From: Helmut Schaa Date: Sat, 6 Aug 2011 11:13:48 +0000 (+0200) Subject: rt2x00: Fix PCI interrupt processing race on SMP systems X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=abc11994112bf7441519e35f51c29ff5de5b0d4d;p=openwrt%2Fstaging%2Fblogic.git 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 Signed-off-by: Ivo van Doorn Signed-off-by: John W. Linville --- diff --git a/drivers/net/wireless/rt2x00/rt2400pci.c b/drivers/net/wireless/rt2x00/rt2400pci.c index 76bcc3547976..daa32fc9398b 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); } diff --git a/drivers/net/wireless/rt2x00/rt2500pci.c b/drivers/net/wireless/rt2x00/rt2500pci.c index c288d951c034..b46c3b8866fa 100644 --- a/drivers/net/wireless/rt2x00/rt2500pci.c +++ b/drivers/net/wireless/rt2x00/rt2500pci.c @@ -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, ®); rt2x00_set_field32(®, CSR14_TSF_COUNT, 1); rt2x00_set_field32(®, 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, ®); 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); } } @@ -1479,22 +1469,25 @@ static void rt2500pci_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 rt2500pci_tbtt_tasklet(unsigned long data) { struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data; rt2x00lib_beacondone(rt2x00dev); - rt2500pci_enable_interrupt(rt2x00dev, CSR8_TBCN_EXPIRE); + if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags)) + rt2500pci_enable_interrupt(rt2x00dev, CSR8_TBCN_EXPIRE); } static void rt2500pci_rxdone_tasklet(unsigned long data) @@ -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); } diff --git a/drivers/net/wireless/rt2x00/rt2800pci.c b/drivers/net/wireless/rt2x00/rt2800pci.c index ebc17ad61dec..cabf249aa55b 100644 --- a/drivers/net/wireless/rt2x00/rt2800pci.c +++ b/drivers/net/wireless/rt2x00/rt2800pci.c @@ -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, ®); rt2x00_set_field32(®, BCN_TIME_CFG_TSF_TICKING, 1); rt2x00_set_field32(®, 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, ®); 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); } } @@ -813,14 +802,16 @@ static void rt2800pci_pretbtt_tasklet(unsigned long data) { struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data; rt2x00lib_pretbtt(rt2x00dev); - rt2800pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_PRE_TBTT); + if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags)) + rt2800pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_PRE_TBTT); } static void rt2800pci_tbtt_tasklet(unsigned long data) { struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data; rt2x00lib_beacondone(rt2x00dev); - rt2800pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_TBTT); + if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags)) + rt2800pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_TBTT); } static void rt2800pci_rxdone_tasklet(unsigned long data) @@ -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); } @@ -836,7 +827,8 @@ static void rt2800pci_autowake_tasklet(unsigned long data) { struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data; rt2800pci_wakeup(rt2x00dev); - rt2800pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_AUTO_WAKEUP); + if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags)) + rt2800pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_AUTO_WAKEUP); } static void rt2800pci_txstatus_interrupt(struct rt2x00_dev *rt2x00dev) diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c index 0955c941317f..92ff6a72a2bb 100644 --- a/drivers/net/wireless/rt2x00/rt2x00dev.c +++ b/drivers/net/wireless/rt2x00/rt2x00dev.c @@ -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); diff --git a/drivers/net/wireless/rt2x00/rt61pci.c b/drivers/net/wireless/rt2x00/rt61pci.c index 53110b83bf6e..058ef4b19d1d 100644 --- a/drivers/net/wireless/rt2x00/rt61pci.c +++ b/drivers/net/wireless/rt2x00/rt61pci.c @@ -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, ®); rt2x00_set_field32(®, TXRX_CSR9_TSF_TICKING, 1); rt2x00_set_field32(®, 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, ®); 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); } } @@ -2300,22 +2289,24 @@ static void rt61pci_txstatus_tasklet(unsigned long data) { struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data; rt61pci_txdone(rt2x00dev); - rt61pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_TXDONE); + if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags)) + rt61pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_TXDONE); } static void rt61pci_tbtt_tasklet(unsigned long data) { struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data; rt2x00lib_beacondone(rt2x00dev); - rt61pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_BEACON_DONE); + if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags)) + rt61pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_BEACON_DONE); } 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); } @@ -2325,7 +2316,8 @@ static void rt61pci_autowake_tasklet(unsigned long data) rt61pci_wakeup(rt2x00dev); rt2x00pci_register_write(rt2x00dev, M2H_CMD_DONE_CSR, 0xffffffff); - rt61pci_enable_mcu_interrupt(rt2x00dev, MCU_INT_MASK_CSR_TWAKEUP); + if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags)) + rt61pci_enable_mcu_interrupt(rt2x00dev, MCU_INT_MASK_CSR_TWAKEUP); } static irqreturn_t rt61pci_interrupt(int irq, void *dev_instance)