diff options
author | Helmut Schaa <helmut.schaa@googlemail.com> | 2011-08-06 13:13:48 +0200 |
---|---|---|
committer | John W. Linville <linville@tuxdriver.com> | 2011-08-09 15:52:08 -0400 |
commit | abc11994112bf7441519e35f51c29ff5de5b0d4d (patch) | |
tree | 88b11da5cdec1a7a10ff7a388d29b94902c69653 /drivers/net/wireless/rt2x00/rt2400pci.c | |
parent | c3ccb3341ec05444c8374d1829edc5157fc94853 (diff) |
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>
Diffstat (limited to 'drivers/net/wireless/rt2x00/rt2400pci.c')
-rw-r--r-- | drivers/net/wireless/rt2x00/rt2400pci.c | 39 |
1 files changed, 16 insertions, 23 deletions
diff --git a/drivers/net/wireless/rt2x00/rt2400pci.c b/drivers/net/wireless/rt2x00/rt2400pci.c index 76bcc354797..daa32fc9398 100644 --- a/drivers/net/wireless/rt2x00/rt2400pci.c +++ b/drivers/net/wireless/rt2x00/rt2400pci.c @@ -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, ®); rt2x00_set_field32(®, CSR14_TSF_COUNT, 1); rt2x00_set_field32(®, 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, ®); 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); } } @@ -1347,22 +1337,25 @@ static void rt2400pci_txstatus_tasklet(unsigned long data) /* * Enable all TXDONE interrupts again. */ - spin_lock_irq(&rt2x00dev->irqmask_lock); + if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags)) { + spin_lock_irq(&rt2x00dev->irqmask_lock); - 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); + 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_irq(&rt2x00dev->irqmask_lock); + 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); - rt2400pci_enable_interrupt(rt2x00dev, CSR8_TBCN_EXPIRE); + if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags)) + rt2400pci_enable_interrupt(rt2x00dev, CSR8_TBCN_EXPIRE); } static void rt2400pci_rxdone_tasklet(unsigned long data) @@ -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); } |