Re: [PATCH v2 0/7] Add CPU Frequency scaling support on Armada 37xx

[Gregory CLEMENT <gregory.clement@free-electrons.com>]

Hi Rafael,
 
 On jeu., déc. 07 2017, "Rafael J. Wysocki" <rjw@rjwysocki.net> wrote:

> On Thursday, December 7, 2017 2:56:09 PM CET Gregory CLEMENT wrote:
>> Hi,
>> 
>> This is the second version of a series adding the CPU Frequency
>> support on Armada 37xx using DVFS. It is based on the initial work of
>> Evan Wang and Victor Gu.
>> 
>> The main change since the first version was a bug fixed in the
>> "cpufreq: Add DVFS support for Armada 37xx" patch which was preventing
>> to register the opp. An other noticeable change is the 4th patch which
>> is new adding the use of dev_pm_opp_remove and removing an comment
>> became wrong. The other changes are described in the change log.
>> 
>> DVFS control is done by a set of registers from the North Bridge Power
>> Management block. The binding for this block is documented in patch 1.
>> 
>> While adding a new cpufreq driver I found that the Kconfig and
>> Makefile were no more in order, so it is fixed by patch 2 and 3.
>> 
>> The 5th patch is just about updating the MAINTAINERS file with the new
>> driver.
>> 
>> The next patch is the real purpose of the series. The main goal of
>> this driver is to setup the CPU load level in the hardware to
>> associate them to CPU frequencies and register a standard cpufreq
>> driver. Note that the hardware also capable of doing AVS (Adaptive
>> Voltage Scaling), by associating a voltage on each level beside the
>> CPU frequency. However, this support is not yet ready, so it is not
>> part of this series.
>> 
>> Finally, the last patch is for arm-soc the arm-soc subsystem through
>> mvebu and update the device tree to support the CPU frequency scaling.
>> 
>> An update on the CPU clock driver is needed in order to take into
>> account the DVFS setting. It's the purpose of an other series already
>> sent, but is no dependencies between the series (for building or at
>> runtime).
>> 
>> Thanks,
>> 
>> Gregory
>> 
>> Changelog:
>> 
>> v1 -> v2:
>> 
>>  - using syscon instead of nb_pm for the binding of the North bridge
>>    power management unit: reported by Rob Herring
>> 
>>  - fix sorting inside the big LITTLE section for the Kconfig: reported
>>    by Viresh Kumar
>> 
>>  - fix the bogus freq calculation in armada37xx_cpufreq_driver_init,
>>    bug reported by Andre Heider
>> 
>>  - use dev_pm_opp_remove() on the previous opp if dev_pm_opp_add()
>>    failed, reported by Viresh Kumar
>> 
>>  - add the Tested-by flag from Andre Heider on "cpufreq: Add DVFS
>>    support for Armada 37xx" patch
>> 
>> Gregory CLEMENT (7):
>>   dt-bindings: marvell: Add documentation for the North Bridge PM on
>>     Armada 37xx
>>   cpufreq: ARM: sort the Kconfig menu
>>   cpufreq: sort the drivers in ARM part
>>   cpufreq: mvebu: Use dev_pm_opp_remove()
>>   MAINTAINERS: add new entries for Armada 37xx cpufreq driver
>>   cpufreq: Add DVFS support for Armada 37xx
>>   arm64: dts: marvell: armada-37xx: add nodes allowing cpufreq support
>> 
>>  .../bindings/arm/marvell/armada-37xx.txt           |  19 ++
>>  MAINTAINERS                                        |   1 +
>>  arch/arm64/boot/dts/marvell/armada-372x.dtsi       |   1 +
>>  arch/arm64/boot/dts/marvell/armada-37xx.dtsi       |   7 +
>>  drivers/cpufreq/Kconfig.arm                        |  89 ++++----
>>  drivers/cpufreq/Makefile                           |   9 +-
>>  drivers/cpufreq/armada-37xx-cpufreq.c              | 241 +++++++++++++++++++++
>>  drivers/cpufreq/mvebu-cpufreq.c                    |  11 +-
>>  8 files changed, 327 insertions(+), 51 deletions(-)
>>  create mode 100644 drivers/cpufreq/armada-37xx-cpufreq.c
>
> I'd like you to split patches [2-3/7] off this series as they aren't
> exactly related to the other changes in it.

Actually the patch 6 depend on patch 2 and 3. To be more precise they
modify the same area inside the files drivers/cpufreq/Kconfig.arm and
drivers/cpufreq/Makefile.

So if I move them in an other series then there could be some merge
conflicts.

Gregory

>
> Thanks,
> Rafael
>

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com