From: Helmut Schaa Date: Sun, 30 Jan 2011 12:20:05 +0000 (+0100) Subject: rt2x00: Convert rt2400pci interrupt handling to use tasklets X-Git-Tag: upstream/snapshot3+hdmi~11215^2~417^2~15 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=bcf3cfd047d599cd0e6758c422bd7a4835c00d4a;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git 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: Helmut Schaa Acked-by: Gertjan van Wingerde 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 cb28e1b..b324917 100644 --- a/drivers/net/wireless/rt2x00/rt2400pci.c +++ b/drivers/net/wireless/rt2x00/rt2400pci.c @@ -645,6 +645,11 @@ 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); @@ -706,6 +711,11 @@ static void rt2400pci_stop_queue(struct data_queue *queue) rt2x00_set_field32(®, CSR14_TBCN, 0); rt2x00_set_field32(®, CSR14_BEACON_GEN, 0); rt2x00pci_register_write(rt2x00dev, CSR14, reg); + + /* + * Wait for possibly running tbtt tasklets. + */ + tasklet_disable(&rt2x00dev->tbtt_tasklet); break; default: break; @@ -964,6 +974,7 @@ static void rt2400pci_toggle_irq(struct rt2x00_dev *rt2x00dev, int mask = (state == STATE_RADIO_IRQ_OFF) || (state == STATE_RADIO_IRQ_OFF_ISR); u32 reg; + unsigned long flags; /* * 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) { rt2x00pci_register_read(rt2x00dev, CSR7, ®); 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. * Non-checked interrupt bits are disabled by default. */ + spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags); + rt2x00pci_register_read(rt2x00dev, CSR8, ®); rt2x00_set_field32(®, CSR8_TBCN_EXPIRE, mask); rt2x00_set_field32(®, CSR8_TXDONE_TXRING, mask); @@ -985,6 +1004,17 @@ static void rt2400pci_toggle_irq(struct rt2x00_dev *rt2x00dev, rt2x00_set_field32(®, CSR8_TXDONE_PRIORING, mask); rt2x00_set_field32(®, CSR8_RXDONE, mask); 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) @@ -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; - u32 reg = rt2x00dev->irqvalue[0]; + unsigned long flags; + u32 reg; /* - * Handle interrupts, walk through all bits - * and run the tasks, the bits are checked in order of - * priority. + * Enable a single interrupt. The interrupt mask register + * access needs locking. */ + spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags); - /* - * 1 - Beacon timer expired interrupt. - */ - if (rt2x00_get_field32(reg, CSR7_TBCN_EXPIRE)) - rt2x00lib_beacondone(rt2x00dev); + rt2x00pci_register_read(rt2x00dev, CSR8, ®); + rt2x00_set_field32(®, irq_field, 0); + rt2x00pci_register_write(rt2x00dev, CSR8, reg); - /* - * 2 - Rx ring done interrupt. - */ - if (rt2x00_get_field32(reg, CSR7_RXDONE)) - rt2x00pci_rxdone(rt2x00dev); + spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags); +} - /* - * 3 - Atim ring transmit done interrupt. - */ - if (rt2x00_get_field32(reg, CSR7_TXDONE_ATIMRING)) - rt2400pci_txdone(rt2x00dev, QID_ATIM); +static void rt2400pci_txstatus_tasklet(unsigned long data) +{ + struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data; + u32 reg; + 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_AC_VO); + rt2400pci_txdone(rt2x00dev, QID_ATIM); + 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)) - rt2400pci_txdone(rt2x00dev, QID_AC_VI); + spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags); - /* Enable interrupts again. */ - rt2x00dev->ops->lib->set_device_state(rt2x00dev, - STATE_RADIO_IRQ_ON_ISR); - return IRQ_HANDLED; + 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_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) { struct rt2x00_dev *rt2x00dev = dev_instance; - u32 reg; + u32 reg, mask; + unsigned long flags; /* * 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)) return IRQ_HANDLED; - /* Store irqvalues for use in the interrupt thread. */ - rt2x00dev->irqvalue[0] = reg; + mask = 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); + + if (rt2x00_get_field32(reg, CSR7_TXDONE_ATIMRING) || + rt2x00_get_field32(reg, CSR7_TXDONE_PRIORING) || + 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); + } - /* Disable interrupts, will be enabled again in the interrupt thread. */ - rt2x00dev->ops->lib->set_device_state(rt2x00dev, - STATE_RADIO_IRQ_OFF_ISR); + /* + * 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); - return IRQ_WAKE_THREAD; + rt2x00pci_register_read(rt2x00dev, CSR8, ®); + 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 = { .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, .initialize = rt2x00pci_initialize, .uninitialize = rt2x00pci_uninitialize,