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([2a01:e34:ed2f:f020:a9ac:cbdb:2935:5df0]) by smtp.googlemail.com with ESMTPSA id t13sm10898775wru.65.2020.08.07.11.06.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 07 Aug 2020 11:06:50 -0700 (PDT) Subject: Re: [GIT PULL] RESEND: thermal for v5.9-rc1 To: Linus Torvalds Cc: Zhang Rui , Amit Kucheria , Andrzej Pietrasiewicz , Colin King , Shawn Guo , Lukasz Luba , Sumeet Pawnikar , Henry Yen , Thierry Reding , Linux Kernel Mailing List , Linux PM mailing list , Marian-Cristian Rotariu References: From: Daniel Lezcano Message-ID: <88678a80-4ca2-5cb0-d9c5-3e64b7f113f5@linaro.org> Date: Fri, 7 Aug 2020 20:06:49 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/08/2020 17:54, Linus Torvalds wrote: > On Fri, Aug 7, 2020 at 2:40 AM Daniel Lezcano wrote: >> >> It defaults to 'y' because the previous (but unused) implementation was >> unconditionally compiled-in and because of the thermal users needs. >> >> Is default=y wrong given this history? > > One million percent wrong. > > The fact that the old implementation was never used just shows that > it's not so important, and it shouldn't be default 'y'. Not having it > doesn't break anything. > > And the new implementation presumably isn't even compatible with the > old format also means that it shouldn't be default 'y'. Building it in > wouldn't help anyway. > > And the fact that _some_ users might want it does not mean that it > should be default 'y', because those users presumably _know_ they want > it. > > IOW, defaulting to 'y' is just wrong in every possible way. This is > not some kind of "to maintain compatibility and not break existing > users we should enable this" kind of thing. > > And it's not some kind of "everybody should have it" thing either, > since presumably nobody has the user-space support for it anyway. > > It's something that a new distro would enable _if_ they actually end > up supporting the user space. Not something the kernel should enable > "just because". > > Really: "default y" is _wrong_. Every developer thinks that _their_ > code is so magical and special that everybody should run it. > > And every developer is almost always wrong. Unless you have a "not > having this will break existing users", you don't do it. Ok, I will send a fix. Thanks for taking the time to clarify that. -- Daniel -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog