On Tue, 2015-12-15 at 03:26PM -0800, Peter Hurley wrote: > On 12/15/2015 07:41 AM, Sören Brinkmann wrote: > > On Thu, 2015-12-10 at 01:41PM -0800, Peter Hurley wrote: > >> On 12/05/2015 08:39 PM, Soren Brinkmann wrote: > >>> Request_irq() should be _after_ h/w programming, otherwise an > >>> interrupt could be triggered and in-progress before the h/w has been > >>> setup. > >> > >> Slight misunderstanding. My fault; I should have been more explicit. > >> > >> 1. Any setup necessary for the isr not to be confused and misdirect spurious > >> interrupts (or hang) should be before installing the isr with request_irq() > >> None of this code should trigger an interrupt. > >> 2. Clear pending interrupts > >> 3. Install the isr with request_irq() > >> 4. Enable interrupts > > > > Isn't that what the startup function is doing now - more or less. I > > think 3 and 4 are swapped to release the lock and then do the > > request_irq, but I believe that should be OK. > > The startup function configures the HW. Clears the ISR. Enables the > > intended IRQs and then does the request_irq call. > > If the driver enables interrupts before installing the isr with request_irq() > and an interrupt occurs there will the no handler to catch it and EOI the > device. Really? Shouldn't the IRQ be masked in the interrupt controller until everything is in place? Sören -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
