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authorMichael Buesch <mb@bu3sch.de>2007-09-28 10:19:03 -0400
committerDavid S. Miller <davem@sunset.davemloft.net>2007-10-10 19:54:13 -0400
commit05b64b364822863974c0121359b01d7ba0f22205 (patch)
tree9f11ab39989780f93bdd953d798e070ada6ed069 /drivers/net/wireless/b43/main.c
parent42bb4cd5ae320dd46630533fecb91b940d4468e2 (diff)
[B43]: Rewrite pwork locking policy.
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. Signed-off-by: Michael Buesch <mb@bu3sch.de> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/wireless/b43/main.c')
-rw-r--r--drivers/net/wireless/b43/main.c88
1 files changed, 32 insertions, 56 deletions
diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index a603a154d496..6c80f2e2f4ee 100644
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -1976,6 +1976,7 @@ void b43_mac_enable(struct b43_wldev *dev)
1976{ 1976{
1977 dev->mac_suspended--; 1977 dev->mac_suspended--;
1978 B43_WARN_ON(dev->mac_suspended < 0); 1978 B43_WARN_ON(dev->mac_suspended < 0);
1979 B43_WARN_ON(irqs_disabled());
1979 if (dev->mac_suspended == 0) { 1980 if (dev->mac_suspended == 0) {
1980 b43_write32(dev, B43_MMIO_MACCTL, 1981 b43_write32(dev, B43_MMIO_MACCTL,
1981 b43_read32(dev, B43_MMIO_MACCTL) 1982 b43_read32(dev, B43_MMIO_MACCTL)
@@ -1986,6 +1987,11 @@ void b43_mac_enable(struct b43_wldev *dev)
1986 b43_read32(dev, B43_MMIO_MACCTL); 1987 b43_read32(dev, B43_MMIO_MACCTL);
1987 b43_read32(dev, B43_MMIO_GEN_IRQ_REASON); 1988 b43_read32(dev, B43_MMIO_GEN_IRQ_REASON);
1988 b43_power_saving_ctl_bits(dev, 0); 1989 b43_power_saving_ctl_bits(dev, 0);
1990
1991 /* Re-enable IRQs. */
1992 spin_lock_irq(&dev->wl->irq_lock);
1993 b43_interrupt_enable(dev, dev->irq_savedstate);
1994 spin_unlock_irq(&dev->wl->irq_lock);
1989 } 1995 }
1990} 1996}
1991 1997
@@ -1995,23 +2001,34 @@ void b43_mac_suspend(struct b43_wldev *dev)
1995 int i; 2001 int i;
1996 u32 tmp; 2002 u32 tmp;
1997 2003
2004 might_sleep();
2005 B43_WARN_ON(irqs_disabled());
1998 B43_WARN_ON(dev->mac_suspended < 0); 2006 B43_WARN_ON(dev->mac_suspended < 0);
2007
1999 if (dev->mac_suspended == 0) { 2008 if (dev->mac_suspended == 0) {
2009 /* Mask IRQs before suspending MAC. Otherwise
2010 * the MAC stays busy and won't suspend. */
2011 spin_lock_irq(&dev->wl->irq_lock);
2012 tmp = b43_interrupt_disable(dev, B43_IRQ_ALL);
2013 spin_unlock_irq(&dev->wl->irq_lock);
2014 b43_synchronize_irq(dev);
2015 dev->irq_savedstate = tmp;
2016
2000 b43_power_saving_ctl_bits(dev, B43_PS_AWAKE); 2017 b43_power_saving_ctl_bits(dev, B43_PS_AWAKE);
2001 b43_write32(dev, B43_MMIO_MACCTL, 2018 b43_write32(dev, B43_MMIO_MACCTL,
2002 b43_read32(dev, B43_MMIO_MACCTL) 2019 b43_read32(dev, B43_MMIO_MACCTL)
2003 & ~B43_MACCTL_ENABLED); 2020 & ~B43_MACCTL_ENABLED);
2004 /* force pci to flush the write */ 2021 /* force pci to flush the write */
2005 b43_read32(dev, B43_MMIO_MACCTL); 2022 b43_read32(dev, B43_MMIO_MACCTL);
2006 for (i = 10000; i; i--) { 2023 for (i = 40; i; i--) {
2007 tmp = b43_read32(dev, B43_MMIO_GEN_IRQ_REASON); 2024 tmp = b43_read32(dev, B43_MMIO_GEN_IRQ_REASON);
2008 if (tmp & B43_IRQ_MAC_SUSPENDED) 2025 if (tmp & B43_IRQ_MAC_SUSPENDED)
2009 goto out; 2026 goto out;
2010 udelay(1); 2027 msleep(1);
2011 } 2028 }
2012 b43err(dev->wl, "MAC suspend failed\n"); 2029 b43err(dev->wl, "MAC suspend failed\n");
2013 } 2030 }
2014 out: 2031out:
2015 dev->mac_suspended++; 2032 dev->mac_suspended++;
2016} 2033}
2017 2034
@@ -2349,77 +2366,36 @@ static void do_periodic_work(struct b43_wldev *dev)
2349 b43_periodic_every15sec(dev); 2366 b43_periodic_every15sec(dev);
2350} 2367}
2351 2368
2352/* Estimate a "Badness" value based on the periodic work 2369/* Periodic work locking policy:
2353 * state-machine state. "Badness" is worse (bigger), if the 2370 * The whole periodic work handler is protected by
2354 * periodic work will take longer. 2371 * wl->mutex. If another lock is needed somewhere in the
2372 * pwork callchain, it's aquired in-place, where it's needed.
2355 */ 2373 */
2356static int estimate_periodic_work_badness(unsigned int state)
2357{
2358 int badness = 0;
2359
2360 if (state % 8 == 0) /* every 120 sec */
2361 badness += 10;
2362 if (state % 4 == 0) /* every 60 sec */
2363 badness += 5;
2364 if (state % 2 == 0) /* every 30 sec */
2365 badness += 1;
2366
2367#define BADNESS_LIMIT 4
2368 return badness;
2369}
2370
2371static void b43_periodic_work_handler(struct work_struct *work) 2374static void b43_periodic_work_handler(struct work_struct *work)
2372{ 2375{
2373 struct b43_wldev *dev = 2376 struct b43_wldev *dev = container_of(work, struct b43_wldev,
2374 container_of(work, struct b43_wldev, periodic_work.work); 2377 periodic_work.work);
2375 unsigned long flags, delay; 2378 struct b43_wl *wl = dev->wl;
2376 u32 savedirqs = 0; 2379 unsigned long delay;
2377 int badness;
2378 2380
2379 mutex_lock(&dev->wl->mutex); 2381 mutex_lock(&wl->mutex);
2380 2382
2381 if (unlikely(b43_status(dev) != B43_STAT_STARTED)) 2383 if (unlikely(b43_status(dev) != B43_STAT_STARTED))
2382 goto out; 2384 goto out;
2383 if (b43_debug(dev, B43_DBG_PWORK_STOP)) 2385 if (b43_debug(dev, B43_DBG_PWORK_STOP))
2384 goto out_requeue; 2386 goto out_requeue;
2385 2387
2386 badness = estimate_periodic_work_badness(dev->periodic_state); 2388 do_periodic_work(dev);
2387 if (badness > BADNESS_LIMIT) {
2388 spin_lock_irqsave(&dev->wl->irq_lock, flags);
2389 /* Suspend TX as we don't want to transmit packets while
2390 * we recalibrate the hardware. */
2391 b43_tx_suspend(dev);
2392 savedirqs = b43_interrupt_disable(dev, B43_IRQ_ALL);
2393 /* Periodic work will take a long time, so we want it to
2394 * be preemtible and release the spinlock. */
2395 spin_unlock_irqrestore(&dev->wl->irq_lock, flags);
2396 b43_synchronize_irq(dev);
2397
2398 do_periodic_work(dev);
2399
2400 spin_lock_irqsave(&dev->wl->irq_lock, flags);
2401 b43_interrupt_enable(dev, savedirqs);
2402 b43_tx_resume(dev);
2403 mmiowb();
2404 spin_unlock_irqrestore(&dev->wl->irq_lock, flags);
2405 } else {
2406 /* Take the global driver lock. This will lock any operation. */
2407 spin_lock_irqsave(&dev->wl->irq_lock, flags);
2408
2409 do_periodic_work(dev);
2410 2389
2411 mmiowb();
2412 spin_unlock_irqrestore(&dev->wl->irq_lock, flags);
2413 }
2414 dev->periodic_state++; 2390 dev->periodic_state++;
2415out_requeue: 2391out_requeue:
2416 if (b43_debug(dev, B43_DBG_PWORK_FAST)) 2392 if (b43_debug(dev, B43_DBG_PWORK_FAST))
2417 delay = msecs_to_jiffies(50); 2393 delay = msecs_to_jiffies(50);
2418 else 2394 else
2419 delay = round_jiffies(HZ * 15); 2395 delay = round_jiffies(HZ * 15);
2420 queue_delayed_work(dev->wl->hw->workqueue, &dev->periodic_work, delay); 2396 queue_delayed_work(wl->hw->workqueue, &dev->periodic_work, delay);
2421out: 2397out:
2422 mutex_unlock(&dev->wl->mutex); 2398 mutex_unlock(&wl->mutex);
2423} 2399}
2424 2400
2425static void b43_periodic_tasks_setup(struct b43_wldev *dev) 2401static void b43_periodic_tasks_setup(struct b43_wldev *dev)