[PATCH v8] ARM: EXYNOS: Use MCPM call-backs to support S2R on Exynos5420

[Abhilash Kesavan]

Hi Javier,

On Mon, Oct 6, 2014 at 1:45 PM, Javier Martinez Canillas
<javier at dowhile0.org> wrote:
> Hello Abhilash,
>
> On Mon, Oct 6, 2014 at 5:40 AM, Abhilash Kesavan
> <kesavan.abhilash at gmail.com> wrote:
>> Hi Javier,
>>
>> [...]
>>
>>> diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c
>>> index adb36a8..222aa3c 100644
>>> --- a/arch/arm/mach-exynos/platsmp.c
>>> +++ b/arch/arm/mach-exynos/platsmp.c
>>> @@ -137,6 +137,18 @@ void exynos_cpu_power_down(int cpu)
>>>   */
>>>  void exynos_cpu_power_up(int cpu)
>>>  {
>>> +       if (cpu == 0 && (of_machine_is_compatible("samsung,exynos5420") ||
>>> +               of_machine_is_compatible("samsung,exynos5800"))) {
>>> +               /*
>>> +                * Bypass power down for CPU0 during suspend. Check for
>>> +                * the SYS_PWR_REG value to decide if we are suspending
>>> +                * the system.
>>> +                */
>>> +               int val = __raw_readl(pmu_base_addr +
>>> +                               EXYNOS5_ARM_CORE0_SYS_PWR_REG);
>>> +               if (!(val & S5P_CORE_LOCAL_PWR_EN))
>>> +                       return;
>>> +       }
>>>         pmu_raw_writel(S5P_CORE_LOCAL_PWR_EN,
>>>                         EXYNOS_ARM_CORE_CONFIGURATION(cpu));
>>>  }
>>
>> The above block of code should be in exynos_cpu_power_down(). Can you
>> re-test s2r after modifying it ? I have to convert a __raw_readl to
>> pmu_raw_readl in this patch as well. Once Vikas re-works the base s2r
>> patch I will re-post a v9.
>>
>
> Thanks, for the information but unfortunately even after this change I
> still have the issue reported in [0]. I also removed the lines from
> exynos5420_pm_resume() that you asked Vikash [1].

I have just tested this on the 5420 that I have and it resumes fine.
The difference could be in the bootloader we are using. I'll send out
details of my current setup so that you can cross-check if everything
is the same.
>
> Which __raw_readl() you had to convert? That is only for consistency
> right? Since I see that the __raw_readl() calls are using
> pmu_base_addr + offset so it seems to be correct.

Yes, it is only for consistency. It should not cause any issues if you
leave it as it is.

>
> I'll test again once you both re-spin your patches then.

OK.

Regards,
Abhilash
>
>> Regards,
>> Abhilash
>
> Best regards,
> Javier
>
> [0]: http://www.spinics.net/lists/arm-kernel/msg367615.html
> [1]: http://www.spinics.net/lists/linux-samsung-soc/msg37561.html