Geert Uytterhoeven <ge...@linux-m68k.org> writes: > On Thu, Apr 23, 2015 at 4:44 PM, Alan Stern <st...@rowland.harvard.edu> wrote: >> On Thu, 23 Apr 2015, Geert Uytterhoeven wrote: >>> >> I'm afraid you can't call pm_runtime_get_sync() from these methods, as >>> >> they may be called from interrupt context. >>> > >>> > Ouch. I know the clock framework has prepare/enable separated with >>> > context, but with the irqchip callbacks I suppose no such separation >>> >>> It's not the clock operations, but the pm_runtime operations that cannot be >>> called from interrupt context. >> >> In fact the pm_runtime operations _can_ be called from interrupt >> context, provided the driver has first invoked pm_runtime_irq_safe(). >> Of course, this requires that none of the runtime-PM callback routines >> ever sleep or perform a blocking operation. >> >> This is all explained in Documentation/power/runtime_pm.txt (search for >> "irq_safe"). > > Perhaps that can help. We'll have to give it a try... > > I've always found this a bit strange when PM Domains are involved: > pm_runtime_irq_safe(dev) applies to device dev, while the actual callbacks > belong to the PM Domain code (the device's driver doesn't have any).
Currently PM domains don't support IRQ-safe devices very well. Any irq_safe devices will prevent the entire PM domain from ever powering off. There is some on-going work for this but it requires reworking the genpd locking a bit. Kevin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
