[PATCH] ARM: multi_v7_defconfig: major refresh

[olof@lixom.net (Olof Johansson)]

On Fri, Aug 1, 2014 at 4:01 AM, Jon Medhurst (Tixy) <tixy@linaro.org> wrote:
> On Fri, 2014-08-01 at 11:26 +0100, Sudeep Holla wrote:
>>
>> On 22/07/14 19:01, Olof Johansson wrote:
>> > This is a major refresh of the multi_v7_defconfig:
>> >
>> > - Bring over a bunch of Samsung drivers to make ODROID-U3 and Chromebooks usable
>> >   * Enable big.LITTLE
>> >   * MCPM
>> [...]
>
>> > +CONFIG_BIG_LITTLE=y
>> > +CONFIG_BL_SWITCHER=y
>>
>> IIUC, this will enable switcher code by default. I am not sure if this
>> is intentional ? E.g.: After this I can have only 2 active cpus instead
>> of 5 on my Vexpress TC2 platform.
>>
>> IMO we can keep this enabled by default in the build, but disabled
>> by default on boot.
>
> TC2 has a big.LITTLE processor and the switcher is the only mainlined
> way of making any kind of proper use of big.LITTLE, so why not have it
> enabled by default?

+1.

>
>>  One way to achieve this:
>> (There's sysfs to re-enable it runtime)
>
> The opposite is also true, if you don't want the switcher enabled you
> can disable it by the same method after boot ;-)
>
>> -->8
>> diff --git a/arch/arm/common/bL_switcher.c b/arch/arm/common/bL_switcher.c
>> index 490f3dced749..f4c36e70166a 100644
>> --- a/arch/arm/common/bL_switcher.c
>> +++ b/arch/arm/common/bL_switcher.c
>> @@ -794,7 +794,7 @@ static int bL_switcher_hotplug_callback(struct
>> notifier_block *nfb,
>>          return NOTIFY_DONE;
>>   }
>>
>> -static bool no_bL_switcher;
>> +static bool no_bL_switcher = true;
>
> This changes the default for everyone, which I guess is fair enough if
> there is a good reason, but I'm not sure there is.

No, I don't think there is.


-Olof