[PATCH B 00/10] Freescale ethernet driver updates (part 2)

[PATCH B 00/10] Freescale ethernet driver updates (part 2)

[Russell King - ARM Linux]

David,

Here's the second batch of patches for the Freescale FEC ethernet driver,
based upon the previous set of patches.  One further set of 7 patches
remains.

Many thanks.

 drivers/net/ethernet/freescale/fec_main.c | 127 ++++++++++++++++++++----------
 1 file changed, 84 insertions(+), 43 deletions(-)

[PATCH B 01/10] net: fec: improve safety of suspend/resume/transmit timeout paths

[Russell King]

We should hold the rtnl lock while suspending, resuming or processing
the transmit timeout to ensure that nothing will interfere while we
bring up, take down or restart the hardware.  The transmit timeout
could run if we're preempted during suspend.

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, 7 insertions(+)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index f43c388e2eb9..1cd71a8d9996 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1068,8 +1068,10 @@ static void fec_enet_work(struct work_struct *work)
 
 	if (fep->delay_work.timeout) {
 		fep->delay_work.timeout = false;
+		rtnl_lock();
 		fec_restart(fep->netdev, fep->full_duplex);
 		netif_wake_queue(fep->netdev);
+		rtnl_unlock();
 	}
 
 	if (fep->delay_work.trig_tx) {
@@ -2680,11 +2682,14 @@ fec_suspend(struct device *dev)
 	struct net_device *ndev = dev_get_drvdata(dev);
 	struct fec_enet_private *fep = netdev_priv(ndev);
 
+	rtnl_lock();
 	if (netif_running(ndev)) {
 		phy_stop(fep->phy_dev);
 		fec_stop(ndev);
 		netif_device_detach(ndev);
 	}
+	rtnl_unlock();
+
 	fec_enet_clk_enable(ndev, false);
 	pinctrl_pm_select_sleep_state(&fep->pdev->dev);
 
@@ -2712,11 +2717,13 @@ fec_resume(struct device *dev)
 	if (ret)
 		goto failed_clk;
 
+	rtnl_lock();
 	if (netif_running(ndev)) {
 		fec_restart(ndev, fep->full_duplex);
 		netif_device_attach(ndev);
 		phy_start(fep->phy_dev);
 	}
+	rtnl_unlock();
 
 	return 0;
 
-- 
1.8.3.1

[PATCH B 02/10] net: fec: ensure fec_enet_close() copes with resume failure

[Russell King]

When the FEC is suspended, the device is detached.  Upon resume failure,
the device is left in detached mode, possibly with some of the required
clocks not running.  We don't want to be poking the device in that state
because as it may cause bus errors.

If the device is marked detached, avoid calling fec_stop().

This depends upon: "net:fec: improve safety of suspend/resume paths"

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 1cd71a8d9996..03785cd14b7c 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -2197,10 +2197,10 @@ fec_enet_close(struct net_device *ndev)
 
 	phy_stop(fep->phy_dev);
 
-	/* Don't know what to do yet. */
 	napi_disable(&fep->napi);
 	netif_tx_disable(ndev);
-	fec_stop(ndev);
+	if (netif_device_present(ndev))
+		fec_stop(ndev);
 
 	phy_disconnect(fep->phy_dev);
 	fep->phy_dev = NULL;
-- 
1.8.3.1

[PATCH B 03/10] net: fec: only restart or stop the device if it is present and running

[Russell King]

Avoid calling fec_restart() or fec_stop() while the device is down
or not present (iow suspended.)

Although the ndo_timeout method will only be called if the device is
present and running, we defer this to a work queue.  The work queue
can run independently, and so needs to repeat these checks to ensure
that a restart doesn't occur after the device has been taken down or
detached for suspend.  In this case, we call fec_restart() in the
resume path, so nothing is lost.

For fec_set_features, we add a call to fec_restart() in fec_enet_open()
to ensure that the hardware is appropriate programmed when the interface
is opened.  fec_set_features() call should not occur while we're
suspended, so we don't have to worry about that case.

The adjust_link needs similar treatment - this also is called from a
work queue, which may be run independently after we have taken the
device down and detached it.  In this case, we just mark the link
down and take no further action.  We will reset things appropriately
once the device is up and running again, at which point we will receive
another adjust_link callback.

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 | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 03785cd14b7c..bfb2bb00c493 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1065,12 +1065,15 @@ static void fec_enet_work(struct work_struct *work)
 		container_of(work,
 			     struct fec_enet_private,
 			     delay_work.delay_work.work);
+	struct net_device *ndev = fep->netdev;
 
 	if (fep->delay_work.timeout) {
 		fep->delay_work.timeout = false;
 		rtnl_lock();
-		fec_restart(fep->netdev, fep->full_duplex);
-		netif_wake_queue(fep->netdev);
+		if (netif_device_present(ndev) || netif_running(ndev)) {
+			fec_restart(ndev, fep->full_duplex);
+			netif_wake_queue(ndev);
+		}
 		rtnl_unlock();
 	}
 
@@ -1504,7 +1507,14 @@ static void fec_enet_adjust_link(struct net_device *ndev)
 		return;
 	}
 
-	if (phy_dev->link) {
+	/*
+	 * If the netdev is down, or is going down, we're not interested
+	 * in link state events, so just mark our idea of the link as down
+	 * and ignore the event.
+	 */
+	if (!netif_running(ndev) || !netif_device_present(ndev)) {
+		fep->link = 0;
+	} else if (phy_dev->link) {
 		if (!fep->link) {
 			fep->link = phy_dev->link;
 			status_change = 1;
@@ -2184,6 +2194,7 @@ fec_enet_open(struct net_device *ndev)
 		return ret;
 	}
 
+	fec_restart(ndev, fep->full_duplex);
 	napi_enable(&fep->napi);
 	phy_start(fep->phy_dev);
 	netif_start_queue(ndev);
@@ -2350,8 +2361,6 @@ static int fec_set_features(struct net_device *netdev,
 			fec_stop(netdev);
 			fec_restart(netdev, fep->phy_dev->duplex);
 			netif_wake_queue(netdev);
-		} else {
-			fec_restart(netdev, fep->phy_dev->duplex);
 		}
 	}
 
-- 
1.8.3.1

[PATCH B 04/10] net: fec: move calls to quiesce/resume packet processing out of fec_restart()

[Russell King]

Move the calls to quiesce and resume packet processing out of
fec_restart() to its call sites.  This is the first step in a two stage
clean up of this code, where we just move the calls out of fec_restart()
without changing them.  Not everywhere needs to issue these calls, and
not everywhere needs all of these calls to be issued.

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 | 64 ++++++++++++++++++++++---------
 1 file changed, 45 insertions(+), 19 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index bfb2bb00c493..b71b7491f38f 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -818,9 +818,10 @@ static void fec_enet_bd_init(struct net_device *dev)
 	fep->dirty_tx = bdp;
 }
 
-/* This function is called to start or restart the FEC during a link
- * change.  This only happens when switching between half and full
- * duplex.
+/*
+ * This function is called to start or restart the FEC during a link
+ * change, transmit timeout, or to reconfigure the FEC.  The network
+ * packet processing for this device must be stopped before this call.
  */
 static void
 fec_restart(struct net_device *ndev, int duplex)
@@ -834,13 +835,6 @@ fec_restart(struct net_device *ndev, int duplex)
 	u32 rcntl = OPT_FRAME_SIZE | 0x04;
 	u32 ecntl = 0x2; /* ETHEREN */
 
-	if (netif_running(ndev)) {
-		netif_device_detach(ndev);
-		napi_disable(&fep->napi);
-		netif_tx_disable(ndev);
-		netif_tx_lock_bh(ndev);
-	}
-
 	/* Whack a reset.  We should wait for this. */
 	writel(1, fep->hwp + FEC_ECNTRL);
 	udelay(10);
@@ -1009,13 +1003,6 @@ fec_restart(struct net_device *ndev, int duplex)
 
 	/* Enable interrupts we wish to service */
 	writel(FEC_DEFAULT_IMASK, fep->hwp + FEC_IMASK);
-
-	if (netif_running(ndev)) {
-		netif_tx_unlock_bh(ndev);
-		netif_wake_queue(ndev);
-		napi_enable(&fep->napi);
-		netif_device_attach(ndev);
-	}
 }
 
 static void
@@ -1071,8 +1058,15 @@ static void fec_enet_work(struct work_struct *work)
 		fep->delay_work.timeout = false;
 		rtnl_lock();
 		if (netif_device_present(ndev) || netif_running(ndev)) {
+			netif_device_detach(ndev);
+			napi_disable(&fep->napi);
+			netif_tx_disable(ndev);
+			netif_tx_lock_bh(ndev);
 			fec_restart(ndev, fep->full_duplex);
+			netif_tx_unlock_bh(ndev);
 			netif_wake_queue(ndev);
+			napi_enable(&fep->napi);
+			netif_device_attach(ndev);
 		}
 		rtnl_unlock();
 	}
@@ -1529,8 +1523,17 @@ static void fec_enet_adjust_link(struct net_device *ndev)
 		}
 
 		/* if any of the above changed restart the FEC */
-		if (status_change)
+		if (status_change) {
+			netif_device_detach(ndev);
+			napi_disable(&fep->napi);
+			netif_tx_disable(ndev);
+			netif_tx_lock_bh(ndev);
 			fec_restart(ndev, phy_dev->duplex);
+			netif_tx_unlock_bh(ndev);
+			netif_wake_queue(ndev);
+			napi_enable(&fep->napi);
+			netif_device_attach(ndev);
+		}
 	} else {
 		if (fep->link) {
 			fec_stop(ndev);
@@ -1915,8 +1918,17 @@ static int fec_enet_set_pauseparam(struct net_device *ndev,
 			fec_stop(ndev);
 		phy_start_aneg(fep->phy_dev);
 	}
-	if (netif_running(ndev))
+	if (netif_running(ndev)) {
+		netif_device_detach(ndev);
+		napi_disable(&fep->napi);
+		netif_tx_disable(ndev);
+		netif_tx_lock_bh(ndev);
 		fec_restart(ndev, fep->full_duplex);
+		netif_tx_unlock_bh(ndev);
+		netif_wake_queue(ndev);
+		napi_enable(&fep->napi);
+		netif_device_attach(ndev);
+	}
 
 	return 0;
 }
@@ -2359,8 +2371,15 @@ static int fec_set_features(struct net_device *netdev,
 
 		if (netif_running(netdev)) {
 			fec_stop(netdev);
+			netif_device_detach(netdev);
+			napi_disable(&fep->napi);
+			netif_tx_disable(netdev);
+			netif_tx_lock_bh(netdev);
 			fec_restart(netdev, fep->phy_dev->duplex);
+			netif_tx_unlock_bh(netdev);
 			netif_wake_queue(netdev);
+			napi_enable(&fep->napi);
+			netif_device_attach(netdev);
 		}
 	}
 
@@ -2728,7 +2747,14 @@ fec_resume(struct device *dev)
 
 	rtnl_lock();
 	if (netif_running(ndev)) {
+		netif_device_detach(ndev);
+		napi_disable(&fep->napi);
+		netif_tx_disable(ndev);
+		netif_tx_lock_bh(ndev);
 		fec_restart(ndev, fep->full_duplex);
+		netif_tx_unlock_bh(ndev);
+		netif_wake_queue(ndev);
+		napi_enable(&fep->napi);
 		netif_device_attach(ndev);
 		phy_start(fep->phy_dev);
 	}
-- 
1.8.3.1

[PATCH B 05/10] net: fec: remove inappropriate calls around fec_restart()

[Russell King]

This is the second stage to "move calls to quiesce/resume packet
processing out of fec_restart()", where we remove calls which are not
appropriate to the call site.

In the majority of cases, there is no need to detach and reattach the
interface as we are holding the queue xmit lock across the reset.  The
exception to that is in fec_resume(), where we are already detached by
the suspend function.  Here, we can remove the call to detach the
interface.

We also do not need to stop the transmit queue.  Holding the xmit lock
is enough to ensure that the transmit packet processing is not running
while we perform our task.  However, since fec_restart() always cleans
the rings, we call netif_wake_queue() (or netif_device_attach() in the
case of resume) just before dropping the xmit lock.  This prevents the
watchdog firing.

Lastly, always call napi_enable() after the device has been reattached
in the resume path so that we know that the transmit packet processing
is already in an enabled state, so we don't call netif_wake_queue()
while detached.

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 | 26 ++++++--------------------
 1 file changed, 6 insertions(+), 20 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index b71b7491f38f..25a9f7fb30da 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1058,15 +1058,12 @@ static void fec_enet_work(struct work_struct *work)
 		fep->delay_work.timeout = false;
 		rtnl_lock();
 		if (netif_device_present(ndev) || netif_running(ndev)) {
-			netif_device_detach(ndev);
 			napi_disable(&fep->napi);
-			netif_tx_disable(ndev);
 			netif_tx_lock_bh(ndev);
 			fec_restart(ndev, fep->full_duplex);
-			netif_tx_unlock_bh(ndev);
 			netif_wake_queue(ndev);
+			netif_tx_unlock_bh(ndev);
 			napi_enable(&fep->napi);
-			netif_device_attach(ndev);
 		}
 		rtnl_unlock();
 	}
@@ -1524,15 +1521,12 @@ static void fec_enet_adjust_link(struct net_device *ndev)
 
 		/* if any of the above changed restart the FEC */
 		if (status_change) {
-			netif_device_detach(ndev);
 			napi_disable(&fep->napi);
-			netif_tx_disable(ndev);
 			netif_tx_lock_bh(ndev);
 			fec_restart(ndev, phy_dev->duplex);
-			netif_tx_unlock_bh(ndev);
 			netif_wake_queue(ndev);
+			netif_tx_unlock_bh(ndev);
 			napi_enable(&fep->napi);
-			netif_device_attach(ndev);
 		}
 	} else {
 		if (fep->link) {
@@ -1919,15 +1913,12 @@ static int fec_enet_set_pauseparam(struct net_device *ndev,
 		phy_start_aneg(fep->phy_dev);
 	}
 	if (netif_running(ndev)) {
-		netif_device_detach(ndev);
 		napi_disable(&fep->napi);
-		netif_tx_disable(ndev);
 		netif_tx_lock_bh(ndev);
 		fec_restart(ndev, fep->full_duplex);
-		netif_tx_unlock_bh(ndev);
 		netif_wake_queue(ndev);
+		netif_tx_unlock_bh(ndev);
 		napi_enable(&fep->napi);
-		netif_device_attach(ndev);
 	}
 
 	return 0;
@@ -2371,15 +2362,12 @@ static int fec_set_features(struct net_device *netdev,
 
 		if (netif_running(netdev)) {
 			fec_stop(netdev);
-			netif_device_detach(netdev);
 			napi_disable(&fep->napi);
-			netif_tx_disable(netdev);
 			netif_tx_lock_bh(netdev);
 			fec_restart(netdev, fep->phy_dev->duplex);
-			netif_tx_unlock_bh(netdev);
 			netif_wake_queue(netdev);
+			netif_tx_unlock_bh(netdev);
 			napi_enable(&fep->napi);
-			netif_device_attach(netdev);
 		}
 	}
 
@@ -2747,15 +2735,13 @@ fec_resume(struct device *dev)
 
 	rtnl_lock();
 	if (netif_running(ndev)) {
-		netif_device_detach(ndev);
 		napi_disable(&fep->napi);
-		netif_tx_disable(ndev);
 		netif_tx_lock_bh(ndev);
 		fec_restart(ndev, fep->full_duplex);
+		netif_device_attach(ndev);
 		netif_tx_unlock_bh(ndev);
-		netif_wake_queue(ndev);
-		napi_enable(&fep->napi);
 		netif_device_attach(ndev);
+		napi_enable(&fep->napi);
 		phy_start(fep->phy_dev);
 	}
 	rtnl_unlock();
-- 
1.8.3.1

[PATCH B 06/10] net: fec: quiesce packet processing before stopping device in fec_suspend()

[Russell King]

fec_suspend() calls fec_stop() to stop the transmit ring while the
transmit packet processing is still active.  This can lead to the
transmit queue being restarted by an intervening packet queued for
transmission, or by the tx quirk timer expiring.

Fix this by disabling NAPI first, which will ensure that the NAPI
handlers are not running.  Then, take the transmit lock before
detaching the netif device.  This ensures that there are no races
with the transmit path - and also ensures that the watchdog won't
fire.

We can then safely stop the ethernet device itself, knowing that the
rest of the driver is safely shut down.

On resume, we bring the device back up in reverse order - we restart
the device, reattach the device (under the tx lock), and then enable
the NAPI handlers.

We also need to adjust the close function to cope with this new
sequence, so that it's possible to cleanly close down the driver
after the hardware fails to resume (eg, due to the regulator_enable()
or pinctrl calls in the resume path returning an error.)

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 | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 25a9f7fb30da..fc9f6f465e7a 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -2211,10 +2211,11 @@ fec_enet_close(struct net_device *ndev)
 
 	phy_stop(fep->phy_dev);
 
-	napi_disable(&fep->napi);
-	netif_tx_disable(ndev);
-	if (netif_device_present(ndev))
+	if (netif_device_present(ndev)) {
+		napi_disable(&fep->napi);
+		netif_tx_disable(ndev);
 		fec_stop(ndev);
+	}
 
 	phy_disconnect(fep->phy_dev);
 	fep->phy_dev = NULL;
@@ -2701,8 +2702,11 @@ fec_suspend(struct device *dev)
 	rtnl_lock();
 	if (netif_running(ndev)) {
 		phy_stop(fep->phy_dev);
-		fec_stop(ndev);
+		napi_disable(&fep->napi);
+		netif_tx_lock_bh(ndev);
 		netif_device_detach(ndev);
+		netif_tx_unlock_bh(ndev);
+		fec_stop(ndev);
 	}
 	rtnl_unlock();
 
@@ -2735,12 +2739,10 @@ fec_resume(struct device *dev)
 
 	rtnl_lock();
 	if (netif_running(ndev)) {
-		napi_disable(&fep->napi);
-		netif_tx_lock_bh(ndev);
 		fec_restart(ndev, fep->full_duplex);
+		netif_tx_lock_bh(ndev);
 		netif_device_attach(ndev);
 		netif_tx_unlock_bh(ndev);
-		netif_device_attach(ndev);
 		napi_enable(&fep->napi);
 		phy_start(fep->phy_dev);
 	}
-- 
1.8.3.1

[PATCH B 07/10] net: fec: quiesce packet processing before stopping device in fec_set_features()

[Russell King]

fec_set_features() calls fec_stop() to stop the transmit ring while the
transmit queue is still active.  This can lead to the transmit ring
being restarted by an intervening packet queued for transmission, or
by the tx quirk timer expiring.

Fix this by disabling NAPI (which ensures that the NAPI handlers are
not running), and then take the transmit lock while we stop and
restart the adapter (which prevents new packets being queued).

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 fc9f6f465e7a..2945cf6e65cf 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -2362,9 +2362,9 @@ static int fec_set_features(struct net_device *netdev,
 			fep->csum_flags &= ~FLAG_RX_CSUM_ENABLED;
 
 		if (netif_running(netdev)) {
-			fec_stop(netdev);
 			napi_disable(&fep->napi);
 			netif_tx_lock_bh(netdev);
+			fec_stop(netdev);
 			fec_restart(netdev, fep->phy_dev->duplex);
 			netif_wake_queue(netdev);
 			netif_tx_unlock_bh(netdev);
-- 
1.8.3.1

[PATCH B 08/10] net: fec: quiesce packet processing before changing features

[Russell King]

Changing the features (receive checksumming) requires the hardware to be
reprogrammed, and also changes the checks in the receive packet
processing.

The current implementation has a race - fec_set_features() changes the
flags which alter the receive packet processing while the adapter is
active, and potentially receiving frames.  Only after we've modified
the software flag do we shutdown and reconfigure the hardware.

This can lead to packets being received and marked with a valid checksum
(via CHECKSUM_UNNECESSARY) when the hardware checksum validation has not
yet been enabled.

We must quiesce the device, then change the software configuration for
this feature, and then resume the device if it was previously running.

The resulting code structure also allows us to add other configuration
features in this path without having to quiesce and resume the network
interface and device.

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 | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 2945cf6e65cf..124d3c5f8046 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -2346,12 +2346,21 @@ static void fec_poll_controller(struct net_device *dev)
 }
 #endif
 
+#define FEATURES_NEED_QUIESCE NETIF_F_RXCSUM
+
 static int fec_set_features(struct net_device *netdev,
 	netdev_features_t features)
 {
 	struct fec_enet_private *fep = netdev_priv(netdev);
 	netdev_features_t changed = features ^ netdev->features;
 
+	/* Quiesce the device if necessary */
+	if (netif_running(netdev) && changed & FEATURES_NEED_QUIESCE) {
+		napi_disable(&fep->napi);
+		netif_tx_lock_bh(netdev);
+		fec_stop(netdev);
+	}
+
 	netdev->features = features;
 
 	/* Receive checksum has been changed */
@@ -2360,16 +2369,14 @@ static int fec_set_features(struct net_device *netdev,
 			fep->csum_flags |= FLAG_RX_CSUM_ENABLED;
 		else
 			fep->csum_flags &= ~FLAG_RX_CSUM_ENABLED;
+	}
 
-		if (netif_running(netdev)) {
-			napi_disable(&fep->napi);
-			netif_tx_lock_bh(netdev);
-			fec_stop(netdev);
-			fec_restart(netdev, fep->phy_dev->duplex);
-			netif_wake_queue(netdev);
-			netif_tx_unlock_bh(netdev);
-			napi_enable(&fep->napi);
-		}
+	/* Resume the device after updates */
+	if (netif_running(netdev) && changed & FEATURES_NEED_QUIESCE) {
+		fec_restart(netdev, fep->phy_dev->duplex);
+		netif_wake_queue(netdev);
+		netif_tx_unlock_bh(netdev);
+		napi_enable(&fep->napi);
 	}
 
 	return 0;
-- 
1.8.3.1

[PATCH B 09/10] net: fec: quiesce packet processing when taking link down in fec_enet_adjust_link()

[Russell King]

When the link goes down, the adjust_link method will be called, but
there is no synchronisation to ensure that we won't be processing some
last remaining packets via the NAPI handlers while performing a reset of
the device.

Add the necessary synchronisation to ensure that packet processing
is complete before we stop and reset the FEC.

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 124d3c5f8046..0186fec1f7f9 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1530,7 +1530,11 @@ static void fec_enet_adjust_link(struct net_device *ndev)
 		}
 	} else {
 		if (fep->link) {
+			napi_disable(&fep->napi);
+			netif_tx_lock_bh(ndev);
 			fec_stop(ndev);
+			netif_tx_unlock_bh(ndev);
+			napi_enable(&fep->napi);
 			fep->link = phy_dev->link;
 			status_change = 1;
 		}
-- 
1.8.3.1

[PATCH B 10/10] net: fec: clean up duplex mode handling

[Russell King]

Many places call fec_restart() with the second parameter being some kind
of previously saved duplex value, but only two places call it with some
other setting.  This is at odds with how the other link settings are
handled, and used to be racy before the rtnl locks were added to
fec_restart()'s various call paths.

Clean this up so all link capabilities are handled in the same way -
saved into the fec_enet_private structure, and then fec_restart() acts
on those settings.

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 | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 0186fec1f7f9..9d82d915b06d 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -824,7 +824,7 @@ static void fec_enet_bd_init(struct net_device *dev)
  * packet processing for this device must be stopped before this call.
  */
 static void
-fec_restart(struct net_device *ndev, int duplex)
+fec_restart(struct net_device *ndev)
 {
 	struct fec_enet_private *fep = netdev_priv(ndev);
 	const struct platform_device_id *id_entry =
@@ -875,7 +875,7 @@ fec_restart(struct net_device *ndev, int duplex)
 	}
 
 	/* Enable MII mode */
-	if (duplex) {
+	if (fep->full_duplex == DUPLEX_FULL) {
 		/* FD enable */
 		writel(0x04, fep->hwp + FEC_X_CNTRL);
 	} else {
@@ -884,8 +884,6 @@ fec_restart(struct net_device *ndev, int duplex)
 		writel(0x0, fep->hwp + FEC_X_CNTRL);
 	}
 
-	fep->full_duplex = duplex;
-
 	/* Set MII speed */
 	writel(fep->phy_speed, fep->hwp + FEC_MII_SPEED);
 
@@ -1060,7 +1058,7 @@ static void fec_enet_work(struct work_struct *work)
 		if (netif_device_present(ndev) || netif_running(ndev)) {
 			napi_disable(&fep->napi);
 			netif_tx_lock_bh(ndev);
-			fec_restart(ndev, fep->full_duplex);
+			fec_restart(ndev);
 			netif_wake_queue(ndev);
 			netif_tx_unlock_bh(ndev);
 			napi_enable(&fep->napi);
@@ -1511,8 +1509,10 @@ static void fec_enet_adjust_link(struct net_device *ndev)
 			status_change = 1;
 		}
 
-		if (fep->full_duplex != phy_dev->duplex)
+		if (fep->full_duplex != phy_dev->duplex) {
+			fep->full_duplex = phy_dev->duplex;
 			status_change = 1;
+		}
 
 		if (phy_dev->speed != fep->speed) {
 			fep->speed = phy_dev->speed;
@@ -1523,7 +1523,7 @@ static void fec_enet_adjust_link(struct net_device *ndev)
 		if (status_change) {
 			napi_disable(&fep->napi);
 			netif_tx_lock_bh(ndev);
-			fec_restart(ndev, phy_dev->duplex);
+			fec_restart(ndev);
 			netif_wake_queue(ndev);
 			netif_tx_unlock_bh(ndev);
 			napi_enable(&fep->napi);
@@ -1919,7 +1919,7 @@ static int fec_enet_set_pauseparam(struct net_device *ndev,
 	if (netif_running(ndev)) {
 		napi_disable(&fep->napi);
 		netif_tx_lock_bh(ndev);
-		fec_restart(ndev, fep->full_duplex);
+		fec_restart(ndev);
 		netif_wake_queue(ndev);
 		netif_tx_unlock_bh(ndev);
 		napi_enable(&fep->napi);
@@ -2201,7 +2201,7 @@ fec_enet_open(struct net_device *ndev)
 		return ret;
 	}
 
-	fec_restart(ndev, fep->full_duplex);
+	fec_restart(ndev);
 	napi_enable(&fep->napi);
 	phy_start(fep->phy_dev);
 	netif_start_queue(ndev);
@@ -2377,7 +2377,7 @@ static int fec_set_features(struct net_device *netdev,
 
 	/* Resume the device after updates */
 	if (netif_running(netdev) && changed & FEATURES_NEED_QUIESCE) {
-		fec_restart(netdev, fep->phy_dev->duplex);
+		fec_restart(netdev);
 		netif_wake_queue(netdev);
 		netif_tx_unlock_bh(netdev);
 		napi_enable(&fep->napi);
@@ -2481,7 +2481,7 @@ static int fec_enet_init(struct net_device *ndev)
 
 	ndev->hw_features = ndev->features;
 
-	fec_restart(ndev, 0);
+	fec_restart(ndev);
 
 	return 0;
 }
@@ -2750,7 +2750,7 @@ fec_resume(struct device *dev)
 
 	rtnl_lock();
 	if (netif_running(ndev)) {
-		fec_restart(ndev, fep->full_duplex);
+		fec_restart(ndev);
 		netif_tx_lock_bh(ndev);
 		netif_device_attach(ndev);
 		netif_tx_unlock_bh(ndev);
-- 
1.8.3.1

[PATCH B 00/10] Freescale ethernet driver updates (part 2)

[David Miller]

From: Russell King - ARM Linux <linux@arm.linux.org.uk>
Date: Tue, 8 Jul 2014 12:39:11 +0100

> Here's the second batch of patches for the Freescale FEC ethernet driver,
> based upon the previous set of patches.  One further set of 7 patches
> remains.

Series applied, thanks Russell.