On Tue, 27 Jun 2017, Heiko St?bner wrote: > Am Dienstag, 27. Juni 2017, 15:01:32 CEST schrieb Thomas Gleixner: > > The only irq chip function which uses the regmap magic is the > > irq_set_type() callback. Now, I have a hard time to understand (though I'm > > no regmap/pinctrl expert) why that regmap stuff needs to be called in the > > first place. The level and the polarity are programmed via: > > > > writel_relaxed(level, gc->reg_base + GPIO_INTTYPE_LEVEL); > > writel_relaxed(polarity, gc->reg_base + GPIO_INT_POLARITY); > > > > Why needs the regmap machinery to be invoked there? The GPIO is already > > muxed and configured as interrupt, otherwise none of the irq functions > > could be invoked. Hmm? > > That is a safeguard against the pinmux not being set as "gpio" but some other > function, if the irq is requested directly without going through the gpio API. > > But looking at struct irq_chip and also other pinctrl drivers again, it seems > the new [0] irq_request_resources might be the way saner place for this. > Especially as it also prevents the mux-setting from being called more than > once. That'll fail on RT as well because irq_request_resources() is called with irq_desc->lock held and interrupts disabled. irq_request_resources() can probably be called without holding desc->lock, though we need some form of protection against concurrent irq requests/free. I'll have look into that. Thanks, tglx
