3.16.61-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Vladimir Zapolskiy <vladimir_zapols...@mentor.com>

commit 5cb3f52a11e18628fc4bee76dd14b1f0b76349de upstream.

The change fixes sleep in atomic context bug, which is encountered
every time when link settings are changed by ethtool.

Since commit 35b5f6b1a82b ("PHYLIB: Locking fixes for PHY I/O
potentially sleeping") phy_start_aneg() function utilizes a mutex
to serialize changes to phy state, however that helper function is
called in atomic context under a grabbed spinlock, because
phy_start_aneg() is called by phy_ethtool_ksettings_set() and by
replaced phy_ethtool_sset() helpers from phylib.

Now duplex mode setting is enforced in sh_eth_adjust_link() only,
also now RX/TX is disabled when link is put down or modifications
to E-MAC registers ECMR and GECMR are expected for both cases of
checked and ignored link status pin state from E-MAC interrupt handler.

For reference the change is a partial rework of commit 1e1b812bbe10
("sh_eth: fix handling of no LINK signal").

Fixes: dc19e4e5e02f ("sh: sh_eth: Add support ethtool")
Signed-off-by: Vladimir Zapolskiy <vladimir_zapols...@mentor.com>
Reviewed-by: Sergei Shtylyov <sergei.shtyl...@cogentembedded.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
[bwh: Backported to 3.16:
 - Keep using phy_ethtool_sset()
 - Adjust context]
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -1727,8 +1727,15 @@ static void sh_eth_adjust_link(struct ne
 {
        struct sh_eth_private *mdp = netdev_priv(ndev);
        struct phy_device *phydev = mdp->phydev;
+       unsigned long flags;
        int new_state = 0;
 
+       spin_lock_irqsave(&mdp->lock, flags);
+
+       /* Disable TX and RX right over here, if E-MAC change is ignored */
+       if (mdp->cd->no_psr || mdp->no_ether_link)
+               sh_eth_rcv_snd_disable(ndev);
+
        if (phydev->link) {
                if (phydev->duplex != mdp->duplex) {
                        new_state = 1;
@@ -1749,18 +1756,21 @@ static void sh_eth_adjust_link(struct ne
                                     ECMR);
                        new_state = 1;
                        mdp->link = phydev->link;
-                       if (mdp->cd->no_psr || mdp->no_ether_link)
-                               sh_eth_rcv_snd_enable(ndev);
                }
        } else if (mdp->link) {
                new_state = 1;
                mdp->link = 0;
                mdp->speed = 0;
                mdp->duplex = -1;
-               if (mdp->cd->no_psr || mdp->no_ether_link)
-                       sh_eth_rcv_snd_disable(ndev);
        }
 
+       /* Enable TX and RX right over here, if E-MAC change is ignored */
+       if ((mdp->cd->no_psr || mdp->no_ether_link) && phydev->link)
+               sh_eth_rcv_snd_enable(ndev);
+
+       mmiowb();
+       spin_unlock_irqrestore(&mdp->lock, flags);
+
        if (new_state && netif_msg_link(mdp))
                phy_print_status(phydev);
 }
@@ -1843,35 +1853,8 @@ static int sh_eth_set_settings(struct ne
                               struct ethtool_cmd *ecmd)
 {
        struct sh_eth_private *mdp = netdev_priv(ndev);
-       unsigned long flags;
-       int ret;
-
-       spin_lock_irqsave(&mdp->lock, flags);
 
-       /* disable tx and rx */
-       sh_eth_rcv_snd_disable(ndev);
-
-       ret = phy_ethtool_sset(mdp->phydev, ecmd);
-       if (ret)
-               goto error_exit;
-
-       if (ecmd->duplex == DUPLEX_FULL)
-               mdp->duplex = 1;
-       else
-               mdp->duplex = 0;
-
-       if (mdp->cd->set_duplex)
-               mdp->cd->set_duplex(ndev);
-
-error_exit:
-       mdelay(1);
-
-       /* enable tx and rx */
-       sh_eth_rcv_snd_enable(ndev);
-
-       spin_unlock_irqrestore(&mdp->lock, flags);
-
-       return ret;
+       return phy_ethtool_sset(mdp->phydev, ecmd);
 }
 
 static int sh_eth_nway_reset(struct net_device *ndev)

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