Re: [PATCH v2 2/4] Implement generic time of day clocksource for powerpc machines.
On Fri, Sep 21, 2007 at 02:59:31PM +1000, Paul Mackerras wrote: Daniel Walker writes: I don't think the RTC frequency isn't the same as the timebase? Seems like the RTC only case about seconds at the lowest level. If that's the case then the jiffies clock might be better to use .. The other thing I wonder is if the __USE_RTC boards might have lower level clocks that could be used instead .. It's OK, the RTC isn't what you think it is, it's a pair of CPU-internal registers which count seconds and nanoseconds. On processors with the RTC, tb_ticks_per_sec is initialized to 10. Trust me, this code is OK. :) Indeed.. I'm wondering if we should do a s/rtc/ppc601rtc/ or something. Otherwise people will keep making this mistake and be confused. -- David Gibson| I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH v2 2/4] Implement generic time of day clocksource for powerpc machines.
On Fri, Sep 21, 2007 at 02:52:12PM +1000, Stephen Rothwell wrote: Small comments. Thanks. I think this is redundant as if __USE_RTC() is true, you register clocksource_rtc below. Yup you're right. The #ifdef is redundant since if CONFIG_ISERIES is not set, firmware_has_feature(FW_FEATURE_ISERIES) is constant 0. Ahh okay. I got too fancy for my own good. patch comming. Yours Tony linux.conf.auhttp://linux.conf.au/ || http://lca2008.linux.org.au/ Jan 28 - Feb 02 2008 The Australian Linux Technical Conference! ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH v2 2/4] Implement generic time of day clocksource for powerpc machines.
On Fri, 2007-09-21 at 13:26 +1000, Tony Breeds wrote: + + if (__USE_RTC()) + clock = clocksource_rtc; + else + clock = clocksource_timebase; + + clock-mult = clocksource_hz2mult(tb_ticks_per_sec, clock-shift); I don't think the RTC frequency isn't the same as the timebase? Seems like the RTC only case about seconds at the lowest level. If that's the case then the jiffies clock might be better to use .. The other thing I wonder is if the __USE_RTC boards might have lower level clocks that could be used instead .. Daniel ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH v2 2/4] Implement generic time of day clocksource for powerpc machines.
Daniel Walker writes: I don't think the RTC frequency isn't the same as the timebase? Seems like the RTC only case about seconds at the lowest level. If that's the case then the jiffies clock might be better to use .. The other thing I wonder is if the __USE_RTC boards might have lower level clocks that could be used instead .. It's OK, the RTC isn't what you think it is, it's a pair of CPU-internal registers which count seconds and nanoseconds. On processors with the RTC, tb_ticks_per_sec is initialized to 10. Trust me, this code is OK. :) Paul. ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
