| Message ID | 1448900789-4034-2-git-send-email-tony@atomide.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 11/30/2015 06:26 PM, Tony Lindgren wrote: > We don't need timers right away and initializing them later gives us few > nice things like interrupts and kmalloc. As the timers have a dependency > to the clock framework, we're better off initializing things later rather > than early if things go wrong. And this allows us to make the mux clock > driver needed for system timers into early_platform drivers. > > Note that smp_prepare_cpus() will get called later on during the init so > we just need to local_irq_enable/disable for clocksource_probe(). > > Cc: Felipe Balbi <balbi@ti.com> > Cc: Grygorii Strashko <grygorii.strashko@ti.com> > Cc: Paul Walmsley <paul@pwsan.com> > Cc: Tero Kristo <t-kristo@ti.com> > Signed-off-by: Tony Lindgren <tony@atomide.com> > --- > arch/arm/mach-omap2/timer.c | 46 +++++++++++++++++++++++++++++++++++++++------ > 1 file changed, 40 insertions(+), 6 deletions(-) > > diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c > index b18ebbe..68bf482 100644 > --- a/arch/arm/mach-omap2/timer.c > +++ b/arch/arm/mach-omap2/timer.c > @@ -478,36 +478,56 @@ static void __init __omap_sync32k_timer_init(int clkev_nr, const char *clkev_src > omap2_gp_clockevent_init(clkev_nr, clkev_src, clkev_prop); > > /* Enable the use of clocksource="gp_timer" kernel parameter */ > + local_irq_disable(); > if (use_gptimer_clksrc || gptimer) > omap2_gptimer_clocksource_init(clksrc_nr, clksrc_src, > clksrc_prop); > else > omap2_sync32k_clocksource_init(); > + local_irq_enable(); So, this will be called now after sched_clock_postinit() and to W/A warnings you've added local_irq_disable()/local_irq_enable(). Am I right? Are you sure this is safe?
* Grygorii Strashko <grygorii.strashko@ti.com> [151201 05:53]: > On 11/30/2015 06:26 PM, Tony Lindgren wrote: > > We don't need timers right away and initializing them later gives us few > > nice things like interrupts and kmalloc. As the timers have a dependency > > to the clock framework, we're better off initializing things later rather > > than early if things go wrong. And this allows us to make the mux clock > > driver needed for system timers into early_platform drivers. > > > > Note that smp_prepare_cpus() will get called later on during the init so > > we just need to local_irq_enable/disable for clocksource_probe(). > > > > Cc: Felipe Balbi <balbi@ti.com> > > Cc: Grygorii Strashko <grygorii.strashko@ti.com> > > Cc: Paul Walmsley <paul@pwsan.com> > > Cc: Tero Kristo <t-kristo@ti.com> > > Signed-off-by: Tony Lindgren <tony@atomide.com> > > --- > > arch/arm/mach-omap2/timer.c | 46 +++++++++++++++++++++++++++++++++++++++------ > > 1 file changed, 40 insertions(+), 6 deletions(-) > > > > diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c > > index b18ebbe..68bf482 100644 > > --- a/arch/arm/mach-omap2/timer.c > > +++ b/arch/arm/mach-omap2/timer.c > > @@ -478,36 +478,56 @@ static void __init __omap_sync32k_timer_init(int clkev_nr, const char *clkev_src > > omap2_gp_clockevent_init(clkev_nr, clkev_src, clkev_prop); > > > > /* Enable the use of clocksource="gp_timer" kernel parameter */ > > + local_irq_disable(); > > if (use_gptimer_clksrc || gptimer) > > omap2_gptimer_clocksource_init(clksrc_nr, clksrc_src, > > clksrc_prop); > > else > > omap2_sync32k_clocksource_init(); > > + local_irq_enable(); > > So, this will be called now after sched_clock_postinit() and to W/A warnings > you've added local_irq_disable()/local_irq_enable(). Am I right? > > Are you sure this is safe? Hmm good point, update_sched_clock() is never called again and so it's running on jiffies. We could separate out the sched_clock when the 32k source or a local timer is used. But that does allow initializing the gptimer later on. Anyways, clearly this needs more work. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c index b18ebbe..68bf482 100644 --- a/arch/arm/mach-omap2/timer.c +++ b/arch/arm/mach-omap2/timer.c @@ -478,36 +478,56 @@ static void __init __omap_sync32k_timer_init(int clkev_nr, const char *clkev_src omap2_gp_clockevent_init(clkev_nr, clkev_src, clkev_prop); /* Enable the use of clocksource="gp_timer" kernel parameter */ + local_irq_disable(); if (use_gptimer_clksrc || gptimer) omap2_gptimer_clocksource_init(clksrc_nr, clksrc_src, clksrc_prop); else omap2_sync32k_clocksource_init(); + local_irq_enable(); } -void __init omap_init_time(void) +static void __init omap_init_time_late(void) { __omap_sync32k_timer_init(1, "timer_32k_ck", "ti,timer-alwon", 2, "timer_sys_ck", NULL, false); - if (of_have_populated_dt()) + if (of_have_populated_dt()) { + local_irq_disable(); clocksource_probe(); + local_irq_enable(); + } +} + +void __init omap_init_time(void) +{ + late_time_init = omap_init_time_late; } #if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM43XX) -void __init omap3_secure_sync32k_timer_init(void) +static void __init omap3_secure_sync32k_timer_late_init(void) { __omap_sync32k_timer_init(12, "secure_32k_fck", "ti,timer-secure", 2, "timer_sys_ck", NULL, false); } + +void __init omap3_secure_sync32k_timer_init(void) +{ + late_time_init = omap3_secure_sync32k_timer_late_init; +} #endif /* CONFIG_ARCH_OMAP3 */ #if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM33XX) -void __init omap3_gptimer_timer_init(void) +static void __init omap3_gptimer_late_init(void) { __omap_sync32k_timer_init(2, "timer_sys_ck", NULL, 1, "timer_sys_ck", "ti,timer-alwon", true); } + +void __init omap3_gptimer_timer_init(void) +{ + late_time_init = omap3_gptimer_late_init; +} #endif #if defined(CONFIG_ARCH_OMAP4) || defined(CONFIG_SOC_OMAP5) || \ @@ -518,10 +538,17 @@ static void __init omap4_sync32k_timer_init(void) 2, "sys_clkin_ck", NULL, false); } -void __init omap4_local_timer_init(void) +static void __init omap4_local_timer_late_init(void) { omap4_sync32k_timer_init(); + local_irq_disable(); clocksource_probe(); + local_irq_enable(); +} + +void __init omap4_local_timer_init(void) +{ + late_time_init = omap4_local_timer_late_init; } #endif @@ -640,12 +667,19 @@ sysclk1_based: #endif } -void __init omap5_realtime_timer_init(void) +static void __init omap5_realtime_timer_late_init(void) { omap4_sync32k_timer_init(); realtime_counter_init(); + local_irq_disable(); clocksource_probe(); + local_irq_enable(); +} + +void __init omap5_realtime_timer_init(void) +{ + late_time_init = omap5_realtime_timer_late_init; } #endif /* CONFIG_SOC_OMAP5 || CONFIG_SOC_DRA7XX */
We don't need timers right away and initializing them later gives us few nice things like interrupts and kmalloc. As the timers have a dependency to the clock framework, we're better off initializing things later rather than early if things go wrong. And this allows us to make the mux clock driver needed for system timers into early_platform drivers. Note that smp_prepare_cpus() will get called later on during the init so we just need to local_irq_enable/disable for clocksource_probe(). Cc: Felipe Balbi <balbi@ti.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Paul Walmsley <paul@pwsan.com> Cc: Tero Kristo <t-kristo@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> --- arch/arm/mach-omap2/timer.c | 46 +++++++++++++++++++++++++++++++++++++++------ 1 file changed, 40 insertions(+), 6 deletions(-)