b43: Use a threaded IRQ handler

Use a threaded IRQ handler to allow locking the mutex and
sleeping while executing an interrupt.
This removes usage of the irq_lock spinlock, but introduces
a new hardirq_lock, which is _only_ used for the PCI/SSB lowlevel
hard-irq handler. Sleeping busses (SDIO) will use mutex instead.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/b43/sysfs.c

@@ -94,7 +94,6 @@ static ssize_t b43_attr_interfmode_store(struct device *dev,
 					 const char *buf, size_t count)
 {
 	struct b43_wldev *wldev = dev_to_b43_wldev(dev);
-	unsigned long flags;
 	int err;
 	int mode;
 
@@ -120,7 +119,6 @@ static ssize_t b43_attr_interfmode_store(struct device *dev,
 	}
 
 	mutex_lock(&wldev->wl->mutex);
-	spin_lock_irqsave(&wldev->wl->irq_lock, flags);
 
 	if (wldev->phy.ops->interf_mitigation) {
 		err = wldev->phy.ops->interf_mitigation(wldev, mode);
@@ -132,7 +130,6 @@ static ssize_t b43_attr_interfmode_store(struct device *dev,
 		err = -ENOSYS;
 
 	mmiowb();
-	spin_unlock_irqrestore(&wldev->wl->irq_lock, flags);
 	mutex_unlock(&wldev->wl->mutex);
 
 	return err ? err : count;