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Commit abc11994 authored by Helmut Schaa's avatar Helmut Schaa Committed by John W. Linville
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rt2x00: Fix PCI interrupt processing race on SMP systems 



When toggle_irq is called for PCI devices to disable device interrupts
it used tasklet_disable to wait for a possibly running tasklet to finish.
However, on SMP systems the tasklet might still be scheduled on another CPU.
Instead, use tasklet_kill to ensure that all scheduled tasklets are finished
before returning from toggle_irq.

Furthermore, it was possible that a tasklet reenabled its interrupt even
though interrupts have been disabled already. Fix this by checking the
DEVICE_STATE_ENABLED_RADIO flag before reenabling single interrupts
during tasklet processing.

While at it also enable/kill the TBTT and PRETBTT tasklets in the
toggle_irq callback and only use tasklet_kill in stop_queue to wait
for a currently scheduled beacon update before returning.

Signed-off-by: default avatarHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: default avatarIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent c3ccb334

drivers/net/wireless/rt2x00/rt2400pci.c

+16 −23
Original line number Diff line number Diff line
@@ -645,11 +645,6 @@ 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, &reg);

		rt2x00_set_field32(&reg, CSR14_TSF_COUNT, 1);

		rt2x00_set_field32(&reg, CSR14_TBCN, 1);
@@ -715,7 +710,7 @@ static void rt2400pci_stop_queue(struct data_queue *queue) 
		/*

		 * Wait for possibly running tbtt tasklets.

		 */

		tasklet_disable(&rt2x00dev->tbtt_tasklet);

		tasklet_kill(&rt2x00dev->tbtt_tasklet);

		break;

	default:

		break;
@@ -982,12 +977,6 @@ static void rt2400pci_toggle_irq(struct rt2x00_dev *rt2x00dev, 
	if (state == STATE_RADIO_IRQ_ON) {

		rt2x00pci_register_read(rt2x00dev, CSR7, &reg);

		rt2x00pci_register_write(rt2x00dev, CSR7, reg);



		/*

		 * Enable tasklets.

		 */

		tasklet_enable(&rt2x00dev->txstatus_tasklet);

		tasklet_enable(&rt2x00dev->rxdone_tasklet);

	}



	/*
@@ -1011,8 +1000,9 @@ static void rt2400pci_toggle_irq(struct rt2x00_dev *rt2x00dev, 
		 * Ensure that all tasklets are finished before

		 * disabling the interrupts.

		 */

		tasklet_disable(&rt2x00dev->txstatus_tasklet);

		tasklet_disable(&rt2x00dev->rxdone_tasklet);

		tasklet_kill(&rt2x00dev->txstatus_tasklet);

		tasklet_kill(&rt2x00dev->rxdone_tasklet);

		tasklet_kill(&rt2x00dev->tbtt_tasklet);

	}

}
@@ -1347,6 +1337,7 @@ static void rt2400pci_txstatus_tasklet(unsigned long data) 
	/*

	 * Enable all TXDONE interrupts again.

	 */

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

		spin_lock_irq(&rt2x00dev->irqmask_lock);



		rt2x00pci_register_read(rt2x00dev, CSR8, &reg);
@@ -1357,11 +1348,13 @@ static void rt2400pci_txstatus_tasklet(unsigned long data) 


		spin_unlock_irq(&rt2x00dev->irqmask_lock);

	}

}



static void rt2400pci_tbtt_tasklet(unsigned long data)

{

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

	rt2x00lib_beacondone(rt2x00dev);

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

		rt2400pci_enable_interrupt(rt2x00dev, CSR8_TBCN_EXPIRE);

}
@@ -1370,7 +1363,7 @@ static void rt2400pci_rxdone_tasklet(unsigned long data) 
	struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data;

	if (rt2x00pci_rxdone(rt2x00dev))

		tasklet_schedule(&rt2x00dev->rxdone_tasklet);

	else

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

		rt2400pci_enable_interrupt(rt2x00dev, CSR8_RXDONE);

}

drivers/net/wireless/rt2x00/rt2500pci.c

+16 −23
Original line number Diff line number Diff line
@@ -735,11 +735,6 @@ static void rt2500pci_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, &reg);

		rt2x00_set_field32(&reg, CSR14_TSF_COUNT, 1);

		rt2x00_set_field32(&reg, CSR14_TBCN, 1);
@@ -805,7 +800,7 @@ static void rt2500pci_stop_queue(struct data_queue *queue) 
		/*

		 * Wait for possibly running tbtt tasklets.

		 */

		tasklet_disable(&rt2x00dev->tbtt_tasklet);

		tasklet_kill(&rt2x00dev->tbtt_tasklet);

		break;

	default:

		break;
@@ -1137,12 +1132,6 @@ static void rt2500pci_toggle_irq(struct rt2x00_dev *rt2x00dev, 
	if (state == STATE_RADIO_IRQ_ON) {

		rt2x00pci_register_read(rt2x00dev, CSR7, &reg);

		rt2x00pci_register_write(rt2x00dev, CSR7, reg);



		/*

		 * Enable tasklets.

		 */

		tasklet_enable(&rt2x00dev->txstatus_tasklet);

		tasklet_enable(&rt2x00dev->rxdone_tasklet);

	}



	/*
@@ -1165,8 +1154,9 @@ static void rt2500pci_toggle_irq(struct rt2x00_dev *rt2x00dev, 
		/*

		 * Ensure that all tasklets are finished.

		 */

		tasklet_disable(&rt2x00dev->txstatus_tasklet);

		tasklet_disable(&rt2x00dev->rxdone_tasklet);

		tasklet_kill(&rt2x00dev->txstatus_tasklet);

		tasklet_kill(&rt2x00dev->rxdone_tasklet);

		tasklet_kill(&rt2x00dev->tbtt_tasklet);

	}

}
@@ -1479,6 +1469,7 @@ static void rt2500pci_txstatus_tasklet(unsigned long data) 
	/*

	 * Enable all TXDONE interrupts again.

	 */

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

		spin_lock_irq(&rt2x00dev->irqmask_lock);



		rt2x00pci_register_read(rt2x00dev, CSR8, &reg);
@@ -1489,11 +1480,13 @@ static void rt2500pci_txstatus_tasklet(unsigned long data) 


		spin_unlock_irq(&rt2x00dev->irqmask_lock);

	}

}



static void rt2500pci_tbtt_tasklet(unsigned long data)

{

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

	rt2x00lib_beacondone(rt2x00dev);

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

		rt2500pci_enable_interrupt(rt2x00dev, CSR8_TBCN_EXPIRE);

}
@@ -1502,7 +1495,7 @@ static void rt2500pci_rxdone_tasklet(unsigned long data) 
	struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data;

	if (rt2x00pci_rxdone(rt2x00dev))

		tasklet_schedule(&rt2x00dev->rxdone_tasklet);

	else

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

		rt2500pci_enable_interrupt(rt2x00dev, CSR8_RXDONE);

}

drivers/net/wireless/rt2x00/rt2800pci.c

+19 −27
Original line number Diff line number Diff line
@@ -200,13 +200,6 @@ static void rt2800pci_start_queue(struct data_queue *queue) 
		rt2x00pci_register_write(rt2x00dev, MAC_SYS_CTRL, reg);

		break;

	case QID_BEACON:

		/*

		 * Allow beacon tasklets to be scheduled for periodic

		 * beacon updates.

		 */

		tasklet_enable(&rt2x00dev->tbtt_tasklet);

		tasklet_enable(&rt2x00dev->pretbtt_tasklet);



		rt2x00pci_register_read(rt2x00dev, BCN_TIME_CFG, &reg);

		rt2x00_set_field32(&reg, BCN_TIME_CFG_TSF_TICKING, 1);

		rt2x00_set_field32(&reg, BCN_TIME_CFG_TBTT_ENABLE, 1);
@@ -269,10 +262,13 @@ static void rt2800pci_stop_queue(struct data_queue *queue) 
		rt2x00pci_register_write(rt2x00dev, INT_TIMER_EN, reg);



		/*

		 * Wait for tbtt tasklets to finish.

		 * Wait for current invocation to finish. The tasklet

		 * won't be scheduled anymore afterwards since we disabled

		 * the TBTT and PRE TBTT timer.

		 */

		tasklet_disable(&rt2x00dev->tbtt_tasklet);

		tasklet_disable(&rt2x00dev->pretbtt_tasklet);

		tasklet_kill(&rt2x00dev->tbtt_tasklet);

		tasklet_kill(&rt2x00dev->pretbtt_tasklet);



		break;

	default:

		break;
@@ -437,14 +433,6 @@ static void rt2800pci_toggle_irq(struct rt2x00_dev *rt2x00dev, 
	if (state == STATE_RADIO_IRQ_ON) {

		rt2x00pci_register_read(rt2x00dev, INT_SOURCE_CSR, &reg);

		rt2x00pci_register_write(rt2x00dev, INT_SOURCE_CSR, reg);



		/*

		 * Enable tasklets. The beacon related tasklets are

		 * enabled when the beacon queue is started.

		 */

		tasklet_enable(&rt2x00dev->txstatus_tasklet);

		tasklet_enable(&rt2x00dev->rxdone_tasklet);

		tasklet_enable(&rt2x00dev->autowake_tasklet);

	}



	spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
@@ -472,12 +460,13 @@ static void rt2800pci_toggle_irq(struct rt2x00_dev *rt2x00dev, 


	if (state == STATE_RADIO_IRQ_OFF) {

		/*

		 * Ensure that all tasklets are finished before

		 * disabling the interrupts.

		 * Wait for possibly running tasklets to finish.

		 */

		tasklet_disable(&rt2x00dev->txstatus_tasklet);

		tasklet_disable(&rt2x00dev->rxdone_tasklet);

		tasklet_disable(&rt2x00dev->autowake_tasklet);

		tasklet_kill(&rt2x00dev->txstatus_tasklet);

		tasklet_kill(&rt2x00dev->rxdone_tasklet);

		tasklet_kill(&rt2x00dev->autowake_tasklet);

		tasklet_kill(&rt2x00dev->tbtt_tasklet);

		tasklet_kill(&rt2x00dev->pretbtt_tasklet);

	}

}
@@ -813,6 +802,7 @@ static void rt2800pci_pretbtt_tasklet(unsigned long data) 
{

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

	rt2x00lib_pretbtt(rt2x00dev);

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

		rt2800pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_PRE_TBTT);

}
@@ -820,6 +810,7 @@ static void rt2800pci_tbtt_tasklet(unsigned long data) 
{

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

	rt2x00lib_beacondone(rt2x00dev);

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

		rt2800pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_TBTT);

}
@@ -828,7 +819,7 @@ static void rt2800pci_rxdone_tasklet(unsigned long data) 
	struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data;

	if (rt2x00pci_rxdone(rt2x00dev))

		tasklet_schedule(&rt2x00dev->rxdone_tasklet);

	else

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

		rt2800pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_RX_DONE);

}
@@ -836,6 +827,7 @@ static void rt2800pci_autowake_tasklet(unsigned long data) 
{

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

	rt2800pci_wakeup(rt2x00dev);

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

		rt2800pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_AUTO_WAKEUP);

}

drivers/net/wireless/rt2x00/rt2x00dev.c

+0 −1
Original line number Diff line number Diff line
@@ -946,7 +946,6 @@ static int rt2x00lib_probe_hw(struct rt2x00_dev *rt2x00dev) 
		tasklet_init(&rt2x00dev->taskletname, \

			     rt2x00dev->ops->lib->taskletname, \

			     (unsigned long)rt2x00dev); \

		tasklet_disable(&rt2x00dev->taskletname); \

	}



	RT2X00_TASKLET_INIT(txstatus_tasklet);

drivers/net/wireless/rt2x00/rt61pci.c

+13 −21
Original line number Diff line number Diff line
@@ -1142,11 +1142,6 @@ static void rt61pci_start_queue(struct data_queue *queue) 
		rt2x00pci_register_write(rt2x00dev, TXRX_CSR0, reg);

		break;

	case QID_BEACON:

		/*

		 * Allow the tbtt tasklet to be scheduled.

		 */

		tasklet_enable(&rt2x00dev->tbtt_tasklet);



		rt2x00pci_register_read(rt2x00dev, TXRX_CSR9, &reg);

		rt2x00_set_field32(&reg, TXRX_CSR9_TSF_TICKING, 1);

		rt2x00_set_field32(&reg, TXRX_CSR9_TBTT_ENABLE, 1);
@@ -1230,7 +1225,7 @@ static void rt61pci_stop_queue(struct data_queue *queue) 
		/*

		 * Wait for possibly running tbtt tasklets.

		 */

		tasklet_disable(&rt2x00dev->tbtt_tasklet);

		tasklet_kill(&rt2x00dev->tbtt_tasklet);

		break;

	default:

		break;
@@ -1731,13 +1726,6 @@ static void rt61pci_toggle_irq(struct rt2x00_dev *rt2x00dev, 


		rt2x00pci_register_read(rt2x00dev, MCU_INT_SOURCE_CSR, &reg);

		rt2x00pci_register_write(rt2x00dev, MCU_INT_SOURCE_CSR, reg);



		/*

		 * Enable tasklets.

		 */

		tasklet_enable(&rt2x00dev->txstatus_tasklet);

		tasklet_enable(&rt2x00dev->rxdone_tasklet);

		tasklet_enable(&rt2x00dev->autowake_tasklet);

	}



	/*
@@ -1772,9 +1760,10 @@ static void rt61pci_toggle_irq(struct rt2x00_dev *rt2x00dev, 
		/*

		 * Ensure that all tasklets are finished.

		 */

		tasklet_disable(&rt2x00dev->txstatus_tasklet);

		tasklet_disable(&rt2x00dev->rxdone_tasklet);

		tasklet_disable(&rt2x00dev->autowake_tasklet);

		tasklet_kill(&rt2x00dev->txstatus_tasklet);

		tasklet_kill(&rt2x00dev->rxdone_tasklet);

		tasklet_kill(&rt2x00dev->autowake_tasklet);

		tasklet_kill(&rt2x00dev->tbtt_tasklet);

	}

}
@@ -2300,6 +2289,7 @@ static void rt61pci_txstatus_tasklet(unsigned long data) 
{

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

	rt61pci_txdone(rt2x00dev);

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

		rt61pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_TXDONE);

}
@@ -2307,6 +2297,7 @@ static void rt61pci_tbtt_tasklet(unsigned long data) 
{

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

	rt2x00lib_beacondone(rt2x00dev);

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

		rt61pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_BEACON_DONE);

}
@@ -2314,8 +2305,8 @@ static void rt61pci_rxdone_tasklet(unsigned long data) 
{

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

	if (rt2x00pci_rxdone(rt2x00dev))

		rt2x00pci_rxdone(rt2x00dev);

	else

		tasklet_schedule(&rt2x00dev->rxdone_tasklet);

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

		rt61pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_RXDONE);

}
@@ -2325,6 +2316,7 @@ static void rt61pci_autowake_tasklet(unsigned long data) 
	rt61pci_wakeup(rt2x00dev);

	rt2x00pci_register_write(rt2x00dev,

				 M2H_CMD_DONE_CSR, 0xffffffff);

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

		rt61pci_enable_mcu_interrupt(rt2x00dev, MCU_INT_MASK_CSR_TWAKEUP);

}