From: drake@endlessm.com (Daniel Drake)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 1/2] clk: samsung: exynos4: Enable ARMCLK down feature
Date: Mon, 21 Jul 2014 13:51:59 +0100 [thread overview]
Message-ID: <CAD8Lp45UtZ_aao2ScUUjRq9AfnxGq9GuT24SLzY-koeBfTTDCw@mail.gmail.com> (raw)
In-Reply-To: <1405694193-29643-1-git-send-email-k.kozlowski@samsung.com>
On Fri, Jul 18, 2014 at 3:36 PM, Krzysztof Kozlowski
<k.kozlowski@samsung.com> wrote:
> Enable ARMCLK down feature on all Exynos4 SoCs. The frequency of
> ARMCLK will be reduced upon entering idle mode (WFI or WFE).
>
> The feature behaves like very fast cpufreq ondemand governor. In idle
> mode this reduces energy consumption on full frequency chosen by
> cpufreq governor by approximately:
> - Trats2: 6.5% (153 mA -> 143 mA)
> - Trats: 33.0% (180 mA -> 120 mA)
> - Gear1: 27.0% (180 mA -> 130 mA)
>
> The patch uses simillar settings as Exynos5250 (clk-exynos5250.c),
> except it disables clock up feature and on Exynos4412 ARMCLK down is
> enabled for all 4 cores.
>
> Tested on Trats board (Exynos4210), Trats2 board (Exynos4412) and
> Samsung Gear 1 (Exynos4212).
>
> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Tested on ODROID-U2, seems to be working. I don't have a way of
measuring the power usage, but the system seems as stable as before.
Tested-by: Daniel Drake <drake@endlessm.com>
next prev parent reply other threads:[~2014-07-21 12:51 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-18 14:36 [PATCH v2 1/2] clk: samsung: exynos4: Enable ARMCLK down feature Krzysztof Kozlowski
2014-07-18 14:36 ` [PATCH v2 2/2] clk: samsung: exynos3250: " Krzysztof Kozlowski
2014-07-21 12:51 ` Daniel Drake [this message]
2014-07-23 12:47 ` [PATCH v2 1/2] clk: samsung: exynos4: " Tomasz Figa
2014-07-24 0:18 ` Mike Turquette
2014-07-24 6:42 ` Krzysztof Kozlowski
2014-07-24 9:44 ` Krzysztof Kozlowski
2014-07-25 22:22 ` Mike Turquette
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