[PATCH v5 0/5] ARM: EXYNOS: cpuidle: fix AFTR mode on boards with secure firmware enabled

On 05.08.2014 16:03, Daniel Lezcano wrote:

On 08/05/2014 03:34 PM, Bartlomiej Zolnierkiewicz wrote:

quoted

Hi,

This patch series adds support for AFTR idle mode on boards with
secure firmware enabled and allows EXYNOS cpuidle driver usage on
Exynos4x12 SoCs.

It has been tested on Trats2 board (using Exynos4412 SoC with secure
firmware enabled) on which AFTR mode reduces power consumption by ~12%
when EXYNOS cpuidle driver is enabled (in both cases the default
exynos_defconfig config is used and CPU1-3 are offlined).

As a sidenote:

On my odroid-U2:
  * 4 cpus online -> 130 mA
  * 3 cpus online -> 164 mA
  * 2 cpus online -> 160 mA
  * 1 cpu online  -> 157 mA

So were are consuming more when there are unplugged cpu ... any ideas ?

On which tree are you testing? Current next has ARMCLK down feature 
enabled. ARMCLK down may stop working after hotunplugging CPU:
http://www.spinics.net/lists/arm-kernel/msg352890.html

That was observed especially on Exynos4212 where ARMCLK down stops 
working permanently. On Trats2 (Exynos4412) the clock down stopped only 
a for short period after disabling CPU.

Best regards,
Krzysztof