[PATCH 1/2] gianfar: Deal with link state changes during GFAR_RESETTING dev state

[PATCH 1/2] gianfar: Deal with link state changes during GFAR_RESETTING dev state

[Thomas Graziadei]

From: Thomas Graziadei <thomas.graziadei@omicronenergy.com>

The link state is not correctly set in the case that the network driver
is reconfigured while the link state changes. The phy informs the gianfar
driver, but gfar_update_link_state just exits and therefore looses the
change event. The network driver remains in the old state until a new link
event is sent.

A trace log from a possible scenario at bootup, when the link state in the
network driver stays down even though the phy reports an up link. The test
sends a SIOCSHWTSTAMP ioctl at the right moment (which calls reset_gfar):
         ip-1196 [000]  5.389270: phy_start: state: READY -> UP
kworker/0:2-1195 [000]  5.389784: phy_start_aneg: state: UP -> AN
kworker/0:2-1195 [000]  5.389788: phy_state_machine: state: UP -> AN
kworker/0:2-1195 [000]  6.828064: adjust_link: eth0, link 0 -> 0
kworker/0:2-1195 [000]  6.828599: phy_state_machine: state: AN -> NOLINK
       test-1470 [000]  7.460422: reset_gfar: before locking GFAR_RESETTING
       test-1470 [000]  7.470806: phy_stop: state: NOLINK -> HALTED
       test-1470 [000]  7.478806: phy_start: state: HALTED -> RESUMING
kworker/0:2-1195 [000]  7.479478: adjust_link: eth0, link 0 -> 1
kworker/0:2-1195 [000]  7.479482: phy_state_machine: state: RESUMING -> RUNNING
       test-1470 [000]  7.479826: reset_gfar: after locking GFAR_RESETTING

To resolve the issue adjust_link is called after every GFAR_RESETTING lock
section. Adjust_link itself checks if anything has changed and updates the
link accordingly.

Signed-off-by: Thomas Graziadei <thomas.graziadei@omicronenergy.com>
---
 drivers/net/ethernet/freescale/gianfar.c         |  7 +++++++
 drivers/net/ethernet/freescale/gianfar_ethtool.c | 15 +++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index 957bfc2..b3b5c43 100644
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -2617,6 +2617,10 @@ static int gfar_change_mtu(struct net_device *dev, int new_mtu)
 
 	clear_bit_unlock(GFAR_RESETTING, &priv->state);
 
+	// catch maybe missed link state changes
+	if (dev->flags & IFF_UP)
+		adjust_link(dev);
+
 	return 0;
 }
 
@@ -2631,6 +2635,9 @@ void reset_gfar(struct net_device *ndev)
 	startup_gfar(ndev);
 
 	clear_bit_unlock(GFAR_RESETTING, &priv->state);
+
+	// catch maybe missed link state changes
+	adjust_link(ndev);
 }
 
 /* gfar_reset_task gets scheduled when a packet has not been
diff --git a/drivers/net/ethernet/freescale/gianfar_ethtool.c b/drivers/net/ethernet/freescale/gianfar_ethtool.c
index a93e019..065f05e 100644
--- a/drivers/net/ethernet/freescale/gianfar_ethtool.c
+++ b/drivers/net/ethernet/freescale/gianfar_ethtool.c
@@ -330,6 +330,7 @@ static int gfar_scoalesce(struct net_device *dev,
 			  struct ethtool_coalesce *cvals)
 {
 	struct gfar_private *priv = netdev_priv(dev);
+	struct phy_device *phydev = dev->phydev;
 	int i, err = 0;
 
 	if (!(priv->device_flags & FSL_GIANFAR_DEV_HAS_COALESCE))
@@ -408,6 +409,10 @@ static int gfar_scoalesce(struct net_device *dev,
 
 	clear_bit_unlock(GFAR_RESETTING, &priv->state);
 
+	// catch maybe missed link state changes
+	if (dev->flags & IFF_UP)
+		phydev->adjust_link(dev);
+
 	return err;
 }
 
@@ -445,6 +450,7 @@ static int gfar_sringparam(struct net_device *dev,
 			   struct ethtool_ringparam *rvals)
 {
 	struct gfar_private *priv = netdev_priv(dev);
+	struct phy_device *phydev = dev->phydev;
 	int err = 0, i;
 
 	if (rvals->rx_pending > GFAR_RX_MAX_RING_SIZE)
@@ -482,6 +488,10 @@ static int gfar_sringparam(struct net_device *dev,
 
 	clear_bit_unlock(GFAR_RESETTING, &priv->state);
 
+	// catch maybe missed link state changes
+	if (dev->flags & IFF_UP)
+		phydev->adjust_link(dev);
+
 	return err;
 }
 
@@ -569,6 +579,7 @@ int gfar_set_features(struct net_device *dev, netdev_features_t features)
 {
 	netdev_features_t changed = dev->features ^ features;
 	struct gfar_private *priv = netdev_priv(dev);
+	struct phy_device *phydev = dev->phydev;
 	int err = 0;
 
 	if (!(changed & (NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX |
@@ -590,6 +601,10 @@ int gfar_set_features(struct net_device *dev, netdev_features_t features)
 
 	clear_bit_unlock(GFAR_RESETTING, &priv->state);
 
+	// catch maybe missed link state changes
+	if (dev->flags & IFF_UP)
+		phydev->adjust_link(dev);
+
 	return err;
 }
 
-- 
2.7.4

[PATCH 2/2] gianfar: Use the same initial values as the phy layer

[Thomas Graziadei]

From: Thomas Graziadei <thomas.graziadei@omicronenergy.com>

The phy layer sets the link status initially to 1 to also support phyless
systems, therefore we set the gianfar drivers initial link status also to
1. This prevents the gfar_update_link_state() method to be called when the
driver and phy have just been initialized but no link state change was
detected yet.

Signed-off-by: Thomas Graziadei <thomas.graziadei@omicronenergy.com>
---
 drivers/net/ethernet/freescale/gianfar.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index b3b5c43..be0d23e 100644
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -1705,7 +1705,7 @@ static int gfar_restore(struct device *dev)
 
 	gfar_start(priv);
 
-	priv->oldlink = 0;
+	priv->oldlink = 1;
 	priv->oldspeed = 0;
 	priv->oldduplex = -1;
 
@@ -1791,7 +1791,7 @@ static int init_phy(struct net_device *dev)
 	phy_interface_t interface;
 	struct phy_device *phydev;
 
-	priv->oldlink = 0;
+	priv->oldlink = 1;
 	priv->oldspeed = 0;
 	priv->oldduplex = -1;
 
@@ -2212,7 +2212,7 @@ int startup_gfar(struct net_device *ndev)
 	gfar_start(priv);
 
 	/* force link state update after mac reset */
-	priv->oldlink = 0;
+	priv->oldlink = 1;
 	priv->oldspeed = 0;
 	priv->oldduplex = -1;
 
-- 
2.7.4

RE: [PATCH 1/2] gianfar: Deal with link state changes during GFAR_RESETTING dev state

[Claudiu Manoil]

>-----Original Message-----
>From: Thomas Graziadei [mailto:thomas.graziadei@omicronenergy.com]
>Sent: Monday, February 13, 2017 2:22 PM
>To: claudiu.manoil@freescale.com; netdev@vger.kernel.org; linux-
>kernel@vger.kernel.org
>Cc: Thomas Graziadei <thomas.graziadei@omicronenergy.com>
>Subject: [PATCH 1/2] gianfar: Deal with link state changes during GFAR_RESETTING
>dev state
>
>From: Thomas Graziadei <thomas.graziadei@omicronenergy.com>
>
>The link state is not correctly set in the case that the network driver
>is reconfigured while the link state changes. The phy informs the gianfar
>driver, but gfar_update_link_state just exits and therefore looses the
>change event. The network driver remains in the old state until a new link
>event is sent.
>
>A trace log from a possible scenario at bootup, when the link state in the
>network driver stays down even though the phy reports an up link. The test
>sends a SIOCSHWTSTAMP ioctl at the right moment (which calls reset_gfar):
>         ip-1196 [000]  5.389270: phy_start: state: READY -> UP
>kworker/0:2-1195 [000]  5.389784: phy_start_aneg: state: UP -> AN
>kworker/0:2-1195 [000]  5.389788: phy_state_machine: state: UP -> AN
>kworker/0:2-1195 [000]  6.828064: adjust_link: eth0, link 0 -> 0
>kworker/0:2-1195 [000]  6.828599: phy_state_machine: state: AN -> NOLINK
>       test-1470 [000]  7.460422: reset_gfar: before locking GFAR_RESETTING
>       test-1470 [000]  7.470806: phy_stop: state: NOLINK -> HALTED
>       test-1470 [000]  7.478806: phy_start: state: HALTED -> RESUMING
>kworker/0:2-1195 [000]  7.479478: adjust_link: eth0, link 0 -> 1
>kworker/0:2-1195 [000]  7.479482: phy_state_machine: state: RESUMING ->
>RUNNING
>       test-1470 [000]  7.479826: reset_gfar: after locking GFAR_RESETTING
>
>To resolve the issue adjust_link is called after every GFAR_RESETTING lock
>section. Adjust_link itself checks if anything has changed and updates the
>link accordingly.
>

Hi,
Interesting findings. I need more time to check the patches. Btw, we don't 
use "//" for comments on netdev.

Thanks,
Claudiu