Linux中斷的沿觸發和電平觸發

* handle_edge_irq - edge type IRQ handler
* @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* Interrupt occures on the falling and/or rising edge of a hardware
* signal. The occurence is latched into the irq controller hardware
* and must be acked in order to be reenabled. After the ack another
* interrupt can happen on the same source even before the first one
* is handled by the assosiacted event handler. If this happens it
* might be necessary to disable (mask) the interrupt depending on the
* controller hardware. This requires to reenable the interrupt inside
* of the loop which handles the interrupts which have arrived while
* the handler was running. If all pending interrupts are handled, the
* loop is left.
*/

* handle_level_irq - Level type irq handler
* @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* Level type interrupts are active as long as the hardware line has
* the active level. This may require to mask the interrupt and unmask
* it after the associated handler has acknowledged the device, so the
* interrupt line is back to inactive.
*/

//

handle_level_irqirqreturn_t action_ret
spin_lockmask_ack_irq
desckstat_incr_irqs_this_cpu
* If its disabled or no action available
* keep it masked and get out of here
*/action 
descspin_unlock
action_ret note_interrupt
spin_lockdesc
descdescout_unlockspin_unlockEXPORT_SYMBOL_GPL
handle_edge_irqspin_lock
desc
* If we're currently running this IRQ, or its disabled,
* we shouldn't process the IRQ. Mark it pending, handle
* the necessary masking and go out
*/descmask_ack_irqkstat_incr_irqs_this_cpu
desc
desc
irqreturn_t action_ret
desc
* When another irq arrived while we were handling
* one, we could have masked the irq.
* Renable it, if it was not disabled in meantime.
*/descdesc
descspin_unlockaction_ret note_interruptspin_lock

descout_unlockspin_unlock