On Tue, Jul 21, 2009 at 01:49:33PM +0100, Mark Brown wrote: > On Tue, Jul 21, 2009 at 06:00:07PM +0530, Trilok Soni wrote: > > > Hopefully, this thread can give all details about threaded irq discussion. > > > http://lkml.org/lkml/2009/2/27/255 > > Yes, I'm aware of that - I read it at the time. It seemed to peter out > without any satisfactory solution, unfortunately. There's two separate > issues here: > > - Ordinary devices on interrupt driven or slow buses like I2C. These > need something along the lines of request_threaded_irq() that's allows > them to schedule the main IRQ handler outside hardirq context so > that they can interact with the device. They need to do something in > hardirq context to disable the interrupt if it's level triggered but > most of the time the only option they've got is to disable the IRQ > and reenable it when the worker thread is done. This is the issue > here. > > My immediate thought when I noticed this was that we should probably > fix request_threaded_irq() so that it's useful for them; I'd been > intending to do some digging and try to understand why it is > currently implemented as it is. > > - Multi-function devices like the twl4030 which have an interrupt > controller on them and would like to expose that interrupt controller > via the generic IRQ subsystem. This was a large part of the > discussion in the thread above is a much trickier problem. > > I've added the folks from Samsung posting the MELFAS MCS-5000 driver to > the thread since they're running into the same issue. > Let's also add Thomas and David since I believe they worked on the feature. >From my part I would like to have the threaded IRQ available to all drivers since it seens to be hanlding driver shutdown cleanly and without races which is a big plus for me since very few drivers get it right. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
