| Message ID | 1450125246-17249-2-git-send-email-grygorii.strashko@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
* Grygorii Strashko <grygorii.strashko@ti.com> [151214 12:35]: > System will misbehave in the following case: > - AM43XX only build (UP); > - CONFIG_CPU_IDLE=y > - ARM TWD timer enabled and selected as clockevent device. > > In the above case, It's expected that broadcast timer will be used as > backup timer when CPUIdle will put MPU in low power states where ARM > TWD will stop and lose its context. But, the CONFIG_SMP might not be > selected when kernel is built for AM43XX SoC only and, as result, > GENERIC_CLOCKEVENTS_BROADCAST option will not be selected also. This > will break CPUIdle and System will stuck in low power states. > > Hence, fix it by selecting GENERIC_CLOCKEVENTS_BROADCAST option for > AM43XX SoCs always and add empty tick_broadcast() function > implementation - no need to send any IPI on UP. After this change > timer1 will be selected as broadcast timer the same way as for SMP, > and CPUIdle will work properly. I've applied both of these into omap-for-v4.4/fixes because of the description above. Regards, Tony > > Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> > --- > arch/arm/mach-omap2/Kconfig | 1 + > arch/arm/mach-omap2/timer.c | 6 ++++++ > 2 files changed, 7 insertions(+) > > diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig > index 4b4371d..32a0086 100644 > --- a/arch/arm/mach-omap2/Kconfig > +++ b/arch/arm/mach-omap2/Kconfig > @@ -65,6 +65,7 @@ config SOC_AM43XX > select MACH_OMAP_GENERIC > select MIGHT_HAVE_CACHE_L2X0 > select HAVE_ARM_SCU > + select GENERIC_CLOCKEVENTS_BROADCAST > > config SOC_DRA7XX > bool "TI DRA7XX" > diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c > index 3bfde44..f34a809 100644 > --- a/arch/arm/mach-omap2/timer.c > +++ b/arch/arm/mach-omap2/timer.c > @@ -320,6 +320,12 @@ static int __init omap_dm_timer_init_one(struct omap_dm_timer *timer, > return r; > } > > +#if !defined(CONFIG_SMP) && defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) > +void tick_broadcast(const struct cpumask *mask) > +{ > +} > +#endif > + > static void __init omap2_gp_clockevent_init(int gptimer_id, > const char *fck_source, > const char *property) > -- > 2.6.4 >
diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig index 4b4371d..32a0086 100644 --- a/arch/arm/mach-omap2/Kconfig +++ b/arch/arm/mach-omap2/Kconfig @@ -65,6 +65,7 @@ config SOC_AM43XX select MACH_OMAP_GENERIC select MIGHT_HAVE_CACHE_L2X0 select HAVE_ARM_SCU + select GENERIC_CLOCKEVENTS_BROADCAST config SOC_DRA7XX bool "TI DRA7XX" diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c index 3bfde44..f34a809 100644 --- a/arch/arm/mach-omap2/timer.c +++ b/arch/arm/mach-omap2/timer.c @@ -320,6 +320,12 @@ static int __init omap_dm_timer_init_one(struct omap_dm_timer *timer, return r; } +#if !defined(CONFIG_SMP) && defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) +void tick_broadcast(const struct cpumask *mask) +{ +} +#endif + static void __init omap2_gp_clockevent_init(int gptimer_id, const char *fck_source, const char *property)
System will misbehave in the following case: - AM43XX only build (UP); - CONFIG_CPU_IDLE=y - ARM TWD timer enabled and selected as clockevent device. In the above case, It's expected that broadcast timer will be used as backup timer when CPUIdle will put MPU in low power states where ARM TWD will stop and lose its context. But, the CONFIG_SMP might not be selected when kernel is built for AM43XX SoC only and, as result, GENERIC_CLOCKEVENTS_BROADCAST option will not be selected also. This will break CPUIdle and System will stuck in low power states. Hence, fix it by selecting GENERIC_CLOCKEVENTS_BROADCAST option for AM43XX SoCs always and add empty tick_broadcast() function implementation - no need to send any IPI on UP. After this change timer1 will be selected as broadcast timer the same way as for SMP, and CPUIdle will work properly. Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> --- arch/arm/mach-omap2/Kconfig | 1 + arch/arm/mach-omap2/timer.c | 6 ++++++ 2 files changed, 7 insertions(+)