On Tue, 27 Jun 2017, Thomas Gleixner wrote: > That aside, looking at the commit which caused this discussion: > > 88bb94216f59e pinctrl: rockchip: avoid hardirq-unsafe functions in irq_chip > > I assume (the changelog lacks details) that the patch want's to avoid a > might sleep splat from the irq callbacks caused by the regmap spinlock, > which gets converted into a sleeping lock on RT. It does this by abusing > the irq_bus_lock() mechanism, which is wrong to begin with. > > 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 said, the commit should be reverted and the issue needs to analyzed proper. We still need the RCU -> SCRU conversion, but that's a different problem. Thanks, tglx
