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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: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Helmut Schaa 2011-08-06 13:13:48 +02:00 committed by John W. Linville
parent c3ccb3341e
commit abc1199411
5 changed files with 64 additions and 95 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
drivers/net/wireless/rt2x00/rt2400pci.c
View File

@ -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);
@ -1356,12 +1347,14 @@ static void rt2400pci_txstatus_tasklet(unsigned long data)
rt2x00pci_register_write(rt2x00dev, CSR8, reg);
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);
}

23
drivers/net/wireless/rt2x00/rt2500pci.c
View File

@ -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);
@ -1488,12 +1479,14 @@ static void rt2500pci_txstatus_tasklet(unsigned long data)
rt2x00pci_register_write(rt2x00dev, CSR8, reg);
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);
}

40
drivers/net/wireless/rt2x00/rt2800pci.c
View File

@ -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);
}

1
drivers/net/wireless/rt2x00/rt2x00dev.c
View File

@ -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);

28
drivers/net/wireless/rt2x00/rt61pci.c
View File

@ -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);
}