On Wed, Mar 15, 2017 at 02:12:39PM +0100, Linus Walleij wrote: > On Mon, Mar 13, 2017 at 7:38 PM, John Keeping <john@xxxxxxxxxxxx> wrote: > > > As described in Documentation/gpio/driver.txt, we should not be using > > sleepable APIs in the irqchip implementation. Since this includes the > > regmap API, this patch series ends up moving the mux setup for IRQs into > > an irq_bus_sync_unlock() handler which may result in the IRQ being > > configured before the port has been muxed as a GPIO. > > > > I've marked the series as RFC because I'm not sure if this is the best > > way to accomplish this or if there is another approach that is cleaner. > > Also, the first patch may not be correct on RK3399 because I originally > > wrote the patch for RK3288 on top of v4.4 where all drive updates only > > affect a single register. We don't need locking in this case because > > regmap_update_bits() takes a lock on the regmap internally, but if these > > two registers need to be updated atomically then another lock will > > be required here - slock cannot be used if it is converted to a raw > > spinlock since with full RT preemption the regmap's spinlock may sleep. > > Nice work! It all looks good to me, let's see what Heiko says. > > Please keep Julia Cartwright on the CC for this patch series, she is > doing some coccinelle-based rewrites to use raw spinlocks as we > speak, and she knows this stuff. > > She has not targeted the Rockchip driver yet, I guess because of > its complexity. I haven't really given much thought to how we might generically solve raw_spinlock problems for those drivers which make of irq_chip_generic just yet. I don't imagine it would be too difficult, just more work. Thanks for the CC. Julia
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