[PATCH] bcm43xx: suspend MAC while executing long pwork

Suspend MAC (and make MAC-suspend refcounting) when doing
long periodic work.
On long periodic work, we disable IRQs on the device, so
we don't want the MAC to stay operating and probably miss
packets due do non-delivery of interrupts.
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/bcm43xx/bcm43xx.h

@@ -737,6 +737,8 @@ struct bcm43xx_private {
 	u32 irq_savedstate;
 	/* Link Quality calculation context. */
 	struct bcm43xx_noise_calculation noisecalc;
+	/* if > 0 MAC is suspended. if == 0 MAC is enabled. */
+	int mac_suspended;
 
 	/* Threshold values. */
 	//TODO: The RTS thr has to be _used_. Currently, it is only set via WX.

drivers/net/wireless/bcm43xx/bcm43xx_main.c

@@ -2298,6 +2298,9 @@ static int bcm43xx_gpio_cleanup(struct bcm43xx_private *bcm)
 /* http://bcm-specs.sipsolutions.net/EnableMac */
 void bcm43xx_mac_enable(struct bcm43xx_private *bcm)
 {
+	bcm->mac_suspended--;
+	assert(bcm->mac_suspended >= 0);
+	if (bcm->mac_suspended == 0) {
 		bcm43xx_write32(bcm, BCM43xx_MMIO_STATUS_BITFIELD,
 		                bcm43xx_read32(bcm, BCM43xx_MMIO_STATUS_BITFIELD)
 				| BCM43xx_SBF_MAC_ENABLED);
@@ -2305,6 +2308,7 @@ void bcm43xx_mac_enable(struct bcm43xx_private *bcm)
 		bcm43xx_read32(bcm, BCM43xx_MMIO_STATUS_BITFIELD); /* dummy read */
 		bcm43xx_read32(bcm, BCM43xx_MMIO_GEN_IRQ_REASON); /* dummy read */
 		bcm43xx_power_saving_ctl_bits(bcm, -1, -1);
+	}
 }
 
 /* http://bcm-specs.sipsolutions.net/SuspendMAC */
@@ -2313,6 +2317,8 @@ void bcm43xx_mac_suspend(struct bcm43xx_private *bcm)
 	int i;
 	u32 tmp;
 
+	assert(bcm->mac_suspended >= 0);
+	if (bcm->mac_suspended == 0) {
 		bcm43xx_power_saving_ctl_bits(bcm, -1, 1);
 		bcm43xx_write32(bcm, BCM43xx_MMIO_STATUS_BITFIELD,
 		                bcm43xx_read32(bcm, BCM43xx_MMIO_STATUS_BITFIELD)
@@ -2321,10 +2327,13 @@ void bcm43xx_mac_suspend(struct bcm43xx_private *bcm)
 		for (i = 100000; i; i--) {
 			tmp = bcm43xx_read32(bcm, BCM43xx_MMIO_GEN_IRQ_REASON);
 			if (tmp & BCM43xx_IRQ_READY)
-			return;
+				goto out;
 			udelay(10);
 		}
 		printkl(KERN_ERR PFX "MAC suspend failed\n");
+	}
+out:
+	bcm->mac_suspended++;
 }
 
 void bcm43xx_set_iwmode(struct bcm43xx_private *bcm,
@@ -3183,7 +3192,9 @@ static void bcm43xx_periodic_work_handler(void *d)
 		 * be preemtible.
 		 */
 		netif_stop_queue(bcm->net_dev);
+		synchronize_net();
 		spin_lock_irqsave(&bcm->irq_lock, flags);
+		bcm43xx_mac_suspend(bcm);
 		if (bcm43xx_using_pio(bcm))
 			bcm43xx_pio_freeze_txqueues(bcm);
 		savedirqs = bcm43xx_interrupt_disable(bcm, BCM43xx_IRQ_ALL);
@@ -3207,6 +3218,7 @@ static void bcm43xx_periodic_work_handler(void *d)
 			bcm43xx_interrupt_enable(bcm, savedirqs);
 			if (bcm43xx_using_pio(bcm))
 				bcm43xx_pio_thaw_txqueues(bcm);
+			bcm43xx_mac_enable(bcm);
 		}
 		netif_wake_queue(bcm->net_dev);
 	}
@@ -3820,6 +3832,7 @@ static int bcm43xx_init_private(struct bcm43xx_private *bcm,
 	bcm->softmac->set_channel = bcm43xx_ieee80211_set_chan;
 
 	bcm->irq_savedstate = BCM43xx_IRQ_INITIAL;
+	bcm->mac_suspended = 1;
 	bcm->pci_dev = pci_dev;
 	bcm->net_dev = net_dev;
 	bcm->bad_frames_preempt = modparam_bad_frames_preempt;