On Tue, Nov 01, 2016 at 01:57:05PM -0700, Vineet Gupta wrote: > Hi Daniel, > > On 11/01/2016 01:42 PM, Daniel Lezcano wrote: > > Please stay consistent with the rest of the Kconfig. > > > > config ARC_TIMER_RTC > > bool "64-bit cycle counter in HS38 cores" if COMPILE_TEST > > select CLKSRC_OF > > help > > This counter provides 64-bit resolution vs. the 32-bit TIMER1. > > It is implemented inside the core thus can't be used in SMP systems. > > > > config ARC_TIMER_GFRC > > bool "64-bit cycle counter in ARConnect block in HS38x cores" if COMPILE_TEST > > select CLKSRC_OF > > help > > This counter can be used as clocksource in SMP HS38 SoCs. > > It sits outside the core thus can be used in SMP systems > > > > Yes I did so already :-) Although I also added a default y if ARC to both, but as > you say that is better done in ARC Kconfig. > > > Then in the ARC's Kconfig you select ARC_TIMER_RTC or ARC_TIMER_GFRC depending > > it is SMP or not. > > > > One question: > > > > Why ARC_TIMER_RTC can't be used in a SMP system ? Doesn't have each core its > > own clocksource ? It seems you are assuming a clocksource can be used on SMP > > only if the clocksource is unique and shared across the cores. > As now the clksrc-probe is correctly handling the errors, if the rtc and the gfrc are both defined in the DT, you can fail to init the rtc one with a simple test in the init function: if (IS_DEFINED(CONFIG_SMP)) return -EINVAL; So, you can inconditionaly compile in both RTC and GFRC, no ? That would be cleaner and prevent a different kernel config.
