On Thursday 27 November 2014 23:23:17 Lyra Zhang wrote: > > Yes, I saw this way in other serial drivers. > But, if then, there are two questions for me: > 1. Why did some serial drivers need an UN_SHARED irq? A lot of drivers were written before we had shared IRQs, or were copied from old drivers, or are for hardware that uses edge-triggered interrupts instead of level-triggered interrupts. Only level-triggered interrupts can be shared. > 2. How can we choose a right way? It never hurts to implement a shared interrupt handler. Only if you have no way to find out whether the device triggered the interrupt or not you have to leave out IRQF_SHARED, and then you won't be able to return IRQ_NONE. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
