
 drivers/net/ethernet/calxeda/xgmac.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c
index 71f6720..d41af68 100644
--- a/drivers/net/ethernet/calxeda/xgmac.c
+++ b/drivers/net/ethernet/calxeda/xgmac.c
@@ -421,7 +421,7 @@ static inline void desc_set_buf_len(struct xgmac_dma_desc *p, u32 buf_sz)
 
 static inline int desc_get_buf_len(struct xgmac_dma_desc *p)
 {
-	u32 len = cpu_to_le32(p->flags);
+	u32 len = le32_to_cpu(p->buf_size);
 	return (len & DESC_BUFFER1_SZ_MASK) +
 		((len & DESC_BUFFER2_SZ_MASK) >> DESC_BUFFER2_SZ_OFFSET);
 }
-- 
1.8.1.2

[PATCH v3 03/11] net: calxedaxgmac: fix race between xgmac_tx_complete and xgmac_tx_err

[Rob Herring]

From: Rob Herring <rob.herring@calxeda.com>

It is possible for the xgmac_tx_complete to run concurrently with
xgmac_tx_err since there are no locks. Fix this by moving the tx
error handling to a workqueue so we can disable napi while we reset
the transmitter.

Reported-by: Andreas Herrmann <andreas.herrmann@calxeda.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
---
 drivers/net/ethernet/calxeda/xgmac.c | 38 +++++++++++++++++-------------------
 1 file changed, 18 insertions(+), 20 deletions(-)

diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c
index d41af68..df7e3e2 100644
--- a/drivers/net/ethernet/calxeda/xgmac.c
+++ b/drivers/net/ethernet/calxeda/xgmac.c
@@ -393,6 +393,7 @@ struct xgmac_priv {
 	char rx_pause;
 	char tx_pause;
 	int wolopts;
+	struct work_struct tx_timeout_work;
 };
 
 /* XGMAC Configuration Settings */
@@ -897,21 +898,18 @@ static void xgmac_tx_complete(struct xgmac_priv *priv)
 		netif_wake_queue(priv->dev);
 }
 
-/**
- * xgmac_tx_err:
- * @priv: pointer to the private device structure
- * Description: it cleans the descriptors and restarts the transmission
- * in case of errors.
- */
-static void xgmac_tx_err(struct xgmac_priv *priv)
+static void xgmac_tx_timeout_work(struct work_struct *work)
 {
-	u32 reg, value, inten;
+	u32 reg, value;
+	struct xgmac_priv *priv =
+		container_of(work, struct xgmac_priv, tx_timeout_work);
 
-	netif_stop_queue(priv->dev);
+	napi_disable(&priv->napi);
 
-	inten = readl(priv->base + XGMAC_DMA_INTR_ENA);
 	writel(0, priv->base + XGMAC_DMA_INTR_ENA);
 
+	netif_tx_lock(priv->dev);
+
 	reg = readl(priv->base + XGMAC_DMA_CONTROL);
 	writel(reg & ~DMA_CONTROL_ST, priv->base + XGMAC_DMA_CONTROL);
 	do {
@@ -927,9 +925,15 @@ static void xgmac_tx_err(struct xgmac_priv *priv)
 
 	writel(DMA_STATUS_TU | DMA_STATUS_TPS | DMA_STATUS_NIS | DMA_STATUS_AIS,
 		priv->base + XGMAC_DMA_STATUS);
-	writel(inten, priv->base + XGMAC_DMA_INTR_ENA);
 
+	netif_tx_unlock(priv->dev);
 	netif_wake_queue(priv->dev);
+
+	napi_enable(&priv->napi);
+
+	/* Enable interrupts */
+	writel(DMA_INTR_DEFAULT_MASK, priv->base + XGMAC_DMA_STATUS);
+	writel(DMA_INTR_DEFAULT_MASK, priv->base + XGMAC_DMA_INTR_ENA);
 }
 
 static int xgmac_hw_init(struct net_device *dev)
@@ -1225,9 +1229,7 @@ static int xgmac_poll(struct napi_struct *napi, int budget)
 static void xgmac_tx_timeout(struct net_device *dev)
 {
 	struct xgmac_priv *priv = netdev_priv(dev);
-
-	/* Clear Tx resources and restart transmitting again */
-	xgmac_tx_err(priv);
+	schedule_work(&priv->tx_timeout_work);
 }
 
 /**
@@ -1366,7 +1368,6 @@ static irqreturn_t xgmac_pmt_interrupt(int irq, void *dev_id)
 static irqreturn_t xgmac_interrupt(int irq, void *dev_id)
 {
 	u32 intr_status;
-	bool tx_err = false;
 	struct net_device *dev = (struct net_device *)dev_id;
 	struct xgmac_priv *priv = netdev_priv(dev);
 	struct xgmac_extra_stats *x = &priv->xstats;
@@ -1396,16 +1397,12 @@ static irqreturn_t xgmac_interrupt(int irq, void *dev_id)
 		if (intr_status & DMA_STATUS_TPS) {
 			netdev_err(priv->dev, "transmit process stopped\n");
 			x->tx_process_stopped++;
-			tx_err = true;
+			schedule_work(&priv->tx_timeout_work);
 		}
 		if (intr_status & DMA_STATUS_FBI) {
 			netdev_err(priv->dev, "fatal bus error\n");
 			x->fatal_bus_error++;
-			tx_err = true;
 		}
-
-		if (tx_err)
-			xgmac_tx_err(priv);
 	}
 
 	/* TX/RX NORMAL interrupts */
@@ -1708,6 +1705,7 @@ static int xgmac_probe(struct platform_device *pdev)
 	ndev->netdev_ops = &xgmac_netdev_ops;
 	SET_ETHTOOL_OPS(ndev, &xgmac_ethtool_ops);
 	spin_lock_init(&priv->stats_lock);
+	INIT_WORK(&priv->tx_timeout_work, xgmac_tx_timeout_work);
 
 	priv->device = &pdev->dev;
 	priv->dev = ndev;
-- 
1.8.1.2

[PATCH v3 04/11] net: calxedaxgmac: fix possible skb free before tx complete

[Rob Herring]

From: Rob Herring <rob.herring@calxeda.com>

The TX completion code may have freed an skb before the entire sg list
was transmitted. The DMA unmap calls for the fragments could also get
skipped. Now set the skb pointer on every entry in the ring, not just
the head of the sg list. We then use the FS (first segment) bit in the
descriptors to determine skb head vs. fragment.

This also fixes similar bug in xgmac_free_tx_skbufs where clean-up of
a sg list that wraps at the end of the ring buffer would not get
unmapped.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
---
 drivers/net/ethernet/calxeda/xgmac.c | 55 ++++++++++++++++--------------------
 1 file changed, 24 insertions(+), 31 deletions(-)

diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c
index df7e3e2..64854ad 100644
--- a/drivers/net/ethernet/calxeda/xgmac.c
+++ b/drivers/net/ethernet/calxeda/xgmac.c
@@ -470,6 +470,11 @@ static inline int desc_get_tx_ls(struct xgmac_dma_desc *p)
 	return le32_to_cpu(p->flags) & TXDESC_LAST_SEG;
 }
 
+static inline int desc_get_tx_fs(struct xgmac_dma_desc *p)
+{
+	return le32_to_cpu(p->flags) & TXDESC_FIRST_SEG;
+}
+
 static inline u32 desc_get_buf_addr(struct xgmac_dma_desc *p)
 {
 	return le32_to_cpu(p->buf1_addr);
@@ -796,7 +801,7 @@ static void xgmac_free_rx_skbufs(struct xgmac_priv *priv)
 
 static void xgmac_free_tx_skbufs(struct xgmac_priv *priv)
 {
-	int i, f;
+	int i;
 	struct xgmac_dma_desc *p;
 
 	if (!priv->tx_skbuff)
@@ -807,16 +812,15 @@ static void xgmac_free_tx_skbufs(struct xgmac_priv *priv)
 			continue;
 
 		p = priv->dma_tx + i;
-		dma_unmap_single(priv->device, desc_get_buf_addr(p),
-				 desc_get_buf_len(p), DMA_TO_DEVICE);
-
-		for (f = 0; f < skb_shinfo(priv->tx_skbuff[i])->nr_frags; f++) {
-			p = priv->dma_tx + i++;
+		if (desc_get_tx_fs(p))
+			dma_unmap_single(priv->device, desc_get_buf_addr(p),
+					 desc_get_buf_len(p), DMA_TO_DEVICE);
+		else
 			dma_unmap_page(priv->device, desc_get_buf_addr(p),
 				       desc_get_buf_len(p), DMA_TO_DEVICE);
-		}
 
-		dev_kfree_skb_any(priv->tx_skbuff[i]);
+		if (desc_get_tx_ls(p))
+			dev_kfree_skb_any(priv->tx_skbuff[i]);
 		priv->tx_skbuff[i] = NULL;
 	}
 }
@@ -853,8 +857,6 @@ static void xgmac_free_dma_desc_rings(struct xgmac_priv *priv)
  */
 static void xgmac_tx_complete(struct xgmac_priv *priv)
 {
-	int i;
-
 	while (dma_ring_cnt(priv->tx_head, priv->tx_tail, DMA_TX_RING_SZ)) {
 		unsigned int entry = priv->tx_tail;
 		struct sk_buff *skb = priv->tx_skbuff[entry];
@@ -864,33 +866,24 @@ static void xgmac_tx_complete(struct xgmac_priv *priv)
 		if (desc_get_owner(p))
 			break;
 
-		/* Verify tx error by looking at the last segment */
-		if (desc_get_tx_ls(p))
-			desc_get_tx_status(priv, p);
-
 		netdev_dbg(priv->dev, "tx ring: curr %d, dirty %d\n",
 			priv->tx_head, priv->tx_tail);
 
-		dma_unmap_single(priv->device, desc_get_buf_addr(p),
-				 desc_get_buf_len(p), DMA_TO_DEVICE);
-
-		priv->tx_skbuff[entry] = NULL;
-		priv->tx_tail = dma_ring_incr(entry, DMA_TX_RING_SZ);
-
-		if (!skb) {
-			continue;
-		}
-
-		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
-			entry = priv->tx_tail = dma_ring_incr(priv->tx_tail,
-							      DMA_TX_RING_SZ);
-			p = priv->dma_tx + priv->tx_tail;
-
+		if (desc_get_tx_fs(p))
+			dma_unmap_single(priv->device, desc_get_buf_addr(p),
+					 desc_get_buf_len(p), DMA_TO_DEVICE);
+		else
 			dma_unmap_page(priv->device, desc_get_buf_addr(p),
 				       desc_get_buf_len(p), DMA_TO_DEVICE);
+
+		/* Check tx error on the last segment */
+		if (desc_get_tx_ls(p)) {
+			desc_get_tx_status(priv, p);
+			dev_kfree_skb(skb);
 		}
 
-		dev_kfree_skb(skb);
+		priv->tx_skbuff[entry] = NULL;
+		priv->tx_tail = dma_ring_incr(entry, DMA_TX_RING_SZ);
 	}
 
 	if (dma_ring_space(priv->tx_head, priv->tx_tail, DMA_TX_RING_SZ) >
@@ -1110,7 +1103,7 @@ static netdev_tx_t xgmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 		entry = dma_ring_incr(entry, DMA_TX_RING_SZ);
 		desc = priv->dma_tx + entry;
-		priv->tx_skbuff[entry] = NULL;
+		priv->tx_skbuff[entry] = skb;
 
 		desc_set_buf_addr_and_size(desc, paddr, len);
 		if (i < (nfrags - 1))
-- 
1.8.1.2

[PATCH v3 05/11] net: calxedaxgmac: update ring buffer tx_head after barriers

[Rob Herring]

From: Rob Herring <rob.herring@calxeda.com>

Ensure that the descriptor writes are visible before the ring buffer head
is updated. Since writel is a barrier, we can simply update the head after
the writel.

Reported-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
---
 drivers/net/ethernet/calxeda/xgmac.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c
index 64854ad..f630855 100644
--- a/drivers/net/ethernet/calxeda/xgmac.c
+++ b/drivers/net/ethernet/calxeda/xgmac.c
@@ -1121,9 +1121,10 @@ static netdev_tx_t xgmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	wmb();
 	desc_set_tx_owner(first, desc_flags | TXDESC_FIRST_SEG);
 
+	writel(1, priv->base + XGMAC_DMA_TX_POLL);
+
 	priv->tx_head = dma_ring_incr(entry, DMA_TX_RING_SZ);
 
-	writel(1, priv->base + XGMAC_DMA_TX_POLL);
 	if (dma_ring_space(priv->tx_head, priv->tx_tail, DMA_TX_RING_SZ) <
 	    MAX_SKB_FRAGS)
 		netif_stop_queue(dev);
-- 
1.8.1.2

[PATCH v3 06/11] net: calxedaxgmac: fix race with tx queue stop/wake

[Rob Herring]

From: Rob Herring <rob.herring@calxeda.com>

Since the xgmac transmit start and completion work locklessly, it is
possible for xgmac_xmit to stop the tx queue after the xgmac_tx_complete
has run resulting in the tx queue never being woken up. Fix this by
ensuring that ring buffer index updates are visible and recheck the ring
space after stopping the queue. Also fix an off-by-one bug where we need
to stop the queue when the ring buffer space is equal to MAX_SKB_FRAGS.

The implementation used here was copied from
drivers/net/ethernet/broadcom/tg3.c.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
---
v3:
- Fix off-by-one bug in queue stopping

v2:
- drop netif_tx_lock
- use netif_start_queue instead of netif_wake_queue

 drivers/net/ethernet/calxeda/xgmac.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c
index f630855..5d0b61a 100644
--- a/drivers/net/ethernet/calxeda/xgmac.c
+++ b/drivers/net/ethernet/calxeda/xgmac.c
@@ -410,6 +410,9 @@ struct xgmac_priv {
 #define dma_ring_space(h, t, s)	CIRC_SPACE(h, t, s)
 #define dma_ring_cnt(h, t, s)	CIRC_CNT(h, t, s)
 
+#define tx_dma_ring_space(p) \
+	dma_ring_space((p)->tx_head, (p)->tx_tail, DMA_TX_RING_SZ)
+
 /* XGMAC Descriptor Access Helpers */
 static inline void desc_set_buf_len(struct xgmac_dma_desc *p, u32 buf_sz)
 {
@@ -886,8 +889,10 @@ static void xgmac_tx_complete(struct xgmac_priv *priv)
 		priv->tx_tail = dma_ring_incr(entry, DMA_TX_RING_SZ);
 	}
 
-	if (dma_ring_space(priv->tx_head, priv->tx_tail, DMA_TX_RING_SZ) >
-	    MAX_SKB_FRAGS)
+	/* Ensure tx_tail is visible to xgmac_xmit */
+	smp_mb();
+	if (unlikely(netif_queue_stopped(priv->dev) &&
+	    (tx_dma_ring_space(priv) > MAX_SKB_FRAGS)))
 		netif_wake_queue(priv->dev);
 }
 
@@ -1125,10 +1130,15 @@ static netdev_tx_t xgmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	priv->tx_head = dma_ring_incr(entry, DMA_TX_RING_SZ);
 
-	if (dma_ring_space(priv->tx_head, priv->tx_tail, DMA_TX_RING_SZ) <
-	    MAX_SKB_FRAGS)
+	/* Ensure tx_head update is visible to tx completion */
+	smp_mb();
+	if (unlikely(tx_dma_ring_space(priv) <= MAX_SKB_FRAGS)) {
 		netif_stop_queue(dev);
-
+		/* Ensure netif_stop_queue is visible to tx completion */
+		smp_mb();
+		if (tx_dma_ring_space(priv) > MAX_SKB_FRAGS)
+			netif_start_queue(dev);
+	}
 	return NETDEV_TX_OK;
 }
 
-- 
1.8.1.2

[PATCH v3 07/11] net: calxedaxgmac: enable interrupts after napi_enable

[Rob Herring]

From: Rob Herring <rob.herring@calxeda.com>

Fix a race condition where the interrupt handler may have called
napi_schedule before napi_enable is called. This would disable interrupts
and never actually schedule napi to run.

Reported-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
---
 drivers/net/ethernet/calxeda/xgmac.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c
index 5d0b61a..73d3f83 100644
--- a/drivers/net/ethernet/calxeda/xgmac.c
+++ b/drivers/net/ethernet/calxeda/xgmac.c
@@ -959,9 +959,7 @@ static int xgmac_hw_init(struct net_device *dev)
 		DMA_BUS_MODE_FB | DMA_BUS_MODE_ATDS | DMA_BUS_MODE_AAL;
 	writel(value, ioaddr + XGMAC_DMA_BUS_MODE);
 
-	/* Enable interrupts */
-	writel(DMA_INTR_DEFAULT_MASK, ioaddr + XGMAC_DMA_STATUS);
-	writel(DMA_INTR_DEFAULT_MASK, ioaddr + XGMAC_DMA_INTR_ENA);
+	writel(0, ioaddr + XGMAC_DMA_INTR_ENA);
 
 	/* Mask power mgt interrupt */
 	writel(XGMAC_INT_STAT_PMTIM, ioaddr + XGMAC_INT_STAT);
@@ -1029,6 +1027,10 @@ static int xgmac_open(struct net_device *dev)
 	napi_enable(&priv->napi);
 	netif_start_queue(dev);
 
+	/* Enable interrupts */
+	writel(DMA_INTR_DEFAULT_MASK, ioaddr + XGMAC_DMA_STATUS);
+	writel(DMA_INTR_DEFAULT_MASK, ioaddr + XGMAC_DMA_INTR_ENA);
+
 	return 0;
 }
 
-- 
1.8.1.2

[PATCH v3 08/11] net: calxedaxgmac: fix various errors in xgmac_set_rx_mode

[Rob Herring]

From: Rob Herring <rob.herring@calxeda.com>

Fix xgmac_set_rx_mode to handle several conditions that were not handled
correctly as Lennert Buytenhek describes:

If we have, say, 100 unicast addresses, and 5 multicast addresses, the
unicast address count check will evaluate to true, and set use_hash to
true.  The multicast address check will however evaluate to false, and
use_hash won't be set to true again, and XGMAC_FRAME_FILTER_HMC won't
be OR'd into XGMAC_FRAME_FILTER, but since use_hash was still true
from the unicast check, netdev_for_each_mc_addr() will program the
multicast addresses into the hash table instead of using the MAC
address registers, but since the HMC bit wasn't set, the hash table
won't be checked for multicast addresses on receive, and we'll stop
receiving multicast packets entirely.

Also, there is no code that zeroes out MAC address registers reg..31
at the end of this function, meaning that under the right conditions,
unicast/multicast addresses that were previously in the filter but
were then deleted won't be cleared out.

Reported-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
---
 drivers/net/ethernet/calxeda/xgmac.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c
index 73d3f83..0cff9e3 100644
--- a/drivers/net/ethernet/calxeda/xgmac.c
+++ b/drivers/net/ethernet/calxeda/xgmac.c
@@ -618,10 +618,15 @@ static void xgmac_set_mac_addr(void __iomem *ioaddr, unsigned char *addr,
 {
 	u32 data;
 
-	data = (addr[5] << 8) | addr[4] | (num ? XGMAC_ADDR_AE : 0);
-	writel(data, ioaddr + XGMAC_ADDR_HIGH(num));
-	data = (addr[3] << 24) | (addr[2] << 16) | (addr[1] << 8) | addr[0];
-	writel(data, ioaddr + XGMAC_ADDR_LOW(num));
+	if (addr) {
+		data = (addr[5] << 8) | addr[4] | (num ? XGMAC_ADDR_AE : 0);
+		writel(data, ioaddr + XGMAC_ADDR_HIGH(num));
+		data = (addr[3] << 24) | (addr[2] << 16) | (addr[1] << 8) | addr[0];
+		writel(data, ioaddr + XGMAC_ADDR_LOW(num));
+	} else {
+		writel(0, ioaddr + XGMAC_ADDR_HIGH(num));
+		writel(0, ioaddr + XGMAC_ADDR_LOW(num));
+	}
 }
 
 static void xgmac_get_mac_addr(void __iomem *ioaddr, unsigned char *addr,
@@ -1294,6 +1299,8 @@ static void xgmac_set_rx_mode(struct net_device *dev)
 	if ((netdev_mc_count(dev) + reg - 1) > XGMAC_MAX_FILTER_ADDR) {
 		use_hash = true;
 		value |= XGMAC_FRAME_FILTER_HMC | XGMAC_FRAME_FILTER_HPF;
+	} else {
+		use_hash = false;
 	}
 	netdev_for_each_mc_addr(ha, dev) {
 		if (use_hash) {
@@ -1310,6 +1317,8 @@ static void xgmac_set_rx_mode(struct net_device *dev)
 	}
 
 out:
+	for (i = reg; i < XGMAC_MAX_FILTER_ADDR; i++)
+		xgmac_set_mac_addr(ioaddr, NULL, reg);
 	for (i = 0; i < XGMAC_NUM_HASH; i++)
 		writel(hash_filter[i], ioaddr + XGMAC_HASH(i));
 
-- 
1.8.1.2

[PATCH v3 09/11] net: calxedaxgmac: remove some unused statistic counters

[Rob Herring]

From: Rob Herring <rob.herring@calxeda.com>

rx_sa_filter_fail and tx_undeflow events are unused and impossible
to occur based on how the h/w is used. We never filter on source MAC
address and TX store and forward mode prevents underflow events.

Reported-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
---
 drivers/net/ethernet/calxeda/xgmac.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c
index 0cff9e3..04c585c 100644
--- a/drivers/net/ethernet/calxeda/xgmac.c
+++ b/drivers/net/ethernet/calxeda/xgmac.c
@@ -353,11 +353,9 @@ struct xgmac_extra_stats {
 	/* Receive errors */
 	unsigned long rx_watchdog;
 	unsigned long rx_da_filter_fail;
-	unsigned long rx_sa_filter_fail;
 	unsigned long rx_payload_error;
 	unsigned long rx_ip_header_error;
 	/* Tx/Rx IRQ errors */
-	unsigned long tx_undeflow;
 	unsigned long tx_process_stopped;
 	unsigned long rx_buf_unav;
 	unsigned long rx_process_stopped;
@@ -1581,7 +1579,6 @@ static const struct xgmac_stats xgmac_gstrings_stats[] = {
 	XGMAC_STAT(rx_payload_error),
 	XGMAC_STAT(rx_ip_header_error),
 	XGMAC_STAT(rx_da_filter_fail),
-	XGMAC_STAT(rx_sa_filter_fail),
 	XGMAC_STAT(fatal_bus_error),
 	XGMAC_HW_STAT(rx_watchdog, XGMAC_MMC_RXWATCHDOG),
 	XGMAC_HW_STAT(tx_vlan, XGMAC_MMC_TXVLANFRAME),
-- 
1.8.1.2

[PATCH v3 10/11] net: calxedaxgmac: fix rx DMA mapping API size mismatches

[Rob Herring]

From: Rob Herring <rob.herring@calxeda.com>

Fix the mismatch in the DMA mapping and unmapping sizes for receive. The
unmap size must be equal to the map size and should not be the actual
received frame length. The map size should also be adjusted by the
NET_IP_ALIGN size since the h/w buffer size (dma_buf_sz) includes this
offset.

Also, add a missing dma_mapping_error check in xgmac_rx_refill.

Reported-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
---
 drivers/net/ethernet/calxeda/xgmac.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c
index 04c585c..cd5010b 100644
--- a/drivers/net/ethernet/calxeda/xgmac.c
+++ b/drivers/net/ethernet/calxeda/xgmac.c
@@ -695,9 +695,14 @@ static void xgmac_rx_refill(struct xgmac_priv *priv)
 			if (unlikely(skb == NULL))
 				break;
 
-			priv->rx_skbuff[entry] = skb;
 			paddr = dma_map_single(priv->device, skb->data,
-					       bufsz, DMA_FROM_DEVICE);
+					       priv->dma_buf_sz - NET_IP_ALIGN,
+					       DMA_FROM_DEVICE);
+			if (dma_mapping_error(priv->device, paddr)) {
+				dev_kfree_skb_any(skb);
+				break;
+			}
+			priv->rx_skbuff[entry] = skb;
 			desc_set_buf_addr(p, paddr, priv->dma_buf_sz);
 		}
 
@@ -794,13 +799,14 @@ static void xgmac_free_rx_skbufs(struct xgmac_priv *priv)
 		return;
 
 	for (i = 0; i < DMA_RX_RING_SZ; i++) {
-		if (priv->rx_skbuff[i] == NULL)
+		struct sk_buff *skb = priv->rx_skbuff[i];
+		if (skb == NULL)
 			continue;
 
 		p = priv->dma_rx + i;
 		dma_unmap_single(priv->device, desc_get_buf_addr(p),
-				 priv->dma_buf_sz, DMA_FROM_DEVICE);
-		dev_kfree_skb_any(priv->rx_skbuff[i]);
+				 priv->dma_buf_sz - NET_IP_ALIGN, DMA_FROM_DEVICE);
+		dev_kfree_skb_any(skb);
 		priv->rx_skbuff[i] = NULL;
 	}
 }
@@ -1187,7 +1193,7 @@ static int xgmac_rx(struct xgmac_priv *priv, int limit)
 
 		skb_put(skb, frame_len);
 		dma_unmap_single(priv->device, desc_get_buf_addr(p),
-				 frame_len, DMA_FROM_DEVICE);
+				 priv->dma_buf_sz - NET_IP_ALIGN, DMA_FROM_DEVICE);
 
 		skb->protocol = eth_type_trans(skb, priv->dev);
 		skb->ip_summed = ip_checksum;
-- 
1.8.1.2

[PATCH v3 11/11] net: calxedaxgmac: fix xgmac_xmit DMA mapping error handling

[Rob Herring]

From: Rob Herring <rob.herring@calxeda.com>

On a DMA mapping error in xgmac_xmit, we should simply free the skb and
return NETDEV_TX_OK rather than -EIO. In the case of errors in mapping
frags, we need to undo everything that has been setup.

Reported-by: Andreas Herrmann <andreas.herrmann@calxeda.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
---
 drivers/net/ethernet/calxeda/xgmac.c | 31 ++++++++++++++++++++++++++-----
 1 file changed, 26 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c
index cd5010b..78d6d6b 100644
--- a/drivers/net/ethernet/calxeda/xgmac.c
+++ b/drivers/net/ethernet/calxeda/xgmac.c
@@ -466,6 +466,13 @@ static inline void desc_set_tx_owner(struct xgmac_dma_desc *p, u32 flags)
 	p->flags = cpu_to_le32(tmpflags);
 }
 
+static inline void desc_clear_tx_owner(struct xgmac_dma_desc *p)
+{
+	u32 tmpflags = le32_to_cpu(p->flags);
+	tmpflags &= TXDESC_END_RING;
+	p->flags = cpu_to_le32(tmpflags);
+}
+
 static inline int desc_get_tx_ls(struct xgmac_dma_desc *p)
 {
 	return le32_to_cpu(p->flags) & TXDESC_LAST_SEG;
@@ -1100,7 +1107,7 @@ static netdev_tx_t xgmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	paddr = dma_map_single(priv->device, skb->data, len, DMA_TO_DEVICE);
 	if (dma_mapping_error(priv->device, paddr)) {
 		dev_kfree_skb(skb);
-		return -EIO;
+		return NETDEV_TX_OK;
 	}
 	priv->tx_skbuff[entry] = skb;
 	desc_set_buf_addr_and_size(desc, paddr, len);
@@ -1112,10 +1119,8 @@ static netdev_tx_t xgmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 		paddr = skb_frag_dma_map(priv->device, frag, 0, len,
 					 DMA_TO_DEVICE);
-		if (dma_mapping_error(priv->device, paddr)) {
-			dev_kfree_skb(skb);
-			return -EIO;
-		}
+		if (dma_mapping_error(priv->device, paddr))
+			goto dma_err;
 
 		entry = dma_ring_incr(entry, DMA_TX_RING_SZ);
 		desc = priv->dma_tx + entry;
@@ -1151,6 +1156,22 @@ static netdev_tx_t xgmac_xmit(struct sk_buff *skb, struct net_device *dev)
 			netif_start_queue(dev);
 	}
 	return NETDEV_TX_OK;
+
+dma_err:
+	entry = priv->tx_head;
+	for ( ; i > 0; i--) {
+		entry = dma_ring_incr(entry, DMA_TX_RING_SZ);
+		desc = priv->dma_tx + entry;
+		priv->tx_skbuff[entry] = NULL;
+		dma_unmap_page(priv->device, desc_get_buf_addr(desc),
+			       desc_get_buf_len(desc), DMA_TO_DEVICE);
+		desc_clear_tx_owner(desc);
+	}
+	desc = first;
+	dma_unmap_single(priv->device, desc_get_buf_addr(desc),
+			 desc_get_buf_len(desc), DMA_TO_DEVICE);
+	dev_kfree_skb(skb);
+	return NETDEV_TX_OK;
 }
 
 static int xgmac_rx(struct xgmac_priv *priv, int limit)
-- 
1.8.1.2

Re: [PATCH v3 06/11] net: calxedaxgmac: fix race with tx queue stop/wake

[Ben Hutchings]

On Fri, 2013-08-30 at 16:49 -0500, Rob Herring wrote:
> From: Rob Herring <rob.herring@calxeda.com>
> 
> Since the xgmac transmit start and completion work locklessly, it is
> possible for xgmac_xmit to stop the tx queue after the xgmac_tx_complete
> has run resulting in the tx queue never being woken up. Fix this by
> ensuring that ring buffer index updates are visible and recheck the ring
> space after stopping the queue. Also fix an off-by-one bug where we need
> to stop the queue when the ring buffer space is equal to MAX_SKB_FRAGS.
> 
> The implementation used here was copied from
> drivers/net/ethernet/broadcom/tg3.c.
> 
> Signed-off-by: Rob Herring <rob.herring@calxeda.com>

Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>

> ---
> v3:
> - Fix off-by-one bug in queue stopping
> 
> v2:
> - drop netif_tx_lock
> - use netif_start_queue instead of netif_wake_queue
> 
>  drivers/net/ethernet/calxeda/xgmac.c | 20 +++++++++++++++-----
>  1 file changed, 15 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c
> index f630855..5d0b61a 100644
> --- a/drivers/net/ethernet/calxeda/xgmac.c
> +++ b/drivers/net/ethernet/calxeda/xgmac.c
> @@ -410,6 +410,9 @@ struct xgmac_priv {
>  #define dma_ring_space(h, t, s)	CIRC_SPACE(h, t, s)
>  #define dma_ring_cnt(h, t, s)	CIRC_CNT(h, t, s)
>  
> +#define tx_dma_ring_space(p) \
> +	dma_ring_space((p)->tx_head, (p)->tx_tail, DMA_TX_RING_SZ)
> +
>  /* XGMAC Descriptor Access Helpers */
>  static inline void desc_set_buf_len(struct xgmac_dma_desc *p, u32 buf_sz)
>  {
> @@ -886,8 +889,10 @@ static void xgmac_tx_complete(struct xgmac_priv *priv)
>  		priv->tx_tail = dma_ring_incr(entry, DMA_TX_RING_SZ);
>  	}
>  
> -	if (dma_ring_space(priv->tx_head, priv->tx_tail, DMA_TX_RING_SZ) >
> -	    MAX_SKB_FRAGS)
> +	/* Ensure tx_tail is visible to xgmac_xmit */
> +	smp_mb();
> +	if (unlikely(netif_queue_stopped(priv->dev) &&
> +	    (tx_dma_ring_space(priv) > MAX_SKB_FRAGS)))
>  		netif_wake_queue(priv->dev);
>  }
>  
> @@ -1125,10 +1130,15 @@ static netdev_tx_t xgmac_xmit(struct sk_buff *skb, struct net_device *dev)
>  
>  	priv->tx_head = dma_ring_incr(entry, DMA_TX_RING_SZ);
>  
> -	if (dma_ring_space(priv->tx_head, priv->tx_tail, DMA_TX_RING_SZ) <
> -	    MAX_SKB_FRAGS)
> +	/* Ensure tx_head update is visible to tx completion */
> +	smp_mb();
> +	if (unlikely(tx_dma_ring_space(priv) <= MAX_SKB_FRAGS)) {
>  		netif_stop_queue(dev);
> -
> +		/* Ensure netif_stop_queue is visible to tx completion */
> +		smp_mb();
> +		if (tx_dma_ring_space(priv) > MAX_SKB_FRAGS)
> +			netif_start_queue(dev);
> +	}
>  	return NETDEV_TX_OK;
>  }
>  

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

Re: [PATCH v3 01/11] net: calxedaxgmac: remove NETIF_F_FRAGLIST setting

[David Miller]

Series applied, thanks.

In the future, when you send more than one patch at a time, always provide
an initial "[PATCH 00/NN] " posting which gives a top-level overview
description of your patch series and what it achieves.

You can look at what other developers do on this list for examples.

Thank you.