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Commit bcf3cfd0 authored by Helmut Schaa's avatar Helmut Schaa Committed by John W. Linville
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rt2x00: Convert rt2400pci interrupt handling to use tasklets 



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: default avatarHelmut Schaa <helmut.schaa@googlemail.com>
Acked-by: default avatarGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: default avatarIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 16222a0d

drivers/net/wireless/rt2x00/rt2400pci.c

+115 −39
Original line number Original line Diff line number Diff line
@@ -645,6 +645,11 @@ static void rt2400pci_start_queue(struct data_queue *queue) 
		rt2x00pci_register_write(rt2x00dev, RXCSR0, reg);

		rt2x00pci_register_write(rt2x00dev, RXCSR0, reg);

		break;

		break;

	case QID_BEACON:

	case QID_BEACON:

		/*

		 * Allow the tbtt tasklet to be scheduled.

		 */

		tasklet_enable(&rt2x00dev->tbtt_tasklet);



		rt2x00pci_register_read(rt2x00dev, CSR14, &reg);

		rt2x00pci_register_read(rt2x00dev, CSR14, &reg);

		rt2x00_set_field32(&reg, CSR14_TSF_COUNT, 1);

		rt2x00_set_field32(&reg, CSR14_TSF_COUNT, 1);

		rt2x00_set_field32(&reg, CSR14_TBCN, 1);

		rt2x00_set_field32(&reg, CSR14_TBCN, 1);
@@ -706,6 +711,11 @@ static void rt2400pci_stop_queue(struct data_queue *queue) 
		rt2x00_set_field32(&reg, CSR14_TBCN, 0);

		rt2x00_set_field32(&reg, CSR14_TBCN, 0);

		rt2x00_set_field32(&reg, CSR14_BEACON_GEN, 0);

		rt2x00_set_field32(&reg, CSR14_BEACON_GEN, 0);

		rt2x00pci_register_write(rt2x00dev, CSR14, reg);

		rt2x00pci_register_write(rt2x00dev, CSR14, reg);



		/*

		 * Wait for possibly running tbtt tasklets.

		 */

		tasklet_disable(&rt2x00dev->tbtt_tasklet);

		break;

		break;

	default:

	default:

		break;

		break;
@@ -964,6 +974,7 @@ static void rt2400pci_toggle_irq(struct rt2x00_dev *rt2x00dev, 
	int mask = (state == STATE_RADIO_IRQ_OFF) ||

	int mask = (state == STATE_RADIO_IRQ_OFF) ||

		   (state == STATE_RADIO_IRQ_OFF_ISR);

		   (state == STATE_RADIO_IRQ_OFF_ISR);

	u32 reg;

	u32 reg;

	unsigned long flags;





	/*

	/*

	 * When interrupts are being enabled, the interrupt registers

	 * 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) {

	if (state == STATE_RADIO_IRQ_ON) {

		rt2x00pci_register_read(rt2x00dev, CSR7, &reg);

		rt2x00pci_register_read(rt2x00dev, CSR7, &reg);

		rt2x00pci_register_write(rt2x00dev, CSR7, reg);

		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.

	 * Only toggle the interrupts bits we are going to use.

	 * Non-checked interrupt bits are disabled by default.

	 * Non-checked interrupt bits are disabled by default.

	 */

	 */

	spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);



	rt2x00pci_register_read(rt2x00dev, CSR8, &reg);

	rt2x00pci_register_read(rt2x00dev, CSR8, &reg);

	rt2x00_set_field32(&reg, CSR8_TBCN_EXPIRE, mask);

	rt2x00_set_field32(&reg, CSR8_TBCN_EXPIRE, mask);

	rt2x00_set_field32(&reg, CSR8_TXDONE_TXRING, mask);

	rt2x00_set_field32(&reg, CSR8_TXDONE_TXRING, mask);
@@ -985,6 +1004,17 @@ static void rt2400pci_toggle_irq(struct rt2x00_dev *rt2x00dev, 
	rt2x00_set_field32(&reg, CSR8_TXDONE_PRIORING, mask);

	rt2x00_set_field32(&reg, CSR8_TXDONE_PRIORING, mask);

	rt2x00_set_field32(&reg, CSR8_RXDONE, mask);

	rt2x00_set_field32(&reg, CSR8_RXDONE, mask);

	rt2x00pci_register_write(rt2x00dev, CSR8, reg);

	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)

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;

	unsigned long flags;

	u32 reg = rt2x00dev->irqvalue[0];

	u32 reg;





	/*

	/*

	 * Handle interrupts, walk through all bits

	 * Enable a single interrupt. The interrupt mask register

	 * and run the tasks, the bits are checked in order of

	 * access needs locking.

	 * priority.

	 */

	 */

	spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);





	/*

	rt2x00pci_register_read(rt2x00dev, CSR8, &reg);

	 * 1 - Beacon timer expired interrupt.

	rt2x00_set_field32(&reg, irq_field, 0);

	 */

	rt2x00pci_register_write(rt2x00dev, CSR8, reg);

	if (rt2x00_get_field32(reg, CSR7_TBCN_EXPIRE))

		rt2x00lib_beacondone(rt2x00dev);





	/*

	spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);

	 * 2 - Rx ring done interrupt.

}

	 */

	if (rt2x00_get_field32(reg, CSR7_RXDONE))

		rt2x00pci_rxdone(rt2x00dev);





	/*

static void rt2400pci_txstatus_tasklet(unsigned long data)

	 * 3 - Atim ring transmit done interrupt.

{

	 */

	struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data;

	if (rt2x00_get_field32(reg, CSR7_TXDONE_ATIMRING))

	u32 reg;

		rt2400pci_txdone(rt2x00dev, QID_ATIM);

	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_ATIM);

	rt2400pci_txdone(rt2x00dev, QID_AC_VO);

	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))

	spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);

		rt2400pci_txdone(rt2x00dev, QID_AC_VI);





	/* Enable interrupts again. */

	rt2x00pci_register_read(rt2x00dev, CSR8, &reg);

	rt2x00dev->ops->lib->set_device_state(rt2x00dev,

	rt2x00_set_field32(&reg, CSR8_TXDONE_TXRING, 0);

					      STATE_RADIO_IRQ_ON_ISR);

	rt2x00_set_field32(&reg, CSR8_TXDONE_ATIMRING, 0);

	return IRQ_HANDLED;

	rt2x00_set_field32(&reg, 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)

static irqreturn_t rt2400pci_interrupt(int irq, void *dev_instance)

{

{

	struct rt2x00_dev *rt2x00dev = dev_instance;

	struct rt2x00_dev *rt2x00dev = dev_instance;

	u32 reg;

	u32 reg, mask;

	unsigned long flags;





	/*

	/*

	 * Get the interrupt sources & saved to local variable.

	 * 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))

	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))

		return IRQ_HANDLED;

		return IRQ_HANDLED;





	/* Store irqvalues for use in the interrupt thread. */

	mask = reg;

	rt2x00dev->irqvalue[0] = 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);





	/* Disable interrupts, will be enabled again in the interrupt thread. */

	if (rt2x00_get_field32(reg, CSR7_TXDONE_ATIMRING) ||

	rt2x00dev->ops->lib->set_device_state(rt2x00dev,

	    rt2x00_get_field32(reg, CSR7_TXDONE_PRIORING) ||

					      STATE_RADIO_IRQ_OFF_ISR);

	    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);

	}





	return IRQ_WAKE_THREAD;

	/*

	 * 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);



	rt2x00pci_register_read(rt2x00dev, CSR8, &reg);

	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 = {

static const struct rt2x00lib_ops rt2400pci_rt2x00_ops = {

	.irq_handler		= rt2400pci_interrupt,

	.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,

	.probe_hw		= rt2400pci_probe_hw,

	.initialize		= rt2x00pci_initialize,

	.initialize		= rt2x00pci_initialize,

	.uninitialize		= rt2x00pci_uninitialize,

	.uninitialize		= rt2x00pci_uninitialize,