Re: [RESEND PATCH v5 3/5] acerhdf: Use bang-bang thermal governor

Peter Feuerer
2014-12-04T07:22:26Z

Hi again,

Peter Feuerer writes:

> Hi Darren,
>
> thank you very much for your reply.
>
>
> Darren Hart writes:
>
>> On Fri, Nov 28, 2014 at 03:20:50PM +0100, Peter Feuerer wrote:
>>> acerhdf has been doing an on-off fan control using hysteresis by
>>> post-manipulating the outcome of thermal subsystem trip point handling.
>>> This patch enables acerhdf to use the bang-bang governor, which is
>>> intended for on-off controlled fans.
>>>
>>> Cc: platform-driver-x86@vger.kernel.org
>>> Cc: Darren Hart <dvhart@infradead.org>
>>> Cc: Andrew Morton <akpm@linux-foundation.org>
>>> CC: Zhang Rui <rui.zhang@intel.com>
>>> Cc: Andreas Mohr <andi@lisas.de>
>>> Cc: Javi Merino <javi.merino@arm.com>
>>> Acked-and-tested-by: Borislav Petkov <bp@suse.de>
>>> Signed-off-by: Peter Feuerer <peter@piie.net>
>>> ---
>>> drivers/platform/x86/Kconfig | 3 ++-
>>> drivers/platform/x86/acerhdf.c | 36 +++++++++++++++++++++++++++++++-----
>>> 2 files changed, 33 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
>>> index a2eabe6..c173266 100644
>>> --- a/drivers/platform/x86/Kconfig
>>> +++ b/drivers/platform/x86/Kconfig
>>> @@ -38,7 +38,8 @@ config ACER_WMI
>>>
>>> config ACERHDF
>>> tristate "Acer Aspire One temperature and fan driver"
>>> - depends on THERMAL && ACPI
>>> + select THERMAL_GOV_BANG_BANG
>>
>> So we use select sparingly as it does implicit things.
>>
>> I checked the THERMAL_GOV_BANG_BANG Kconfig entry, and the help says acerhdf
>> already depends on it (which it doesn't appear to). Any particular reason to add
>> select here instead of adding it as a depends.
>>
>> Why did you drop THERMAL?
>
> I had it like this in my first version of patches:
> + depends on THERMAL && ACPI && THERMAL_GOV_BANG_BANG
>
> But after some discussion with lkml community we ended up with the select
> line and dropped THERMAL dependency, as it is implied by
> THEMAL_GOV_BANG_BANG. I'm not so experienced with Kconfig, so I must rely
> on the statements of the community in this case.

Just found the link about this discussion I had with Rui and Boris:
http://linux-kernel.2935.n7.nabble.com/PATCH-0-4-acerhdf-thermal-adding-new-models-and-appropriate-governor-tp848572p908256.html

[...]

--
kind regards,
--peter;