On 06/25/2013 03:23 AM, Joseph Lo wrote:

This series introduce CPU core power down state for CPU idle. When CPU go
into this state, it saves it's context and needs a proper configuration
in flow controller to power gate the CPU when CPU runs into WFI
instruction. And the CPU also needs to set the IRQ as CPU power down idle
wake up event in flow controller.

To prevent race conditions and ensure proper interrupt routing on
Cortex-A15 CPUs when they are power-gated, add a CPU PM notifier
call-back to reprogram the GIC CPU interface on PM entry. The
GIC CPU interface will be reset back to its normal state by
the common GIC CPU PM exit callback when the CPU wakes up.

This series depends on the patch of "tick:  Fix
tick_broadcast_pending_mask not cleared".

Joseph, I applied all 3 of your patches/series on top of next-20130701,
which does include dependency "tick:  Fix tick_broadcast_pending_mask
not cleared":

* ARM: tegra: cpuidle: use CPUIDLE_FLAG_TIMER_STOP flag
* This series
* ARM: tegra114: add support for system suspend

I find that at least on on Tegra114/Dalmore, CPU hotplug doesn't work
correctly.

If I unplug CPU0, I get an immediate system hang:

root at localhost:~# ./cpuonline.py
echo 0 > /sys/devices/system/cpu/cpu0/online
[   73.555696] IRQ73 no longer affine to CPU0
[   73.561965] CPU0: shutdown

If I adjust my script not to hotplug CPU0, I get a hang when plugging a
CPU back in:

root at localhost:~# ./cpuonline.py
echo 0 > /sys/devices/system/cpu/cpu2/online
[   87.141128] CPU2: shutdown
echo 0 > /sys/devices/system/cpu/cpu1/online
[   89.227597] CPU1: shutdown
echo 0 > /sys/devices/system/cpu/cpu3/online
[   91.253870] CPU3: shutdown
echo 1 > /sys/devices/system/cpu/cpu1/online

or simpler:

root at localhost:~# echo 0 > /sys/devices/system/cpu/cpu1/online
[   80.767825] CPU1: shutdown
root at localhost:~# echo 1 > /sys/devices/system/cpu/cpu1/online

Finally, if I boot afresh and enter system suspend, I see the system
suspend OK, but pressing the power button on either the board itself or
the attached PM342 debug board will not wake the system from sleep.