[PATCH net-next v3 4/8] net: ethernet: fs_enet: only protect the .restart() call in .adjust_link

[Maxime Chevallier]

When .adjust_link() gets called, it runs in thread context, with the
phydev->lock held. We only need to protect the fep->fecp/fccp/sccp
register that are accessed within the .restart() function from
concurrent access from the interrupts.

These registers are being protected by the fep->lock spinlock, so we can
move the spinlock protection around the .restart() call instead of the
entire adjust_link() call. By doing so, we can simplify further the
.adjust_link() callback and avoid the intermediate helper.

Suggested-by: Andrew Lunn <and...@lunn.ch>
Signed-off-by: Maxime Chevallier <maxime.chevall...@bootlin.com>
---
 .../ethernet/freescale/fs_enet/fs_enet-main.c  | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c 
b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c
index caca81b3ccb6..b320e55dcb81 100644
--- a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c
+++ b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c
@@ -607,10 +607,11 @@ static void fs_timeout(struct net_device *dev, unsigned 
int txqueue)
 }
 
 /* generic link-change handler - should be sufficient for most cases */
-static void generic_adjust_link(struct  net_device *dev)
+static void fs_adjust_link(struct  net_device *dev)
 {
        struct fs_enet_private *fep = netdev_priv(dev);
        struct phy_device *phydev = dev->phydev;
+       unsigned long flags;
        int new_state = 0;
 
        if (phydev->link) {
@@ -630,8 +631,11 @@ static void generic_adjust_link(struct  net_device *dev)
                        fep->oldlink = 1;
                }
 
-               if (new_state)
+               if (new_state) {
+                       spin_lock_irqsave(&fep->lock, flags);
                        fep->ops->restart(dev);
+                       spin_unlock_irqrestore(&fep->lock, flags);
+               }
        } else if (fep->oldlink) {
                new_state = 1;
                fep->oldlink = 0;
@@ -643,16 +647,6 @@ static void generic_adjust_link(struct  net_device *dev)
                phy_print_status(phydev);
 }
 
-static void fs_adjust_link(struct net_device *dev)
-{
-       struct fs_enet_private *fep = netdev_priv(dev);
-       unsigned long flags;
-
-       spin_lock_irqsave(&fep->lock, flags);
-       generic_adjust_link(dev);
-       spin_unlock_irqrestore(&fep->lock, flags);
-}
-
 static int fs_init_phy(struct net_device *dev)
 {
        struct fs_enet_private *fep = netdev_priv(dev);
-- 
2.46.0