From: Ben Hutchings <ben@decadent.org.uk>
Date: Mon, 30 Aug 2010 14:15:33 +0000 (+0000)
Subject: 3c59x: Remove incorrect locking; correct documented lock hierarchy
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=24cd804d1dc60a74c53da983094df3516500c276;p=openwrt%2Fstaging%2Fblogic.git

3c59x: Remove incorrect locking; correct documented lock hierarchy

vortex_ioctl() was grabbing vortex_private::lock around its call to
generic_mii_ioctl().  This is no longer necessary since there are more
specific locks which the mdio_{read,write}() functions will obtain.
Worse, those functions do not save and restore IRQ flags when locking
the MII state, so interrupts will be enabled when generic_mii_ioctl()
returns.

Since there is currently no need for any function to call
mdio_{read,write}() while holding another spinlock, do not change them
to save and restore IRQ flags but remove the specification of ordering
between vortex_private::lock and vortex_private::mii_lock.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/3c59x.c b/drivers/net/3c59x.c
index c685a55fc2f4..a045559c81cf 100644
--- a/drivers/net/3c59x.c
+++ b/drivers/net/3c59x.c
@@ -647,7 +647,7 @@ struct vortex_private {
 	u16 io_size;						/* Size of PCI region (for release_region) */
 
 	/* Serialises access to hardware other than MII and variables below.
-	 * The lock hierarchy is rtnl_lock > lock > mii_lock > window_lock. */
+	 * The lock hierarchy is rtnl_lock > {lock, mii_lock} > window_lock. */
 	spinlock_t lock;
 
 	spinlock_t mii_lock;		/* Serialises access to MII */
@@ -2984,7 +2984,6 @@ static int vortex_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
 {
 	int err;
 	struct vortex_private *vp = netdev_priv(dev);
-	unsigned long flags;
 	pci_power_t state = 0;
 
 	if(VORTEX_PCI(vp))
@@ -2994,9 +2993,7 @@ static int vortex_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
 
 	if(state != 0)
 		pci_set_power_state(VORTEX_PCI(vp), PCI_D0);
-	spin_lock_irqsave(&vp->lock, flags);
 	err = generic_mii_ioctl(&vp->mii, if_mii(rq), cmd, NULL);
-	spin_unlock_irqrestore(&vp->lock, flags);
 	if(state != 0)
 		pci_set_power_state(VORTEX_PCI(vp), state);