From: Helmut Schaa <helmut.schaa@xxxxxxxxxxxxxx>
Fix interrupt processing on slow machines by using individual tasklets
for each different device interrupt. This ensures that while a RX or TX
status tasklet is scheduled only the according device interrupt is
masked and other interrupts such as TBTT can still be processed.
Also, this allows us to use tasklet_hi_schedule for TBTT processing
which is required to not send out beacons with a wrong DTIM count (due
to delayed periodic beacon updates). Furthermore, this improves the
latency between the TBTT and sending out buffered multi- and broadcast
traffic.
As a nice bonus, the interrupt handling overhead should be much lower.
Compile-tested only.
Signed-off-by: Helmut Schaa <helmut.schaa@xxxxxxxxxxxxxx>
Acked-by: Gertjan van Wingerde <gwingerde@xxxxxxxxx>
Signed-off-by: Ivo van Doorn <IvDoorn@xxxxxxxxx>
---
drivers/net/wireless/rt2x00/rt2400pci.c | 154 +++++++++++++++++++++++--------
1 files changed, 115 insertions(+), 39 deletions(-)
diff --git a/drivers/net/wireless/rt2x00/rt2400pci.c b/drivers/net/wireless/rt2x00/rt2400pci.c
index cb28e1b..b324917 100644
--- a/drivers/net/wireless/rt2x00/rt2400pci.c
+++ b/drivers/net/wireless/rt2x00/rt2400pci.c
@@ -645,6 +645,11 @@ static void rt2400pci_start_queue(struct data_queue *queue)
rt2x00pci_register_write(rt2x00dev, RXCSR0, reg);
break;
case QID_BEACON:
+ /*
+ * Allow the tbtt tasklet to be scheduled.
+ */
+ tasklet_enable(&rt2x00dev->tbtt_tasklet);
+
rt2x00pci_register_read(rt2x00dev, CSR14, ®);
rt2x00_set_field32(®, CSR14_TSF_COUNT, 1);
rt2x00_set_field32(®, CSR14_TBCN, 1);
@@ -706,6 +711,11 @@ static void rt2400pci_stop_queue(struct data_queue *queue)
rt2x00_set_field32(®, CSR14_TBCN, 0);
rt2x00_set_field32(®, CSR14_BEACON_GEN, 0);
rt2x00pci_register_write(rt2x00dev, CSR14, reg);
+
+ /*
+ * Wait for possibly running tbtt tasklets.
+ */
+ tasklet_disable(&rt2x00dev->tbtt_tasklet);
break;
default:
break;
@@ -964,6 +974,7 @@ static void rt2400pci_toggle_irq(struct rt2x00_dev *rt2x00dev,
int mask = (state == STATE_RADIO_IRQ_OFF) ||
(state == STATE_RADIO_IRQ_OFF_ISR);
u32 reg;
+ unsigned long flags;
/*
* When interrupts are being enabled, the interrupt registers
@@ -972,12 +983,20 @@ static void rt2400pci_toggle_irq(struct rt2x00_dev *rt2x00dev,
if (state == STATE_RADIO_IRQ_ON) {
rt2x00pci_register_read(rt2x00dev, CSR7, ®);
rt2x00pci_register_write(rt2x00dev, CSR7, reg);
+
+ /*
+ * Enable tasklets.
+ */
+ tasklet_enable(&rt2x00dev->txstatus_tasklet);
+ tasklet_enable(&rt2x00dev->rxdone_tasklet);
}
/*
* Only toggle the interrupts bits we are going to use.
* Non-checked interrupt bits are disabled by default.
*/
+ spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
+
rt2x00pci_register_read(rt2x00dev, CSR8, ®);
rt2x00_set_field32(®, CSR8_TBCN_EXPIRE, mask);
rt2x00_set_field32(®, CSR8_TXDONE_TXRING, mask);
@@ -985,6 +1004,17 @@ static void rt2400pci_toggle_irq(struct rt2x00_dev *rt2x00dev,
rt2x00_set_field32(®, CSR8_TXDONE_PRIORING, mask);
rt2x00_set_field32(®, CSR8_RXDONE, mask);
rt2x00pci_register_write(rt2x00dev, CSR8, reg);
+
+ spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+
+ if (state == STATE_RADIO_IRQ_OFF) {
+ /*
+ * Ensure that all tasklets are finished before
+ * disabling the interrupts.
+ */
+ tasklet_disable(&rt2x00dev->txstatus_tasklet);
+ tasklet_disable(&rt2x00dev->rxdone_tasklet);
+ }
}
static int rt2400pci_enable_radio(struct rt2x00_dev *rt2x00dev)
@@ -1285,57 +1315,71 @@ static void rt2400pci_txdone(struct rt2x00_dev *rt2x00dev,
}
}
-static irqreturn_t rt2400pci_interrupt_thread(int irq, void *dev_instance)
+static void rt2400pci_enable_interrupt(struct rt2x00_dev *rt2x00dev,
+ struct rt2x00_field32 irq_field)
{
- struct rt2x00_dev *rt2x00dev = dev_instance;
- u32 reg = rt2x00dev->irqvalue[0];
+ unsigned long flags;
+ u32 reg;
/*
- * Handle interrupts, walk through all bits
- * and run the tasks, the bits are checked in order of
- * priority.
+ * Enable a single interrupt. The interrupt mask register
+ * access needs locking.
*/
+ spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
- /*
- * 1 - Beacon timer expired interrupt.
- */
- if (rt2x00_get_field32(reg, CSR7_TBCN_EXPIRE))
- rt2x00lib_beacondone(rt2x00dev);
+ rt2x00pci_register_read(rt2x00dev, CSR8, ®);
+ rt2x00_set_field32(®, irq_field, 0);
+ rt2x00pci_register_write(rt2x00dev, CSR8, reg);
- /*
- * 2 - Rx ring done interrupt.
- */
- if (rt2x00_get_field32(reg, CSR7_RXDONE))
- rt2x00pci_rxdone(rt2x00dev);
+ spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+}
- /*
- * 3 - Atim ring transmit done interrupt.
- */
- if (rt2x00_get_field32(reg, CSR7_TXDONE_ATIMRING))
- rt2400pci_txdone(rt2x00dev, QID_ATIM);
+static void rt2400pci_txstatus_tasklet(unsigned long data)
+{
+ struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data;
+ u32 reg;
+ unsigned long flags;
/*
- * 4 - Priority ring transmit done interrupt.
+ * Handle all tx queues.
*/
- if (rt2x00_get_field32(reg, CSR7_TXDONE_PRIORING))
- rt2400pci_txdone(rt2x00dev, QID_AC_VO);
+ rt2400pci_txdone(rt2x00dev, QID_ATIM);
+ rt2400pci_txdone(rt2x00dev, QID_AC_VO);
+ rt2400pci_txdone(rt2x00dev, QID_AC_VI);
/*
- * 5 - Tx ring transmit done interrupt.
+ * Enable all TXDONE interrupts again.
*/
- if (rt2x00_get_field32(reg, CSR7_TXDONE_TXRING))
- rt2400pci_txdone(rt2x00dev, QID_AC_VI);
+ spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
- /* Enable interrupts again. */
- rt2x00dev->ops->lib->set_device_state(rt2x00dev,
- STATE_RADIO_IRQ_ON_ISR);
- return IRQ_HANDLED;
+ rt2x00pci_register_read(rt2x00dev, CSR8, ®);
+ rt2x00_set_field32(®, CSR8_TXDONE_TXRING, 0);
+ rt2x00_set_field32(®, CSR8_TXDONE_ATIMRING, 0);
+ rt2x00_set_field32(®, CSR8_TXDONE_PRIORING, 0);
+ rt2x00pci_register_write(rt2x00dev, CSR8, reg);
+
+ spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+}
+
+static void rt2400pci_tbtt_tasklet(unsigned long data)
+{
+ struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data;
+ rt2x00lib_beacondone(rt2x00dev);
+ rt2400pci_enable_interrupt(rt2x00dev, CSR8_TBCN_EXPIRE);
+}
+
+static void rt2400pci_rxdone_tasklet(unsigned long data)
+{
+ struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data;
+ rt2x00pci_rxdone(rt2x00dev);
+ rt2400pci_enable_interrupt(rt2x00dev, CSR8_RXDONE);
}
static irqreturn_t rt2400pci_interrupt(int irq, void *dev_instance)
{
struct rt2x00_dev *rt2x00dev = dev_instance;
- u32 reg;
+ u32 reg, mask;
+ unsigned long flags;
/*
* Get the interrupt sources & saved to local variable.
@@ -1350,14 +1394,44 @@ static irqreturn_t rt2400pci_interrupt(int irq, void *dev_instance)
if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
return IRQ_HANDLED;
- /* Store irqvalues for use in the interrupt thread. */
- rt2x00dev->irqvalue[0] = reg;
+ mask = reg;
+
+ /*
+ * Schedule tasklets for interrupt handling.
+ */
+ if (rt2x00_get_field32(reg, CSR7_TBCN_EXPIRE))
+ tasklet_hi_schedule(&rt2x00dev->tbtt_tasklet);
+
+ if (rt2x00_get_field32(reg, CSR7_RXDONE))
+ tasklet_schedule(&rt2x00dev->rxdone_tasklet);
+
+ if (rt2x00_get_field32(reg, CSR7_TXDONE_ATIMRING) ||
+ rt2x00_get_field32(reg, CSR7_TXDONE_PRIORING) ||
+ rt2x00_get_field32(reg, CSR7_TXDONE_TXRING)) {
+ tasklet_schedule(&rt2x00dev->txstatus_tasklet);
+ /*
+ * Mask out all txdone interrupts.
+ */
+ rt2x00_set_field32(&mask, CSR8_TXDONE_TXRING, 1);
+ rt2x00_set_field32(&mask, CSR8_TXDONE_ATIMRING, 1);
+ rt2x00_set_field32(&mask, CSR8_TXDONE_PRIORING, 1);
+ }
- /* Disable interrupts, will be enabled again in the interrupt thread. */
- rt2x00dev->ops->lib->set_device_state(rt2x00dev,
- STATE_RADIO_IRQ_OFF_ISR);
+ /*
+ * Disable all interrupts for which a tasklet was scheduled right now,
+ * the tasklet will reenable the appropriate interrupts.
+ */
+ spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
- return IRQ_WAKE_THREAD;
+ rt2x00pci_register_read(rt2x00dev, CSR8, ®);
+ reg |= mask;
+ rt2x00pci_register_write(rt2x00dev, CSR8, reg);
+
+ spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+
+
+
+ return IRQ_HANDLED;
}
/*
@@ -1651,7 +1725,9 @@ static const struct ieee80211_ops rt2400pci_mac80211_ops = {
static const struct rt2x00lib_ops rt2400pci_rt2x00_ops = {
.irq_handler = rt2400pci_interrupt,
- .irq_handler_thread = rt2400pci_interrupt_thread,
+ .txstatus_tasklet = rt2400pci_txstatus_tasklet,
+ .tbtt_tasklet = rt2400pci_tbtt_tasklet,
+ .rxdone_tasklet = rt2400pci_rxdone_tasklet,
.probe_hw = rt2400pci_probe_hw,
.initialize = rt2x00pci_initialize,
.uninitialize = rt2x00pci_uninitialize,
--
1.7.2.3
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