From mboxrd@z Thu Jan 1 00:00:00 1970 From: sudeep.holla@arm.com (Sudeep Holla) Date: Fri, 01 Aug 2014 15:57:46 +0100 Subject: [PATCH] ARM: multi_v7_defconfig: major refresh In-Reply-To: <1406892491.2794.58.camel@linaro1.home> References: <1406052070-6207-1-git-send-email-olof@lixom.net> <53DB6B4F.9080605@arm.com> <1406890899.2794.40.camel@linaro1.home> <53DB763A.10306@arm.com> <1406892491.2794.58.camel@linaro1.home> Message-ID: <53DBAAEA.2010908@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 01/08/14 12:28, Jon Medhurst (Tixy) wrote: > On Fri, 2014-08-01 at 12:12 +0100, Sudeep Holla wrote: >> >> On 01/08/14 12:03, Olof Johansson wrote: >>> On Fri, Aug 1, 2014 at 4:01 AM, Jon Medhurst (Tixy) wrote: >>>> On Fri, 2014-08-01 at 11:26 +0100, Sudeep Holla wrote: [...] >>>> >>>>> 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. >>> >> >> It's just that people using TC2 will suddenly see 3 of the 5 CPUs missing. > > Yes, if they we're previously using multi_v7_defconfig (do people > working specifically with TC2's use that?) > I don't, but assumed many might use it. > Conversely, with the change in default proposed above, anyone with their > own configs enabling the switcher will suddenly see the number of CPUs > go from 2 to 5. We also have the situation where we have a config > option, which when enabled, doesn't actually do anything unless the user > also changes boot arguments or takes measures to enable it after boot. > Which seems the wrong way for things to work to me. > OK, makes sense. Just curious how many big.LITTLE platforms have CPUFreq support and integrated with bL switcher. Otherwise we end up switching clusters/cpus using dummy i/f anyways(and probably that's the reason why that config is enabled which I missed to understand initially as I was thinking it's more for development and testing only). If is that's acceptable for those platforms, then it should be fine I believe ? Regards, Sudeep