[PATCH v3 0/9] ARM: sunxi: Support cpufreq on sun[457]i

Maxime Ripard maxime.ripard at free-electrons.com
Mon Jan 12 01:10:20 PST 2015

On Mon, Jan 12, 2015 at 12:34:00PM +0800, Chen-Yu Tsai wrote:
> Hi,
> This is v3 of the cpufreq support series for sunxi. The series has been
> rebased onto the latest sunxi-next. I've dropped all the patches Maxime
> merged. This includes "ARM: sunxi: Register cpufreq-dt for sun[45678]i"
> which was merged but not published yet.
> Individual changes since v2 are listed within each patch.
> Original cover letter follows:
> This series adds support cpufreq support for sun[457]i using cpufreq-dt.
> This also supports passive cpu cooling (thermal throttling) using thermal
> zones with the temperature sensor in the SoC.
> The operating points for the supported platforms were taken from the
> linux-sunxi FEX files repository. The majority of boards use the same
> settings. Only with sun7i do we see slight variations, either disabling
> some frequencies, or bumping up the voltage a bit. In either case this
> can be done by limiting the constraints for the supply regulator, or 
> overriding the OPP table in the board dts file.
> On sun7i, there is an additional operating point not found in the FEX
> files, 960 MHz @ 1.4V, which is the full speed setting in both u-boot-sunxi
> and mainline u-boot.
> The series has been tested on the 4 boards I have. With cpufreq active,
> the effects are visible as a decrease in SoC internal temperature.
> Stability for the operating points has been tested using:
>   http://linux-sunxi.org/Hardware_Reliability_Tests#Reliability_of_cpufreq_voltage.2Ffrequency_settings
> More real world usage feedback is appreciated. Thermal throttling hasn't
> been tested much, due to not being able to generate enough load without
> the GPU for the SoC to heat up. Also on sun4i, the temperature sensor
> still hasn't been calibrated, so the readings are highly inaccurate.

Applied 2, 3, 6 and 8.

There's still some discussions about the boards regulators, that apply
to all of them, even though I commented on one in particular.


Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: Digital signature
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20150112/85077dc8/attachment.sig>

More information about the linux-arm-kernel mailing list