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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55432C433E4 for ; Mon, 27 Jul 2020 17:12:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2A59A206E7 for ; Mon, 27 Jul 2020 17:12:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=crapouillou.net header.i=@crapouillou.net header.b="RUtGBy/i" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729267AbgG0RMp (ORCPT ); Mon, 27 Jul 2020 13:12:45 -0400 Received: from crapouillou.net ([89.234.176.41]:57330 "EHLO crapouillou.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728939AbgG0RMo (ORCPT ); Mon, 27 Jul 2020 13:12:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=crapouillou.net; s=mail; t=1595869961; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QQPLs8G7xnlp4G++Lxr0CaXPWeOA/xM0miRvxkULoFU=; b=RUtGBy/i4V/XNluTUdmDFr74yRTLWR7L1GRbbP9w7yddGXxuLrCUkfhlvzs4CPyU6AYG5P lSEix0m2n1AsiO3Ft1WNq/ulI22WuJxsx+PDi0yGmbG6tWTwJ7HQApZL8etJXeDW8n3Z51 HR3qTj0qqZoxYAjpBwCmrB8+rbnG1h4= Date: Mon, 27 Jul 2020 19:12:32 +0200 From: Paul Cercueil Subject: Re: [PATCH v3 2/2] mtd: rawnand: ingenic: Limit MTD_NAND_JZ4780 to architecture only To: Krzysztof Kozlowski Cc: Arnd Bergmann , Harvey Hunt , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , linux-kernel@vger.kernel.org, linux-mtd Message-Id: In-Reply-To: <20200727170302.GA3507@kozik-lap> References: <20200724155436.GA7460@kozik-lap> <20200726160616.GA2662@kozik-lap> <20200726161545.GA6058@kozik-lap> <20200727170302.GA3507@kozik-lap> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le lun. 27 juil. 2020 =E0 19:03, Krzysztof Kozlowski a=20 =E9crit : > On Mon, Jul 27, 2020 at 09:55:54AM +0200, Arnd Bergmann wrote: >> On Sun, Jul 26, 2020 at 6:20 PM Paul Cercueil=20 >> wrote: >> > Le dim. 26 juil. 2020 =E0 18:15, Krzysztof Kozlowski=20 >> a =E9crit : >> > > On Sun, Jul 26, 2020 at 06:12:27PM +0200, Paul Cercueil wrote: >> > >> Le dim. 26 juil. 2020 =E0 18:06, Krzysztof Kozlowski=20 >> a =E9crit >> > >> > > OK, that's true. Anyway, I don't have strong opinion on any of=20 >> this. I >> > > just followed Arnd's hint. >> > > >> > > For the memory driver (and MTD NAND as well) which one you=20 >> prefer: >> > > 1.=20 >> https://lore.kernel.org/lkml/20200724074038.5597-6-krzk@kernel.org/ >> > > 2. depends on MACH_INGENIC || MIPS_GENERIC || COMPILE_TEST >> > > >> > > ? >> > >> > I'd say a slightly modified #1. The driver shouldn't be "default=20 >> y" in >> > the first place, so the patch could be to disable it by default. >>=20 >> If it defaults to 'n' even for MACH_INGENIC, you may have to enable >> it in the four defconfig files for these machines to avoid=20 >> surprises. >=20 > Exactly. Nothing else selects JZ4780_NEMC, so either we keep default y > ("if MACH_INGENIC || MIPS_GENERIC"), or you select it directly from > MACH_INGENIC/MIPS_GENERIC. >=20 > A related question is how essential are these drivers? At least for=20 > ARM > platforms, all essential SoC blocks/IPs are selected by default, if > support for chosen SoC is enabled. Only non-essential stuff is left, > e.g. DRM, cpufreq, devfreq, ADC, crypto, video, USB, eMMC (although=20 > one > could argue that it is essential), IOMMU. They are only used for NAND access, which is not really essential (some boards only use MMC storage), that's why I said they shouldn't have been enabled by default in the first place. -Paul >=20 >> > And when the Ingenic code is merged into the MIPS generic=20 >> framework, I'll >> > send a set of patches to change all driver dependencies on MIPS to >> > MIPS_GENERIC. >>=20 >> The way we do it on Arm, the machine Kconfig identifiers stay around >> even for multiplatform targets (which now make up basically actively >> maintained machines). >>=20 >> I don't think it makes any sense for a driver to depend on=20 >> MIPS_GENERIC: >> either it is a generic driver that should always be visible or it=20 >> is specific >> to a set of SoCs and should depend on some corresponding vendor >> specific identifiers. >=20 > If support for Ingenic is provided also by MIPS_GENERIC (without > selecting MACH_INGENIC), then it makes sense. This would be just a > different way than ARM of building multi-platform kernel. >=20 > Best regards, > Krzysztof