Implement much easier and more lightweight locking for
the periodic work. This also removes the last big busywait
loop and replaces it by a sleeping loop.
This patch for b43legacy is patterned aftar the same patch
for b43 by Michael Buesch <mb@xxxxxxxxx>.
Signed-off-by: Larry Finger <larry.finger@xxxxxxxxxxxx>
---
drivers/net/wireless/b43legacy/main.c | 88 +++++++++++-----------------------
1 file changed, 30 insertions(+), 58 deletions(-)
Index: wireless-2.6/drivers/net/wireless/b43legacy/main.c
===================================================================
--- wireless-2.6.orig/drivers/net/wireless/b43legacy/main.c
+++ wireless-2.6/drivers/net/wireless/b43legacy/main.c
@@ -1797,6 +1797,7 @@ void b43legacy_mac_enable(struct b43lega
{
dev->mac_suspended--;
B43legacy_WARN_ON(dev->mac_suspended < 0);
+ B43legacy_WARN_ON(irqs_disabled());
if (dev->mac_suspended == 0) {
b43legacy_write32(dev, B43legacy_MMIO_STATUS_BITFIELD,
b43legacy_read32(dev,
@@ -1808,6 +1809,11 @@ void b43legacy_mac_enable(struct b43lega
b43legacy_read32(dev, B43legacy_MMIO_STATUS_BITFIELD);
b43legacy_read32(dev, B43legacy_MMIO_GEN_IRQ_REASON);
b43legacy_power_saving_ctl_bits(dev, -1, -1);
+
+ /* Re-enable IRQs. */
+ spin_lock_irq(&dev->wl->irq_lock);
+ b43legacy_interrupt_enable(dev, dev->irq_savedstate);
+ spin_unlock_irq(&dev->wl->irq_lock);
}
}
@@ -1817,20 +1823,31 @@ void b43legacy_mac_suspend(struct b43leg
int i;
u32 tmp;
+ might_sleep();
+ B43legacy_WARN_ON(irqs_disabled());
B43legacy_WARN_ON(dev->mac_suspended < 0);
+
if (dev->mac_suspended == 0) {
+ /* Mask IRQs before suspending MAC. Otherwise
+ * the MAC stays busy and won't suspend. */
+ spin_lock_irq(&dev->wl->irq_lock);
+ tmp = b43legacy_interrupt_disable(dev, B43legacy_IRQ_ALL);
+ spin_unlock_irq(&dev->wl->irq_lock);
+ b43legacy_synchronize_irq(dev);
+ dev->irq_savedstate = tmp;
+
b43legacy_power_saving_ctl_bits(dev, -1, 1);
b43legacy_write32(dev, B43legacy_MMIO_STATUS_BITFIELD,
b43legacy_read32(dev,
B43legacy_MMIO_STATUS_BITFIELD)
& ~B43legacy_SBF_MAC_ENABLED);
b43legacy_read32(dev, B43legacy_MMIO_GEN_IRQ_REASON);
- for (i = 10000; i; i--) {
+ for (i = 40; i; i--) {
tmp = b43legacy_read32(dev,
B43legacy_MMIO_GEN_IRQ_REASON);
if (tmp & B43legacy_IRQ_MAC_SUSPENDED)
goto out;
- udelay(1);
+ msleep(1);
}
b43legacyerr(dev->wl, "MAC suspend failed\n");
}
@@ -2145,81 +2162,36 @@ static void do_periodic_work(struct b43l
b43legacy_periodic_every15sec(dev);
}
-/* Estimate a "Badness" value based on the periodic work
- * state-machine state. "Badness" is worse (bigger), if the
- * periodic work will take longer.
+/* Periodic work locking policy:
+ * The whole periodic work handler is protected by
+ * wl->mutex. If another lock is needed somewhere in the
+ * pwork callchain, it's aquired in-place, where it's needed.
*/
-static int estimate_periodic_work_badness(unsigned int state)
-{
- int badness = 0;
-
- if (state % 8 == 0) /* every 120 sec */
- badness += 10;
- if (state % 4 == 0) /* every 60 sec */
- badness += 5;
- if (state % 2 == 0) /* every 30 sec */
- badness += 1;
-
-#define BADNESS_LIMIT 4
- return badness;
-}
-
static void b43legacy_periodic_work_handler(struct work_struct *work)
{
- struct b43legacy_wldev *dev =
- container_of(work, struct b43legacy_wldev,
- periodic_work.work);
- unsigned long flags;
+ struct b43legacy_wldev *dev = container_of(work, struct b43legacy_wldev,
+ periodic_work.work);
+ struct b43legacy_wl *wl = dev->wl;
unsigned long delay;
- u32 savedirqs = 0;
- int badness;
- mutex_lock(&dev->wl->mutex);
+ mutex_lock(&wl->mutex);
if (unlikely(b43legacy_status(dev) != B43legacy_STAT_STARTED))
goto out;
if (b43legacy_debug(dev, B43legacy_DBG_PWORK_STOP))
goto out_requeue;
- badness = estimate_periodic_work_badness(dev->periodic_state);
- if (badness > BADNESS_LIMIT) {
- spin_lock_irqsave(&dev->wl->irq_lock, flags);
- /* Suspend TX as we don't want to transmit packets while
- * we recalibrate the hardware. */
- b43legacy_tx_suspend(dev);
- savedirqs = b43legacy_interrupt_disable(dev,
- B43legacy_IRQ_ALL);
- /* Periodic work will take a long time, so we want it to
- * be preemtible and release the spinlock. */
- spin_unlock_irqrestore(&dev->wl->irq_lock, flags);
- b43legacy_synchronize_irq(dev);
-
- do_periodic_work(dev);
+ do_periodic_work(dev);
- spin_lock_irqsave(&dev->wl->irq_lock, flags);
- b43legacy_interrupt_enable(dev, savedirqs);
- b43legacy_tx_resume(dev);
- mmiowb();
- spin_unlock_irqrestore(&dev->wl->irq_lock, flags);
- } else {
- /* Take the global driver lock. This will lock any operation. */
- spin_lock_irqsave(&dev->wl->irq_lock, flags);
-
- do_periodic_work(dev);
-
- mmiowb();
- spin_unlock_irqrestore(&dev->wl->irq_lock, flags);
- }
dev->periodic_state++;
out_requeue:
if (b43legacy_debug(dev, B43legacy_DBG_PWORK_FAST))
delay = msecs_to_jiffies(50);
else
delay = round_jiffies(HZ * 15);
- queue_delayed_work(dev->wl->hw->workqueue,
- &dev->periodic_work, delay);
+ queue_delayed_work(wl->hw->workqueue, &dev->periodic_work, delay);
out:
- mutex_unlock(&dev->wl->mutex);
+ mutex_unlock(&wl->mutex);
}
static void b43legacy_periodic_tasks_setup(struct b43legacy_wldev *dev)
-
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