[PATCH] PHYLIB: Spinlock fixes for softirqs

Maciej W. Rozycki
2007-09-18T14:58:32Z

Use spin_lock_bh()/spin_unlock_bh() for the phydev lock throughout as it
is used in phy_timer() that is called as a softirq and all the other
operations may happen in the user context.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
---
There has been a change recently that did such a conversion for some of
the operations on the lock, but some have been left intact. Many of them,
perhaps all, may be called in the user context and I was able to trigger
recursive spinlock acquisition indeed, so I think for the sake of
long-term maintenance it is best to convert them all, even if
unnecessarily for one or two -- better safe than sorry.

Perhaps one in phy_timer() could actually be skipped as only called as a
softirq -- I can send an update if that sounds like a good idea.

Checked with checkpatch.pl and at the runtime.

Please apply,

Maciej

patch-netdev-2.6.23-rc6-20070913-phy-spinlock-8
diff -up --recursive --new-file linux-netdev-2.6.23-rc6-20070913.macro/drivers/net/phy/phy.c linux-netdev-2.6.23-rc6-20070913/drivers/net/phy/phy.c
--- linux-netdev-2.6.23-rc6-20070913.macro/drivers/net/phy/phy.c 2007-09-13 17:27:52.000000000 +0000
+++ linux-netdev-2.6.23-rc6-20070913/drivers/net/phy/phy.c 2007-09-16 17:26:02.000000000 +0000
@@ -423,7 +423,7 @@ int phy_start_aneg(struct phy_device *ph
{
int err;

- spin_lock(&phydev->lock);
+ spin_lock_bh(&phydev->lock);

if (AUTONEG_DISABLE == phydev->autoneg)
phy_sanitize_settings(phydev);
@@ -444,7 +444,7 @@ int phy_start_aneg(struct phy_device *ph
}

out_unlock:
- spin_unlock(&phydev->lock);
+ spin_unlock_bh(&phydev->lock);
return err;
}
EXPORT_SYMBOL(phy_start_aneg);
@@ -489,10 +489,10 @@ void phy_stop_machine(struct phy_device
{
del_timer_sync(&phydev->phy_timer);

- spin_lock(&phydev->lock);
+ spin_lock_bh(&phydev->lock);
if (phydev->state > PHY_UP)
phydev->state = PHY_UP;
- spin_unlock(&phydev->lock);
+ spin_unlock_bh(&phydev->lock);

phydev->adjust_state = NULL;
}
@@ -536,9 +536,9 @@ static void phy_force_reduction(struct p
*/
void phy_error(struct phy_device *phydev)
{
- spin_lock(&phydev->lock);
+ spin_lock_bh(&phydev->lock);
phydev->state = PHY_HALTED;
- spin_unlock(&phydev->lock);
+ spin_unlock_bh(&phydev->lock);
}

/**
@@ -689,10 +689,10 @@ static void phy_change(struct work_struc
if (err)
goto phy_err;

- spin_lock(&phydev->lock);
+ spin_lock_bh(&phydev->lock);
if ((PHY_RUNNING == phydev->state) || (PHY_NOLINK == phydev->state))
phydev->state = PHY_CHANGELINK;
- spin_unlock(&phydev->lock);
+ spin_unlock_bh(&phydev->lock);

enable_irq(phydev->irq);

@@ -717,7 +717,7 @@ phy_err:
*/
void phy_stop(struct phy_device *phydev)
{
- spin_lock(&phydev->lock);
+ spin_lock_bh(&phydev->lock);

if (PHY_HALTED == phydev->state)
goto out_unlock;
@@ -733,7 +733,7 @@ void phy_stop(struct phy_device *phydev)
}

out_unlock:
- spin_unlock(&phydev->lock);
+ spin_unlock_bh(&phydev->lock);

/*
* Cannot call flush_scheduled_work() here as desired because
@@ -781,7 +781,7 @@ static void phy_timer(unsigned long data
int needs_aneg = 0;
int err = 0;

- spin_lock(&phydev->lock);
+ spin_lock_bh(&phydev->lock);

if (phydev->adjust_state)
phydev->adjust_state(phydev->attached_dev);
@@ -947,7 +947,7 @@ static void phy_timer(unsigned long data
break;
}

- spin_unlock(&phydev->lock);
+ spin_unlock_bh(&phydev->lock);

if (needs_aneg)
err = phy_start_aneg(phydev);
diff -up --recursive --new-file linux-netdev-2.6.23-rc6-20070913.macro/drivers/net/phy/phy_device.c linux-netdev-2.6.23-rc6-20070913/drivers/net/phy/phy_device.c
--- linux-netdev-2.6.23-rc6-20070913.macro/drivers/net/phy/phy_device.c 2007-09-13 17:27:52.000000000 +0000
+++ linux-netdev-2.6.23-rc6-20070913/drivers/net/phy/phy_device.c 2007-09-16 17:27:48.000000000 +0000
@@ -670,9 +670,9 @@ static int phy_remove(struct device *dev

phydev = to_phy_device(dev);

- spin_lock(&phydev->lock);
+ spin_lock_bh(&phydev->lock);
phydev->state = PHY_DOWN;
- spin_unlock(&phydev->lock);
+ spin_unlock_bh(&phydev->lock);

if (phydev->drv->remove)
phydev->drv->remove(phydev);