On 01/31/13 17:32, Santosh Shilimkar wrote: > The timekeeping doesn't depend on HZ value in presence of fine grained > clocksource and hence there should not be any time drift because of HZ > value which was chosen to be divisor of 32768. > > OMAP has been using HZ = 128 value to avoid any time drift issues > because of 32768 HZ clock. But with various measurements performed > with HZ = 100, no time drift is observed and it also proves the > point about HZ not having impact on time keeping on OMAP. Great! I had the same patch in my tree already for several months, but I was afraid to send it as I had no time to test it thoroughly. These kind of things are always scary to send without proper testing... Thank you very much for testing and sending this out! > > Very informative thread on this topic is here: > https://lkml.org/lkml/2013/1/29/435 > > Special thanks to John Stulz, Arnd Bergmann and Russell King for their > valuable suggestions. > > Cc: Arnd Bergmann <arnd@xxxxxxxx> > Cc: Russell King <linux@xxxxxxxxxxxxxxxx> > Cc: John Stultz <john.stultz@xxxxxxxxxx> > Cc: Tony Lindgren <tony@xxxxxxxxxxx> If it still not too late: Acked-by: Igor Grinberg <grinberg@xxxxxxxxxxxxxx> > > Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx> > Tested-by: Lokesh Vutla <lokeshvutla@xxxxxx> > --- > arch/arm/Kconfig | 1 - > arch/arm/plat-omap/Kconfig | 9 --------- > arch/arm/plat-omap/include/plat/timex.h | 8 -------- > 3 files changed, 18 deletions(-) > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index b35b27f..5493164 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -1648,7 +1648,6 @@ config HZ > int > default 200 if ARCH_EBSA110 || ARCH_S3C24XX || ARCH_S5P64X0 || \ > ARCH_S5PV210 || ARCH_EXYNOS4 > - default OMAP_32K_TIMER_HZ if ARCH_OMAP && OMAP_32K_TIMER > default AT91_TIMER_HZ if ARCH_AT91 > default SHMOBILE_TIMER_HZ if ARCH_SHMOBILE > default 100 > diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig > index 67c859c..ce66eb9 100644 > --- a/arch/arm/plat-omap/Kconfig > +++ b/arch/arm/plat-omap/Kconfig > @@ -147,15 +147,6 @@ config OMAP3_L2_AUX_SECURE_SERVICE_SET_ID > help > PPA routine service ID for setting L2 auxiliary control register. > > -config OMAP_32K_TIMER_HZ > - int "Kernel internal timer frequency for 32KHz timer" > - range 32 1024 > - depends on OMAP_32K_TIMER > - default "128" > - help > - Kernel internal timer frequency should be a divisor of 32768, > - such as 64 or 128. > - > config OMAP_DM_TIMER > bool "Use dual-mode timer" > depends on ARCH_OMAP16XX || ARCH_OMAP2PLUS > diff --git a/arch/arm/plat-omap/include/plat/timex.h b/arch/arm/plat-omap/include/plat/timex.h > index 6d35767..e27d2da 100644 > --- a/arch/arm/plat-omap/include/plat/timex.h > +++ b/arch/arm/plat-omap/include/plat/timex.h > @@ -28,14 +28,6 @@ > #if !defined(__ASM_ARCH_OMAP_TIMEX_H) > #define __ASM_ARCH_OMAP_TIMEX_H > > -/* > - * OMAP 32KHz timer updates time one jiffie at a time from a secondary timer, > - * and that's why the CLOCK_TICK_RATE is not 32768. > - */ > -#ifdef CONFIG_OMAP_32K_TIMER > -#define CLOCK_TICK_RATE (CONFIG_OMAP_32K_TIMER_HZ) > -#else > #define CLOCK_TICK_RATE (HZ * 100000UL) > -#endif > > #endif /* __ASM_ARCH_OMAP_TIMEX_H */ > -- Regards, Igor. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
