From mboxrd@z Thu Jan 1 00:00:00 1970 From: tixy@linaro.org (Jon Medhurst (Tixy)) Date: Fri, 01 Aug 2014 16:53:19 +0100 Subject: [PATCH] ARM: multi_v7_defconfig: major refresh In-Reply-To: <53DBAAEA.2010908@arm.com> 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> <53DBAAEA.2010908@arm.com> Message-ID: <1406908399.22757.12.camel@linaro1.home> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, 2014-08-01 at 15:57 +0100, Sudeep Holla wrote: > > 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 Hmm, that is a point, there are 3 other big.LITTLE SoC's I can spot in mainline [1], and I wouldn't want to speculate how they would be affected by having the big.LITTLE switcher enabled. [1] exynos5420, exynos5260, r8a7790 -- Tixy