[PATCH A 00/12] Freescale ethernet driver updates

[PATCH A 00/12] Freescale ethernet driver updates

[Russell King - ARM Linux]

David,

Here's the first batch of patches for the Freescale FEC ethernet driver.
They require the previously applied "net: fec: Don't clear IPV6 header
checksum field when IP accelerator enable" patch.

I'll mail further patches tomorrow, once I hear back from you.

Many thanks.

 drivers/net/ethernet/freescale/fec.h      |   1 -
 drivers/net/ethernet/freescale/fec_main.c | 137 +++++++++++++++++-------------
 2 files changed, 79 insertions(+), 59 deletions(-)

-- 
FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.

[PATCH A 01/12] net: fec: iMX6 FEC does not support half-duplex gigabit

[Russell King]

The iMX6 gigabit FEC does not support half-duplex gigabit operation.
Phys attacked to the FEC may support this, and we currently do nothing
to disable this feature.  This may result in an invalid configuration.
Mask out phy support for gigabit half-duplex operation.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/net/ethernet/freescale/fec_main.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 77037fd377b8..a91fe68030e6 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1667,6 +1667,7 @@ static int fec_enet_mii_probe(struct net_device *ndev)
 	/* mask with MAC supported features */
 	if (id_entry->driver_data & FEC_QUIRK_HAS_GBIT) {
 		phy_dev->supported &= PHY_GBIT_FEATURES;
+		phy_dev->supported &= ~SUPPORTED_1000baseT_Half;
 #if !defined(CONFIG_M5272)
 		phy_dev->supported |= SUPPORTED_Pause;
 #endif
-- 
1.8.3.1

Re: [PATCH A 01/12] net: fec: iMX6 FEC does not support half-duplex gigabit

[Sergei Shtylyov]

Hello.

On 07/08/2014 03:22 AM, Russell King wrote:

> The iMX6 gigabit FEC does not support half-duplex gigabit operation.
> Phys attacked to the FEC may support this, and we currently do nothing

    s/attacked/attached/. Perhaps Dave can fix when applying...

> to disable this feature.  This may result in an invalid configuration.
> Mask out phy support for gigabit half-duplex operation.

> Acked-by: Fugang Duan <B38611@freescale.com>
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

WBR, Sergei

[PATCH A 02/12] net: fec: fix ethtool set_pauseparam duplex bug

[Russell King]

Setting the pause parameters causes a running network interface to be
restarted.  However, the restart forces the FEC into half-duplex mode,
whether or not the remote end is in half-duplex mode.  Misconfigured
duplex mode is a known source of problems on a link.

Fix this by always preserving the duplex mode on configuration changes.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/net/ethernet/freescale/fec_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index a91fe68030e6..045ea71f2b59 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1897,7 +1897,7 @@ static int fec_enet_set_pauseparam(struct net_device *ndev,
 		phy_start_aneg(fep->phy_dev);
 	}
 	if (netif_running(ndev))
-		fec_restart(ndev, 0);
+		fec_restart(ndev, fep->full_duplex);
 
 	return 0;
 }
-- 
1.8.3.1

[PATCH A 03/12] net: fec: fix interrupt handling races

[Russell King]

While running: while :; do iperf -c <HOST> -P 4; done, transmit timeouts
are regularly reported.  With the tx ring dumping in place, we can see
that all entries are in use, and the hardware has finished transmitting
these packets.  However, the driver has not reclaimed these ring
entries.

This can occur if the interrupt handler is invoked at the wrong moment -
eg:

	CPU0				CPU1
	fec_enet_tx()
					interrupt, IEVENT = FEC_ENET_TXF
					FEC_ENET_TXF cleared
					napi_schedule_prep()
	napi_complete()

The result is that we clear the transmit interrupt, but we don't trigger
any cleaning of the transmit ring.  Instead, use a different strategy:

- When receiving a transmit or receive interrupt, disable both tx and rx
  interrupts, but do not acknowledge them.  Schedule a napi poll.  Don't
  loop.

- When we are polled, read IEVENT, acknowledging the pending transmit
  and receive interrupts, before then going on to process the
  appropriate rings.

This allows us to avoid the race, and has a number of other advantages:
- we cut down on the number of transmit interrupts we have to process.
- we only look at the rings which have pending events.
- we gain additional throughput: the iperf total bandwidth increases
  from about 180Mbps to 240Mbps:

[  3]  0.0-10.0 sec  68.1 MBytes  57.0 Mbits/sec
[  5]  0.0-10.0 sec  72.4 MBytes  60.5 Mbits/sec
[  4]  0.0-10.1 sec  76.1 MBytes  63.5 Mbits/sec
[  6]  0.0-10.1 sec  71.9 MBytes  59.9 Mbits/sec
[SUM]  0.0-10.1 sec   288 MBytes   241 Mbits/sec

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/net/ethernet/freescale/fec_main.c | 40 +++++++++++++++++--------------
 1 file changed, 22 insertions(+), 18 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 045ea71f2b59..4e695b742030 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1369,29 +1369,25 @@ fec_enet_interrupt(int irq, void *dev_id)
 {
 	struct net_device *ndev = dev_id;
 	struct fec_enet_private *fep = netdev_priv(ndev);
+	const unsigned napi_mask = FEC_ENET_RXF | FEC_ENET_TXF;
 	uint int_events;
 	irqreturn_t ret = IRQ_NONE;
 
-	do {
-		int_events = readl(fep->hwp + FEC_IEVENT);
-		writel(int_events, fep->hwp + FEC_IEVENT);
+	int_events = readl(fep->hwp + FEC_IEVENT);
+	writel(int_events & ~napi_mask, fep->hwp + FEC_IEVENT);
 
-		if (int_events & (FEC_ENET_RXF | FEC_ENET_TXF)) {
-			ret = IRQ_HANDLED;
+	if (int_events & napi_mask) {
+		ret = IRQ_HANDLED;
 
-			/* Disable the RX interrupt */
-			if (napi_schedule_prep(&fep->napi)) {
-				writel(FEC_RX_DISABLED_IMASK,
-					fep->hwp + FEC_IMASK);
-				__napi_schedule(&fep->napi);
-			}
-		}
+		/* Disable the NAPI interrupts */
+		writel(FEC_ENET_MII, fep->hwp + FEC_IMASK);
+		napi_schedule(&fep->napi);
+	}
 
-		if (int_events & FEC_ENET_MII) {
-			ret = IRQ_HANDLED;
-			complete(&fep->mdio_done);
-		}
-	} while (int_events);
+	if (int_events & FEC_ENET_MII) {
+		ret = IRQ_HANDLED;
+		complete(&fep->mdio_done);
+	}
 
 	return ret;
 }
@@ -1399,8 +1395,16 @@ fec_enet_interrupt(int irq, void *dev_id)
 static int fec_enet_rx_napi(struct napi_struct *napi, int budget)
 {
 	struct net_device *ndev = napi->dev;
-	int pkts = fec_enet_rx(ndev, budget);
 	struct fec_enet_private *fep = netdev_priv(ndev);
+	int pkts;
+
+	/*
+	 * Clear any pending transmit or receive interrupts before
+	 * processing the rings to avoid racing with the hardware.
+	 */
+	writel(FEC_ENET_RXF | FEC_ENET_TXF, fep->hwp + FEC_IEVENT);
+
+	pkts = fec_enet_rx(ndev, budget);
 
 	fec_enet_tx(ndev);
 
-- 
1.8.3.1

[PATCH A 04/12] net: fec: use netif_tx_disable() rather than netif_stop_queue()

[Russell King]

We use netif_stop_queue() in several places where we want to ensure that
the start_xmit function is not running.  netif_stop_queue() is not
sufficient to achieve that - it merely sets a flag to indicate that the
transmit queue(s) should not be run.

netif_tx_disable() gives this guarantee, since it takes the transmit
queue lock while marking the queue stopped.  This will wait for the
transmit function to complete before returning.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/net/ethernet/freescale/fec_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 4e695b742030..cb9ced738607 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -834,7 +834,7 @@ fec_restart(struct net_device *ndev, int duplex)
 	if (netif_running(ndev)) {
 		netif_device_detach(ndev);
 		napi_disable(&fep->napi);
-		netif_stop_queue(ndev);
+		netif_tx_disable(ndev);
 		netif_tx_lock_bh(ndev);
 	}
 
@@ -2181,7 +2181,7 @@ fec_enet_close(struct net_device *ndev)
 	/* Don't know what to do yet. */
 	napi_disable(&fep->napi);
 	fep->opened = 0;
-	netif_stop_queue(ndev);
+	netif_tx_disable(ndev);
 	fec_stop(ndev);
 
 	if (fep->phy_dev) {
-- 
1.8.3.1

[PATCH A 05/12] net: fec: remove checking for NULL phy_dev in fec_enet_close()

[Russell King]

fep->phy_dev can not be NULL here for two reasons:
- fec_enet_open() will have successfully connected the phy, or will have
  failed.
- fec_enet_open() will have called phy_start(fep->phy_dev), which
  unconditionally dereferences this pointer.

If it were to be NULL here, then fec_enet_open() will have already
oopsed.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/net/ethernet/freescale/fec_main.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index cb9ced738607..6a03d7eced4d 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -2184,10 +2184,8 @@ fec_enet_close(struct net_device *ndev)
 	netif_tx_disable(ndev);
 	fec_stop(ndev);
 
-	if (fep->phy_dev) {
-		phy_stop(fep->phy_dev);
-		phy_disconnect(fep->phy_dev);
-	}
+	phy_stop(fep->phy_dev);
+	phy_disconnect(fep->phy_dev);
 
 	fec_enet_clk_enable(ndev, false);
 	pinctrl_pm_select_sleep_state(&fep->pdev->dev);
-- 
1.8.3.1

[PATCH A 06/12] net: fec: ensure that a disconnected phy isn't configured

[Russell King]

When we disconnect from a phy, we should forget our pointer to it so we
don't accidentally try to configure it.  We handle a NULL phy pointer
correctly in most places, except fec_enet_set_pauseparam().  Fix this
too.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/net/ethernet/freescale/fec_main.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 6a03d7eced4d..cf805468eecc 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1875,6 +1875,9 @@ static int fec_enet_set_pauseparam(struct net_device *ndev,
 {
 	struct fec_enet_private *fep = netdev_priv(ndev);
 
+	if (!fep->phy_dev)
+		return -ENODEV;
+
 	if (pause->tx_pause != pause->rx_pause) {
 		netdev_info(ndev,
 			"hardware only support enable/disable both tx and rx");
@@ -2186,6 +2189,7 @@ fec_enet_close(struct net_device *ndev)
 
 	phy_stop(fep->phy_dev);
 	phy_disconnect(fep->phy_dev);
+	fep->phy_dev = NULL;
 
 	fec_enet_clk_enable(ndev, false);
 	pinctrl_pm_select_sleep_state(&fep->pdev->dev);
-- 
1.8.3.1

[PATCH A 07/12] net: fec: stop the phy before shutting down the MAC

[Russell King]

When the network interface goes down, stop the phy to prevent further
link up status changes before taking the MAC or netif sections down.
This prevents further reception of link up events which could
potentially call fec_restart().

Since phy_stop() takes the mutex which adjust_link() runs under, we
also ensure that adjust_link() will not already be processing a link
up event.

We also need to do this when suspending as well - we don't want a
mis-timed phy state change to restart the MAC after we have stopped
it for suspend, and thus need to restart the phy when resuming.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/net/ethernet/freescale/fec_main.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index cf805468eecc..e0a1ac1826b7 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -2181,13 +2181,14 @@ fec_enet_close(struct net_device *ndev)
 {
 	struct fec_enet_private *fep = netdev_priv(ndev);
 
+	phy_stop(fep->phy_dev);
+
 	/* Don't know what to do yet. */
 	napi_disable(&fep->napi);
 	fep->opened = 0;
 	netif_tx_disable(ndev);
 	fec_stop(ndev);
 
-	phy_stop(fep->phy_dev);
 	phy_disconnect(fep->phy_dev);
 	fep->phy_dev = NULL;
 
@@ -2669,6 +2670,7 @@ fec_suspend(struct device *dev)
 	struct fec_enet_private *fep = netdev_priv(ndev);
 
 	if (netif_running(ndev)) {
+		phy_stop(fep->phy_dev);
 		fec_stop(ndev);
 		netif_device_detach(ndev);
 	}
@@ -2702,6 +2704,7 @@ fec_resume(struct device *dev)
 	if (netif_running(ndev)) {
 		fec_restart(ndev, fep->full_duplex);
 		netif_device_attach(ndev);
+		phy_start(fep->phy_dev);
 	}
 
 	return 0;
-- 
1.8.3.1

[PATCH A 08/12] net: fec: remove useless fep->opened

[Russell King]

napi_disable() waits until the NAPI processing has completed, and then
prevents any further polls.  At this point, the driver then clears
fep->opened.  The NAPI poll function uses this to stop processing in
the receive path.  Hence, it will never see this variable cleared,
because the NAPI poll has to complete before it will be cleared.

Therefore, this variable serves no purpose, so let's remove it.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/net/ethernet/freescale/fec.h      | 1 -
 drivers/net/ethernet/freescale/fec_main.c | 5 -----
 2 files changed, 6 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index 671d080105a7..96d2a18f1b99 100644
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -308,7 +308,6 @@ struct fec_enet_private {
 
 	struct	platform_device *pdev;
 
-	int	opened;
 	int	dev_id;
 
 	/* Phylib and MDIO interface */
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index e0a1ac1826b7..309aa2ff8cc9 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1215,9 +1215,6 @@ fec_enet_rx(struct net_device *ndev, int budget)
 		if ((status & BD_ENET_RX_LAST) == 0)
 			netdev_err(ndev, "rcv is not +last\n");
 
-		if (!fep->opened)
-			goto rx_processing_done;
-
 		/* Check for errors. */
 		if (status & (BD_ENET_RX_LG | BD_ENET_RX_SH | BD_ENET_RX_NO |
 			   BD_ENET_RX_CR | BD_ENET_RX_OV)) {
@@ -2172,7 +2169,6 @@ fec_enet_open(struct net_device *ndev)
 	napi_enable(&fep->napi);
 	phy_start(fep->phy_dev);
 	netif_start_queue(ndev);
-	fep->opened = 1;
 	return 0;
 }
 
@@ -2185,7 +2181,6 @@ fec_enet_close(struct net_device *ndev)
 
 	/* Don't know what to do yet. */
 	napi_disable(&fep->napi);
-	fep->opened = 0;
 	netif_tx_disable(ndev);
 	fec_stop(ndev);
 
-- 
1.8.3.1

[PATCH A 09/12] net: fec: make rx skb handling more robust

[Russell King]

Allocate, and then map the receive skb before writing any data to the
ring descriptor or storing the skb.  When freeing the receive ring
entries, unmap and free the skb, and then clear the stored skb pointer.

This means we have ring data and skb pointer in one of two states:
either both fully setup, or nothing setup.

This simplifies the cleanup, as we can use just the skb pointer to
indicate whether the descriptor is setup, and thus avoids potentially
calling dma_unmap_single() on a DMA error value.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/net/ethernet/freescale/fec_main.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 309aa2ff8cc9..70853a59627a 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -2066,12 +2066,12 @@ static void fec_enet_free_buffers(struct net_device *ndev)
 	bdp = fep->rx_bd_base;
 	for (i = 0; i < fep->rx_ring_size; i++) {
 		skb = fep->rx_skbuff[i];
-
-		if (bdp->cbd_bufaddr)
+		fep->rx_skbuff[i] = NULL;
+		if (skb) {
 			dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr,
 					FEC_ENET_RX_FRSIZE, DMA_FROM_DEVICE);
-		if (skb)
 			dev_kfree_skb(skb);
+		}
 		bdp = fec_enet_get_nextdesc(bdp, fep);
 	}
 
@@ -2089,21 +2089,26 @@ static int fec_enet_alloc_buffers(struct net_device *ndev)
 
 	bdp = fep->rx_bd_base;
 	for (i = 0; i < fep->rx_ring_size; i++) {
+		dma_addr_t addr;
+
 		skb = netdev_alloc_skb(ndev, FEC_ENET_RX_FRSIZE);
 		if (!skb) {
 			fec_enet_free_buffers(ndev);
 			return -ENOMEM;
 		}
-		fep->rx_skbuff[i] = skb;
 
-		bdp->cbd_bufaddr = dma_map_single(&fep->pdev->dev, skb->data,
+		addr = dma_map_single(&fep->pdev->dev, skb->data,
 				FEC_ENET_RX_FRSIZE, DMA_FROM_DEVICE);
-		if (dma_mapping_error(&fep->pdev->dev, bdp->cbd_bufaddr)) {
+		if (dma_mapping_error(&fep->pdev->dev, addr)) {
+			dev_kfree_skb(skb);
 			fec_enet_free_buffers(ndev);
 			if (net_ratelimit())
 				netdev_err(ndev, "Rx DMA memory map failed\n");
 			return -ENOMEM;
 		}
+
+		fep->rx_skbuff[i] = skb;
+		bdp->cbd_bufaddr = addr;
 		bdp->cbd_sc = BD_ENET_RX_EMPTY;
 
 		if (fep->bufdesc_ex) {
-- 
1.8.3.1

[PATCH A 10/12] net: fec: clean up transmit descriptor setup

[Russell King]

Avoid writing any state until we're certain we can proceed with the
transmission: this avoids writing mapping error address values to the
descriptors, or setting the skbuff pointer until we have successfully
mapped the skb.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/net/ethernet/freescale/fec_main.c | 33 +++++++++++++++++--------------
 1 file changed, 18 insertions(+), 15 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 70853a59627a..9c5570a3e32e 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -373,6 +373,7 @@ fec_enet_txq_submit_frag_skb(struct sk_buff *skb, struct net_device *ndev)
 	skb_frag_t *this_frag;
 	unsigned int index;
 	void *bufaddr;
+	dma_addr_t addr;
 	int i;
 
 	for (frag = 0; frag < nr_frags; frag++) {
@@ -415,15 +416,16 @@ fec_enet_txq_submit_frag_skb(struct sk_buff *skb, struct net_device *ndev)
 				swap_buffer(bufaddr, frag_len);
 		}
 
-		bdp->cbd_bufaddr = dma_map_single(&fep->pdev->dev, bufaddr,
-						frag_len, DMA_TO_DEVICE);
-		if (dma_mapping_error(&fep->pdev->dev, bdp->cbd_bufaddr)) {
+		addr = dma_map_single(&fep->pdev->dev, bufaddr, frag_len,
+				      DMA_TO_DEVICE);
+		if (dma_mapping_error(&fep->pdev->dev, addr)) {
 			dev_kfree_skb_any(skb);
 			if (net_ratelimit())
 				netdev_err(ndev, "Tx DMA memory map failed\n");
 			goto dma_mapping_error;
 		}
 
+		bdp->cbd_bufaddr = addr;
 		bdp->cbd_datlen = frag_len;
 		bdp->cbd_sc = status;
 	}
@@ -450,6 +452,7 @@ static int fec_enet_txq_submit_skb(struct sk_buff *skb, struct net_device *ndev)
 	int nr_frags = skb_shinfo(skb)->nr_frags;
 	struct bufdesc *bdp, *last_bdp;
 	void *bufaddr;
+	dma_addr_t addr;
 	unsigned short status;
 	unsigned short buflen;
 	unsigned int estatus = 0;
@@ -490,12 +493,9 @@ static int fec_enet_txq_submit_skb(struct sk_buff *skb, struct net_device *ndev)
 			swap_buffer(bufaddr, buflen);
 	}
 
-	/* Push the data cache so the CPM does not get stale memory
-	 * data.
-	 */
-	bdp->cbd_bufaddr = dma_map_single(&fep->pdev->dev, bufaddr,
-					buflen, DMA_TO_DEVICE);
-	if (dma_mapping_error(&fep->pdev->dev, bdp->cbd_bufaddr)) {
+	/* Push the data cache so the CPM does not get stale memory data. */
+	addr = dma_map_single(&fep->pdev->dev, bufaddr, buflen, DMA_TO_DEVICE);
+	if (dma_mapping_error(&fep->pdev->dev, addr)) {
 		dev_kfree_skb_any(skb);
 		if (net_ratelimit())
 			netdev_err(ndev, "Tx DMA memory map failed\n");
@@ -537,6 +537,7 @@ static int fec_enet_txq_submit_skb(struct sk_buff *skb, struct net_device *ndev)
 	fep->tx_skbuff[index] = skb;
 
 	bdp->cbd_datlen = buflen;
+	bdp->cbd_bufaddr = addr;
 
 	/* Send it on its way.  Tell FEC it's ready, interrupt when done,
 	 * it's the last BD of the frame, and to put the CRC on the end.
@@ -570,12 +571,12 @@ fec_enet_txq_put_data_tso(struct sk_buff *skb, struct net_device *ndev,
 	struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;
 	unsigned short status;
 	unsigned int estatus = 0;
+	dma_addr_t addr;
 
 	status = bdp->cbd_sc;
 	status &= ~BD_ENET_TX_STATS;
 
 	status |= (BD_ENET_TX_TC | BD_ENET_TX_READY);
-	bdp->cbd_datlen = size;
 
 	if (((unsigned long) data) & FEC_ALIGNMENT ||
 		id_entry->driver_data & FEC_QUIRK_SWAP_FRAME) {
@@ -586,15 +587,17 @@ fec_enet_txq_put_data_tso(struct sk_buff *skb, struct net_device *ndev,
 			swap_buffer(data, size);
 	}
 
-	bdp->cbd_bufaddr = dma_map_single(&fep->pdev->dev, data,
-					size, DMA_TO_DEVICE);
-	if (dma_mapping_error(&fep->pdev->dev, bdp->cbd_bufaddr)) {
+	addr = dma_map_single(&fep->pdev->dev, data, size, DMA_TO_DEVICE);
+	if (dma_mapping_error(&fep->pdev->dev, addr)) {
 		dev_kfree_skb_any(skb);
 		if (net_ratelimit())
 			netdev_err(ndev, "Tx DMA memory map failed\n");
 		return NETDEV_TX_BUSY;
 	}
 
+	bdp->cbd_datlen = size;
+	bdp->cbd_bufaddr = addr;
+
 	if (fep->bufdesc_ex) {
 		if (skb->ip_summed == CHECKSUM_PARTIAL)
 			estatus |= BD_ENET_TX_PINS | BD_ENET_TX_IINS;
@@ -801,7 +804,7 @@ static void fec_enet_bd_init(struct net_device *dev)
 
 		/* Initialize the BD for every fragment in the page. */
 		bdp->cbd_sc = 0;
-		if (bdp->cbd_bufaddr && fep->tx_skbuff[i]) {
+		if (fep->tx_skbuff[i]) {
 			dev_kfree_skb_any(fep->tx_skbuff[i]);
 			fep->tx_skbuff[i] = NULL;
 		}
@@ -1100,6 +1103,7 @@ fec_enet_tx(struct net_device *ndev)
 		index = fec_enet_get_bd_index(fep->tx_bd_base, bdp, fep);
 
 		skb = fep->tx_skbuff[index];
+		fep->tx_skbuff[index] = NULL;
 		if (!IS_TSO_HEADER(fep, bdp->cbd_bufaddr))
 			dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr,
 					bdp->cbd_datlen, DMA_TO_DEVICE);
@@ -1154,7 +1158,6 @@ fec_enet_tx(struct net_device *ndev)
 
 		/* Free the sk buffer associated with this last transmit */
 		dev_kfree_skb_any(skb);
-		fep->tx_skbuff[index] = NULL;
 
 		fep->dirty_tx = bdp;
 
-- 
1.8.3.1

[PATCH A 11/12] net: fec: ensure fec_enet_free_buffers() properly cleans the rings

[Russell King]

Ensure that we do not double-free any allocations, and that any transmit
skbuffs are properly freed when we clean up the rings.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/net/ethernet/freescale/fec_main.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 9c5570a3e32e..5499bd8ad0a5 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -2079,8 +2079,13 @@ static void fec_enet_free_buffers(struct net_device *ndev)
 	}
 
 	bdp = fep->tx_bd_base;
-	for (i = 0; i < fep->tx_ring_size; i++)
+	for (i = 0; i < fep->tx_ring_size; i++) {
 		kfree(fep->tx_bounce[i]);
+		fep->tx_bounce[i] = NULL;
+		skb = fep->tx_skbuff[i];
+		fep->tx_skbuff[i] = NULL;
+		dev_kfree_skb(skb);
+	}
 }
 
 static int fec_enet_alloc_buffers(struct net_device *ndev)
-- 
1.8.3.1

[PATCH A 12/12] net: fec: fix missing kmalloc() failure check in fec_enet_alloc_buffers()

[Russell King]

fec_enet_alloc_buffers() assumes that kmalloc() will never fail, which
is an invalid assumption.  Fix this by implementing a common error
cleanup path, and use it to also clean up after failed bounce buffer
allocation.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/net/ethernet/freescale/fec_main.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 5499bd8ad0a5..f43c388e2eb9 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -2100,19 +2100,16 @@ static int fec_enet_alloc_buffers(struct net_device *ndev)
 		dma_addr_t addr;
 
 		skb = netdev_alloc_skb(ndev, FEC_ENET_RX_FRSIZE);
-		if (!skb) {
-			fec_enet_free_buffers(ndev);
-			return -ENOMEM;
-		}
+		if (!skb)
+			goto err_alloc;
 
 		addr = dma_map_single(&fep->pdev->dev, skb->data,
 				FEC_ENET_RX_FRSIZE, DMA_FROM_DEVICE);
 		if (dma_mapping_error(&fep->pdev->dev, addr)) {
 			dev_kfree_skb(skb);
-			fec_enet_free_buffers(ndev);
 			if (net_ratelimit())
 				netdev_err(ndev, "Rx DMA memory map failed\n");
-			return -ENOMEM;
+			goto err_alloc;
 		}
 
 		fep->rx_skbuff[i] = skb;
@@ -2134,6 +2131,8 @@ static int fec_enet_alloc_buffers(struct net_device *ndev)
 	bdp = fep->tx_bd_base;
 	for (i = 0; i < fep->tx_ring_size; i++) {
 		fep->tx_bounce[i] = kmalloc(FEC_ENET_TX_FRSIZE, GFP_KERNEL);
+		if (!fep->tx_bounce[i])
+			goto err_alloc;
 
 		bdp->cbd_sc = 0;
 		bdp->cbd_bufaddr = 0;
@@ -2151,6 +2150,10 @@ static int fec_enet_alloc_buffers(struct net_device *ndev)
 	bdp->cbd_sc |= BD_SC_WRAP;
 
 	return 0;
+
+ err_alloc:
+	fec_enet_free_buffers(ndev);
+	return -ENOMEM;
 }
 
 static int
-- 
1.8.3.1

Re: [PATCH A 00/12] Freescale ethernet driver updates

[David Miller]

From: Russell King - ARM Linux <linux@arm.linux.org.uk>
Date: Tue, 8 Jul 2014 00:21:48 +0100

> Here's the first batch of patches for the Freescale FEC ethernet driver.
> They require the previously applied "net: fec: Don't clear IPV6 header
> checksum field when IP accelerator enable" patch.
> 
> I'll mail further patches tomorrow, once I hear back from you.

Applied to net-next, thanks.