[PATCH 1/3] ARM: OMAP: timer: allow gp timer clock-event to be used on both cpus

[Shilimkar, Santosh]

On Fri, Aug 3, 2012 at 4:02 PM, Hiremath, Vaibhav <hvaibhav at ti.com> wrote:
> On Fri, Aug 03, 2012 at 15:18:15, Shilimkar, Santosh wrote:
>> On Fri, Aug 3, 2012 at 3:12 PM, Hiremath, Vaibhav <hvaibhav at ti.com> wrote:
>> > On Fri, Aug 03, 2012 at 15:03:07, Koen Kooi wrote:
>> >>
>> >> Op 3 aug. 2012, om 11:27 heeft "Shilimkar, Santosh" <santosh.shilimkar at ti.com> het volgende geschreven:
>> >>
>> >> > On Fri, Aug 3, 2012 at 2:00 PM, Koen Kooi <koen at dominion.thruhere.net> wrote:
>> >> >>
>> >> >> Op 3 aug. 2012, om 09:21 heeft Koen Kooi <koen at dominion.thruhere.net> het volgende geschreven:
>> >> >>
>> >> >>>
>> >> >>> Op 3 aug. 2012, om 09:16 heeft Daniel Mack <zonque at gmail.com> het volgende geschreven:
>> >> >>>
>> >> >>>> On 30.03.2012 15:27, Santosh Shilimkar wrote:
>> >> >>>>> For coupled cpuidle to work when both cpus are active, it needs a global timer
>> >> >>>>> that can handle events for both cpus.  This timer is used as the broadcast
>> >> >>>>> clock-event when the per-cpu timer hardware stop in low power states.
>> >> >>>>> Set the cpumask of clockevent_gpt to all cpus, set the rating correctly, and
>> >> >>>>> set the irq to allow the clockevent core to determine the affinity of the
>> >> >>>>> timer.
>> >> >>>>
>> >> >>>> These patches made it to mainline now, shortly befor 3.6-rc1, and it
>> >> >>>> breaks boot on my AM33xx board.
>> >> >>>>
>> >> >>>> Once I revert 1/3, the board boots again but crashes with the Ooops
>> >> >>>> below. With the entire series reverted, everything works again as
>> >> >>>> expected. Any idea?
>> >> >>>>
>> >> >>>> The upstream commit ids are
>> >> >>>>
>> >> >>>> 11d6ec2e "ARM: OMAP: timer: allow gp timer clock-event to be used on
>> >> >>>> both cpus"
>> >> >>>> 5b4d5bcc "ARM: OMAP4: CPUidle: add synchronization for coupled idle states"
>> >> >>>> b93d70ae "ARM: OMAP4: CPUidle: Open broadcast clock-event device."
>> >> >>>
>> >> >>> I've had boot problems with cpuidle enabled as well, what happens if you disable it? Is the revert still needed in that case?
>> >> >>
>> >> >> To answer my own question: No, the reverts aren't needed if you disable cpuidle.
>> >> >
>> >> > This is really strange since CPUIDLE code is really OMAP4 specific.
>> >> > obj-$(CONFIG_ARCH_OMAP4)                += cpuidle44xx.o
>> >> >
>> >> > May be omap2plus build some how the code gets executed on AMXX
>> >> >
>> >> > Can you try below and see if the boot with CPUIDLE enabled goes away on
>> >> > AMXX
>> >> >
>> >> > diff --git a/arch/arm/mach-omap2/pm44xx.c b/arch/arm/mach-omap2/pm44xx.c
>> >> > index ea24174..195e756 100644
>> >> > --- a/arch/arm/mach-omap2/pm44xx.c
>> >> > +++ b/arch/arm/mach-omap2/pm44xx.c
>> >> > @@ -147,6 +147,9 @@ int __init omap4_pm_init(void)
>> >> >        struct clockdomain *emif_clkdm, *mpuss_clkdm, *l3_1_clkdm, *l4wkup;
>> >> >        struct clockdomain *ducati_clkdm, *l3_2_clkdm, *l4_per_clkdm;
>> >> >
>> >> > +       if (!cpu_is_omap44xx())
>> >> > +               return -ENODEV;
>> >> > +
>> >> >        if (omap_rev() == OMAP4430_REV_ES1_0) {
>> >> >                WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
>> >> >                return -ENODEV;
>> >>
>> >> That does seem to fix it:
>> >>
>> >> root at beaglebone:~# zcat /proc/config.gz | grep -i cpu_idle
>> >> CONFIG_CPU_IDLE=y
>> >> CONFIG_CPU_IDLE_GOV_LADDER=y
>> >> CONFIG_CPU_IDLE_GOV_MENU=y
>> >> CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED=y
>> >> root at beaglebone:~# zcat /proc/config.gz | grep -i omap4
>> >> CONFIG_ARCH_OMAP4=y
>> >> CONFIG_MACH_OMAP4_PANDA=y
>> >> # CONFIG_OMAP4_ERRATA_I688 is not set
>> >> # CONFIG_KEYBOARD_OMAP4 is not set
>> >> CONFIG_OMAP4_DSS_HDMI=y
>> >>
>> >
>> > This patch is not required, Without this patch is works for me,
>> >
>> Which is good news.Do you have CPUIDLE enabled in your build when you tested
>> it. Note that CPUIDLE is not enabled by-default in omap2plus build and as I see
>> from Koen's email, he did enable it in his testing.
>>
>> Please confirm that 3.6-rc1 boots fine even with CPUIDLE enabled and
>> we don't need
>> the above mentioned patch. If it is not the case, I can post the fix.
>>
>
> Just FYI, I have also tested with CPUIDLE enabled and it worked for me.
>
Thanks Vaibhav for update.

Regards
Santosh