[PATCH] bcm43xx: preemptible periodic work
Make the heavy periodic work preemptible to avoid disabling
local IRQs for several msecs.
Signed-off-by: Michael Buesch <mb@buesch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/bcm43xx/bcm43xx_main.c b/drivers/net/wireless/bcm43xx/bcm43xx_main.c
index 835a2df..77d0e39 100644
--- a/drivers/net/wireless/bcm43xx/bcm43xx_main.c
+++ b/drivers/net/wireless/bcm43xx/bcm43xx_main.c
@@ -498,11 +498,21 @@
return old_mask;
}
+/* Synchronize IRQ top- and bottom-half.
+ * IRQs must be masked before calling this.
+ * This must not be called with the irq_lock held.
+ */
+static void bcm43xx_synchronize_irq(struct bcm43xx_private *bcm)
+{
+ synchronize_irq(bcm->irq);
+ tasklet_disable(&bcm->isr_tasklet);
+}
+
/* Make sure we don't receive more data from the device. */
static int bcm43xx_disable_interrupts_sync(struct bcm43xx_private *bcm, u32 *oldstate)
{
- u32 old;
unsigned long flags;
+ u32 old;
bcm43xx_lock_irqonly(bcm, flags);
if (unlikely(bcm43xx_status(bcm) != BCM43xx_STAT_INITIALIZED)) {
@@ -510,8 +520,9 @@
return -EBUSY;
}
old = bcm43xx_interrupt_disable(bcm, BCM43xx_IRQ_ALL);
- tasklet_disable(&bcm->isr_tasklet);
bcm43xx_unlock_irqonly(bcm, flags);
+ bcm43xx_synchronize_irq(bcm);
+
if (oldstate)
*oldstate = old;
@@ -3108,14 +3119,10 @@
//TODO for APHY (temperature?)
}
-static void bcm43xx_periodic_work_handler(void *d)
+static void do_periodic_work(struct bcm43xx_private *bcm)
{
- struct bcm43xx_private *bcm = d;
- unsigned long flags;
unsigned int state;
- bcm43xx_lock_irqsafe(bcm, flags);
-
state = bcm->periodic_state;
if (state % 8 == 0)
bcm43xx_periodic_every120sec(bcm);
@@ -3123,13 +3130,79 @@
bcm43xx_periodic_every60sec(bcm);
if (state % 2 == 0)
bcm43xx_periodic_every30sec(bcm);
- bcm43xx_periodic_every15sec(bcm);
+ if (state % 1 == 0)
+ bcm43xx_periodic_every15sec(bcm);
bcm->periodic_state = state + 1;
schedule_delayed_work(&bcm->periodic_work, HZ * 15);
+}
- mmiowb();
- bcm43xx_unlock_irqsafe(bcm, flags);
+/* Estimate a "Badness" value based on the periodic work
+ * state-machine state. "Badness" is worse (bigger), if the
+ * periodic work will take longer.
+ */
+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;
+ if (state % 1 == 0) /* every 15 sec */
+ badness += 1;
+
+#define BADNESS_LIMIT 4
+ return badness;
+}
+
+static void bcm43xx_periodic_work_handler(void *d)
+{
+ struct bcm43xx_private *bcm = d;
+ unsigned long flags;
+ u32 savedirqs = 0;
+ int badness;
+
+ badness = estimate_periodic_work_badness(bcm->periodic_state);
+ if (badness > BADNESS_LIMIT) {
+ /* Periodic work will take a long time, so we want it to
+ * be preemtible.
+ */
+ bcm43xx_lock_irqonly(bcm, flags);
+ netif_stop_queue(bcm->net_dev);
+ if (bcm43xx_using_pio(bcm))
+ bcm43xx_pio_freeze_txqueues(bcm);
+ savedirqs = bcm43xx_interrupt_disable(bcm, BCM43xx_IRQ_ALL);
+ bcm43xx_unlock_irqonly(bcm, flags);
+ bcm43xx_lock_noirq(bcm);
+ bcm43xx_synchronize_irq(bcm);
+ } else {
+ /* Periodic work should take short time, so we want low
+ * locking overhead.
+ */
+ bcm43xx_lock_irqsafe(bcm, flags);
+ }
+
+ do_periodic_work(bcm);
+
+ if (badness > BADNESS_LIMIT) {
+ bcm43xx_lock_irqonly(bcm, flags);
+ if (likely(bcm43xx_status(bcm) == BCM43xx_STAT_INITIALIZED)) {
+ tasklet_enable(&bcm->isr_tasklet);
+ bcm43xx_interrupt_enable(bcm, savedirqs);
+ if (bcm43xx_using_pio(bcm))
+ bcm43xx_pio_thaw_txqueues(bcm);
+ }
+ netif_wake_queue(bcm->net_dev);
+ mmiowb();
+ bcm43xx_unlock_irqonly(bcm, flags);
+ bcm43xx_unlock_noirq(bcm);
+ } else {
+ mmiowb();
+ bcm43xx_unlock_irqsafe(bcm, flags);
+ }
}
static void bcm43xx_periodic_tasks_delete(struct bcm43xx_private *bcm)
@@ -3670,9 +3743,11 @@
static int bcm43xx_net_stop(struct net_device *net_dev)
{
struct bcm43xx_private *bcm = bcm43xx_priv(net_dev);
+ int err;
ieee80211softmac_stop(net_dev);
- bcm43xx_disable_interrupts_sync(bcm, NULL);
+ err = bcm43xx_disable_interrupts_sync(bcm, NULL);
+ assert(!err);
bcm43xx_free_board(bcm);
return 0;
diff --git a/drivers/net/wireless/bcm43xx/bcm43xx_phy.c b/drivers/net/wireless/bcm43xx/bcm43xx_phy.c
index 952c2f8..f8200de 100644
--- a/drivers/net/wireless/bcm43xx/bcm43xx_phy.c
+++ b/drivers/net/wireless/bcm43xx/bcm43xx_phy.c
@@ -1410,7 +1410,10 @@
u16 bcm43xx_phy_lo_g_deviation_subval(struct bcm43xx_private *bcm, u16 control)
{
struct bcm43xx_phyinfo *phy = bcm43xx_current_phy(bcm);
+ u16 ret;
+ unsigned long flags;
+ local_irq_save(flags);
if (phy->connected) {
bcm43xx_phy_write(bcm, 0x15, 0xE300);
control <<= 8;
@@ -1430,8 +1433,10 @@
bcm43xx_phy_write(bcm, 0x0015, control | 0xFFE0);
udelay(8);
}
+ ret = bcm43xx_phy_read(bcm, 0x002D);
+ local_irq_restore(flags);
- return bcm43xx_phy_read(bcm, 0x002D);
+ return ret;
}
static u32 bcm43xx_phy_lo_g_singledeviation(struct bcm43xx_private *bcm, u16 control)
diff --git a/drivers/net/wireless/bcm43xx/bcm43xx_pio.c b/drivers/net/wireless/bcm43xx/bcm43xx_pio.c
index e77e9d8..574085c 100644
--- a/drivers/net/wireless/bcm43xx/bcm43xx_pio.c
+++ b/drivers/net/wireless/bcm43xx/bcm43xx_pio.c
@@ -264,6 +264,8 @@
bcm43xx_lock_irqonly(bcm, flags);
+ if (queue->tx_frozen)
+ goto out_unlock;
txctl = bcm43xx_pio_read(queue, BCM43xx_PIO_TXCTL);
if (txctl & BCM43xx_PIO_TXCTL_SUSPEND)
goto out_unlock;
@@ -633,5 +635,40 @@
bcm43xx_pio_read(queue, BCM43xx_PIO_TXCTL)
& ~BCM43xx_PIO_TXCTL_SUSPEND);
bcm43xx_power_saving_ctl_bits(queue->bcm, -1, -1);
- tasklet_schedule(&queue->txtask);
+ if (!list_empty(&queue->txqueue))
+ tasklet_schedule(&queue->txtask);
}
+
+void bcm43xx_pio_freeze_txqueues(struct bcm43xx_private *bcm)
+{
+ struct bcm43xx_pio *pio;
+
+ assert(bcm43xx_using_pio(bcm));
+ pio = bcm43xx_current_pio(bcm);
+ pio->queue0->tx_frozen = 1;
+ pio->queue1->tx_frozen = 1;
+ pio->queue2->tx_frozen = 1;
+ pio->queue3->tx_frozen = 1;
+}
+
+void bcm43xx_pio_thaw_txqueues(struct bcm43xx_private *bcm)
+{
+ struct bcm43xx_pio *pio;
+
+ assert(bcm43xx_using_pio(bcm));
+ pio = bcm43xx_current_pio(bcm);
+ pio->queue0->tx_frozen = 0;
+ pio->queue1->tx_frozen = 0;
+ pio->queue2->tx_frozen = 0;
+ pio->queue3->tx_frozen = 0;
+ if (!list_empty(&pio->queue0->txqueue))
+ tasklet_schedule(&pio->queue0->txtask);
+ if (!list_empty(&pio->queue1->txqueue))
+ tasklet_schedule(&pio->queue1->txtask);
+ if (!list_empty(&pio->queue2->txqueue))
+ tasklet_schedule(&pio->queue2->txtask);
+ if (!list_empty(&pio->queue3->txqueue))
+ tasklet_schedule(&pio->queue3->txtask);
+}
+
+
diff --git a/drivers/net/wireless/bcm43xx/bcm43xx_pio.h b/drivers/net/wireless/bcm43xx/bcm43xx_pio.h
index dfc7820..bc78a3c 100644
--- a/drivers/net/wireless/bcm43xx/bcm43xx_pio.h
+++ b/drivers/net/wireless/bcm43xx/bcm43xx_pio.h
@@ -54,6 +54,7 @@
u16 mmio_base;
u8 tx_suspended:1,
+ tx_frozen:1,
need_workarounds:1; /* Workarounds needed for core.rev < 3 */
/* Adjusted size of the device internal TX buffer. */
@@ -108,8 +109,12 @@
struct bcm43xx_xmitstatus *status);
void bcm43xx_pio_rx(struct bcm43xx_pioqueue *queue);
+/* Suspend a TX queue on hardware level. */
void bcm43xx_pio_tx_suspend(struct bcm43xx_pioqueue *queue);
void bcm43xx_pio_tx_resume(struct bcm43xx_pioqueue *queue);
+/* Suspend (freeze) the TX tasklet (software level). */
+void bcm43xx_pio_freeze_txqueues(struct bcm43xx_private *bcm);
+void bcm43xx_pio_thaw_txqueues(struct bcm43xx_private *bcm);
#else /* CONFIG_BCM43XX_PIO */
@@ -145,6 +150,14 @@
void bcm43xx_pio_tx_resume(struct bcm43xx_pioqueue *queue)
{
}
+static inline
+void bcm43xx_pio_freeze_txqueues(struct bcm43xx_private *bcm)
+{
+}
+static inline
+void bcm43xx_pio_thaw_txqueues(struct bcm43xx_private *bcm)
+{
+}
#endif /* CONFIG_BCM43XX_PIO */
#endif /* BCM43xx_PIO_H_ */