From: khilman@linaro•org (Kevin Hilman)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2] arm: exynos: Support cluster power off on exynos5420/5800
Date: Thu, 19 Jun 2014 13:34:49 -0700 [thread overview]
Message-ID: <7hy4wsvdsm.fsf@paris.lan> (raw)
In-Reply-To: <1403181617-19743-1-git-send-email-a.kesavan@samsung.com> (Abhilash Kesavan's message of "Thu, 19 Jun 2014 18:10:17 +0530")
Abhilash Kesavan <a.kesavan@samsung•com> writes:
> Turning off a cluster when all 4 cores of the cluster are powered off
> saves power significantly. Powering off the A15 L2 alone gives around
> 100mW in savings. Add support for powering off the A15/A7 clusters on
> exynos5420/5800.
>
> The patch enables specific register bits which ensure that:
> - cluster L2 will be turned on before the first man is powered up.
> - last man will be turned off before the cluster L2 is turned off.
> - core is powered down before powering it up.
>
> Remove the exynos_cluster_power_control function completely as we can
> rely on the above mentioned bits rather than polling the cluster power
> status register.
>
> Signed-off-by: Abhilash Kesavan <a.kesavan@samsung•com>
> Acked-by: Nicolas Pitre <nico@linaro•org>
> ---
> Change in v2:
> Added a macro for the COMMON_OPTION register and used it in the MCPM
> back-end.
>
> The patch is based on Linux-next 20140619. It has been tested on an
> exynos5420-based chromebook using the "/dev/bL_switcher" interface as
> well as the script provided by Nicolas Pitre and Dave Martin [1].
>
> Patch depends on:
> [v2] ARM: EXYNOS: mcpm: Don't rely on firmware's secondary_cpu_start
>
> [1] http://www.spinics.net/lists/linux-samsung-soc/msg31257.html
Tested on exynos5800/Chromebook2 along with the dependency patch and using
the script from Dave and Nico.
Tested-by: Kevin Hilman <khilman@linaro•org>
Kevin
next prev parent reply other threads:[~2014-06-19 20:34 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-18 15:18 [PATCH] arm: exynos: Support cluster power off on exynos5420/5800 Abhilash Kesavan
2014-06-18 15:40 ` Nicolas Pitre
2014-06-19 12:23 ` Abhilash Kesavan
2014-06-19 12:40 ` [PATCH v2] " Abhilash Kesavan
2014-06-19 20:34 ` Kevin Hilman [this message]
2014-06-25 10:14 ` Kukjin Kim
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