From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 82BAAC636CD for ; Fri, 10 Feb 2023 08:52:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=YZAhfBQYquLF1qnZYO3CTH5oSKC+08iiTknQihvWDiA=; b=Lepv/DadiISCaz//avSl+XVxAg 0Ee3xilGqL+gSgTIVXKGGmvZHCD2kX00wEJDRkze3z+mGM3/AmnNZrx/R7UfU65Xl4RnCBHD9vjEV 0pYXy64f/l1xfgnCSXzkA0DT1HWHkQgakkPJ4RcUvtDNaJDDf+c0c5LjQiN2I7G8hLNU3OaoW3Yfj kvghJXFIDphIlN4zS1zlbp8NqqgI4HZkhgTp93Wm1AZdrQe325OYQhKz9UcEQZNM+KHLVGuakUVNl 33D9M33a//AHC5rSfoNd0gzqkhTelMQNv/3i3eqgdYVvID71Qo2j2pch283xX9xExlrHhXgQW8uRI cLsLSxkg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pQP8X-004qZv-Hz; Fri, 10 Feb 2023 08:52:05 +0000 Received: from mail-wm1-x330.google.com ([2a00:1450:4864:20::330]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pQP8T-004qYP-SK for linux-mediatek@lists.infradead.org; Fri, 10 Feb 2023 08:52:03 +0000 Received: by mail-wm1-x330.google.com with SMTP id z13so3279890wmp.2 for ; Fri, 10 Feb 2023 00:52:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=YZAhfBQYquLF1qnZYO3CTH5oSKC+08iiTknQihvWDiA=; b=fwGE+8ZXY4Cqp7eooYZ0dYLd+1x3muucfpFXGjo9lEDwCb9aW536kfIl5wvOL9ukDK ZPOW4f5iyqFYvMSxowTCoJKZebalcQT5tqGc4gg+WWV/O1Xlqhry3TsT/jfvogtix2ou VsVh/c8fKkXC3yf2bGsdgSUScN0i1uIdjU2hgzAHyeRqmW0IAhHho218gODY5fUtUORK /pSadvC4Q6tD01pE63iGs0cxFKNdc3CgZKIyKjPSTraWX//sx/g1A2eqBxAZa/1vCVc8 +KspIoqrJ4Weklwd0UDwAUv+/YQGT5bROiuQb1WBScSPXC6T2RBAqKqoJ2C2wihh9Bpy BLkg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=YZAhfBQYquLF1qnZYO3CTH5oSKC+08iiTknQihvWDiA=; b=n0WRFhUze3paYdq+McYbekRIGAyxmcblSBqcjEj8e/X7vTLt6xVsQjpHlUJrHejstI uHL/C9kVUnWUtpmgSFSJehhjywkIIYG91EnjRVvK0Y7jG3N6i3OYyeHd9ERHhMEIr8OS JMOezqN8OagitevQ6u25hd61153OIN2EJ1YvMgc+ea6xx349e441FHmmuqNUNhwMqN9N Zzga+O9sOvZIELOi9lgt0rYN/2ChSHFuZOkLj9trzxuqai3mW5TQzHhSX5yPrSfHnS3p syeasjBc39+e6uvha6cHjqRJo8YgjzAsi6e+s4dkLUj+qCy+VUch1YkpQENM8wpenooK vKKg== X-Gm-Message-State: AO0yUKW7kYNR9EH9VoBiI11XJ8GIoej9KvV5dJ3zlY+DgVoX9CTPuuSN BxtXvMhPGV1/l8r8xlsqPFkUXQ== X-Google-Smtp-Source: AK7set/OKo4yEv07P848igeq6Jgq0peHDJLiD5bvtcLGw5Ybo81esX+fCq4M7Yn6i8m3EQT/mZjzEA== X-Received: by 2002:a05:600c:4386:b0:3df:94c3:4725 with SMTP id e6-20020a05600c438600b003df94c34725mr12272914wmn.38.1676019120422; Fri, 10 Feb 2023 00:52:00 -0800 (PST) Received: from linaro.org (wifi-eduroam-trans.univ-tlse3.fr. [195.220.58.237]) by smtp.gmail.com with ESMTPSA id n13-20020a05600c3b8d00b003dc434900e1sm4771255wms.34.2023.02.10.00.51.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Feb 2023 00:52:00 -0800 (PST) Date: Fri, 10 Feb 2023 09:51:57 +0100 From: Daniel Lezcano To: John Stultz Cc: walter.chang@mediatek.com, Thomas Gleixner , Matthias Brugger , AngeloGioacchino Del Regno , "Maciej W . Rozycki" , wsd_upstream@mediatek.com, stanley.chu@mediatek.com, Chun-hung.Wu@mediatek.com, Freddy.Hsin@mediatek.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: Re: [PATCH 0/3] Support timer drivers as loadable modules Message-ID: <20230210085157.GA175687@linaro.org> References: <20230208094813.20874-1-walter.chang@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230210_005201_959664_C2AEA1D2 X-CRM114-Status: GOOD ( 22.32 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On Thu, Feb 09, 2023 at 11:50:49AM -0800, John Stultz wrote: > On Thu, Feb 9, 2023 at 7:36 AM Daniel Lezcano wrote: > > > > On 08/02/2023 10:48, walter.chang@mediatek.com wrote: > > > From: Walter Chang > > > > > > This patch exports functions in kernel so that timer drivers, > > > such as timer-mediatek.c can become loadable modules in GKI. > > > > What for ? > > In general, it's the same reason why modules exist: We want to be able > to support a wide array of devices with a single kernel, but we don't > want all devices to pay the memory cost of code that will never be > used there. So being able to support loading device-specific bits like > clocksources (along with other device specific logic) helps. Agree, that is why modules are for. > Obviously it still has to make sense, and others have raised concerns > of stability issues if the hardware support is needed before we can > get to module loading, but I think if this allows drivers (such as > timer-mediatek) to be loadable safely, I see it as beneficial. >From a technical point of view, it is arguable. But my main concern is the real reason of changing this to the module format. I see that as a way to overcome the effort to upstream the drivers. And the GKI is an alibi to justify the module conversion. Given the timers is a base brick of the core subsystems, without proper support of the timer (eg. bug fixes), the platform support will be wobbly. -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog