[PATCH v9 0/2] Adds PMU and S2R support for exynos5420

[Abhilash Kesavan]

Hi Kevin,

On Fri, Oct 10, 2014 at 4:29 AM, Kevin Hilman <khilman at kernel.org> wrote:
> Kevin Hilman <khilman at kernel.org> writes:
>
> [...]
>
>> Trying $SUBJECT series on top of kukjin's for-next is working fine, but
>> I'm still not able to make it work on linux-next, with or without the
>> CLK_IGNORE_UNUSED patch.
>
> Nevermind, turns out I didn't apply the CLK_IGNORE_UNUSED PATCH.  If I
> actually apply it, I have it working on top of linux-next.  However, it
> seems to have some issues with the nonboot CPUs resuming:
>
> [   11.319833] Enabling non-boot CPUs ...
> [   12.319134] CPU1: failed to come online
> [   12.319235] Error taking CPU1 up: -5
> [   13.319137] CPU2: failed to come online
> [   13.319209] Error taking CPU2 up: -5
> [   14.319133] CPU3: failed to come online
> [   14.319224] Error taking CPU3 up: -5
>
> Are you guys seeing all the non-boot CPUs coming up?  They fail to come
> online, but the /sys/devices/.../cpu?/online reports that they are
> online, which means the next attempt to hotplug them will probably BUG().
>
> Also, If I turn off the switcher (enabled by default exynos_defconfig),
> resume still has problems bringing all the nonboot CPUs online, and then
> has a bunch of I2C errors[1].
>
> And one more..., if I try enabling CPUidle[1] with exynos_defconfig, S2R
> causes a reboot (seems to be on resume.)

I tested S2R on my Peach-Pi (Exynos5800) on linux-next-20141009. My tree has:

a57db95 TEMP: Use CLK_IGNORE_UNUSED for aclk200_disp1
18158ac ARM: EXYNOS: Use MCPM call-backs to support S2R on Exynos5420
d86cb2d ARM: exynos5: Add Suspend-to-RAM support for 5420
93f1b7c ARM: exynos5: Add PMU support for 5420
8dcc2db ARM: EXYNOS: Move PMU specific definitions from common.h
493a16a ARM: EXYNOS: Add platform driver support for Exynos PMU
64e73fb mfd: syscon: Decouple syscon interface from platform devices
af7b574 Add linux-next specific files for 20141009
4658bc0 Merge branch 'akpm/master'
9784a19 mm: add strictlimit knob

I have tested the following scenarios using exynos_defconfig with
CONFIG_COMMON_CLK_MAX77802 enabled:

1) CONFIG_BIG_LITTLE enabled (default in exynos_defconfig)
2) CONFIG_BIG_LITTLE disabled
3) CONFIG_ARM_BIG_LITTLE_CPUIDLE enabled

In all 3 cases the secondary cores as well as the system resume fine.
Can you please confirm if your kernel has a similar configuration ?

Regards,
Abhilash