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, 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 7784AC433ED for ; Thu, 8 Apr 2021 10:21:12 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CCEAA61164 for ; Thu, 8 Apr 2021 10:21:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CCEAA61164 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arndb.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 532F86B0078; Thu, 8 Apr 2021 06:21:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4E3356B007E; Thu, 8 Apr 2021 06:21:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 35D636B0080; Thu, 8 Apr 2021 06:21:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0026.hostedemail.com [216.40.44.26]) by kanga.kvack.org (Postfix) with ESMTP id 194BE6B0078 for ; Thu, 8 Apr 2021 06:21:11 -0400 (EDT) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id C5EF11830EF5C for ; Thu, 8 Apr 2021 10:21:10 +0000 (UTC) X-FDA: 78008807100.17.731FEAC Received: from mout.kundenserver.de (mout.kundenserver.de [212.227.126.187]) by imf16.hostedemail.com (Postfix) with ESMTP id 8956B80192E5 for ; Thu, 8 Apr 2021 10:21:09 +0000 (UTC) Received: from mail-oi1-f173.google.com ([209.85.167.173]) by mrelayeu.kundenserver.de (mreue009 [213.165.67.97]) with ESMTPSA (Nemesis) id 1MUGmJ-1l3k073CDb-00RIPO for ; Thu, 08 Apr 2021 12:21:08 +0200 Received: by mail-oi1-f173.google.com with SMTP id n140so1610390oig.9 for ; Thu, 08 Apr 2021 03:21:08 -0700 (PDT) X-Gm-Message-State: AOAM533KcKbGZpI300BEaAoFCddun2oAhhsVGThvNJjuBGnpzhsrvWrR vJjFAZ3CQ1ZT3zZOJXiH0D+D5P4mNX8KCxoj8uA= X-Google-Smtp-Source: ABdhPJy3jeKTxPcNwfngsbvoonksh80soCCHxiz4gKJ4G+0Fm3IstMzm5ZSVa0dFJZ+2JUBZ8yF1Sx9mjNQUOlISLnU= X-Received: by 2002:a05:6808:3d9:: with SMTP id o25mr5654228oie.4.1617877267082; Thu, 08 Apr 2021 03:21:07 -0700 (PDT) MIME-Version: 1.0 References: <20210408092011.52763-1-david@redhat.com> <20210408092011.52763-3-david@redhat.com> In-Reply-To: <20210408092011.52763-3-david@redhat.com> From: Arnd Bergmann Date: Thu, 8 Apr 2021 12:20:50 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v1 2/2] drivers/gpu/drm: don't select DMA_CMA or CMA from aspeed or etnaviv To: David Hildenbrand Cc: Linux Kernel Mailing List , Linux-MM , Joel Stanley , David Airlie , Daniel Vetter , Andrew Jeffery , Lucas Stach , Russell King , Christian Gmeiner , Mike Rapoport , Bartlomiej Zolnierkiewicz , Linus Walleij , Michal Simek , Masahiro Yamada , Randy Dunlap , Peter Collingbourne , linux-aspeed , dri-devel , Linux ARM , The etnaviv authors , Linux Fbdev development list Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:5PlV7N+JTLQY/ZLBMX3+mluQweRlStj+5ujpVZ3FzLvC7m+4fUe gIpPuvORGZj+PbLpRyB/cj4EZy+LPpd6LkYRvz4YeNDvxqdL1EvWDt/BTnJvjHlqAF/MwFQ PQT2M3xu3mfeQm037rRbgkMYX96SQOmycwcw1mNMtbvIUpuRo3lRb7rL/5GxuFwj9e4y13t yviazh5xGDylHp0cZ4Zww== X-UI-Out-Filterresults: notjunk:1;V03:K0:y2Uupavn+8I=:M7PD5fBxD+suF422N2BgPY 8QTGAzkpzG+9fLb7Ph09QfwK8Tc/emxMPguuVquF8O6SRVRqyhSKGFOosn7GtRzgOtho67zmk vOjxnINWuUa/Qjrl/DpymUdLpDizMJdShuEssPA6bZ3b5qdB2q/rljmfuUU0rWctCCFv4zPjQ JmgVlw871J2DLzJFvBiskN3IZSkXQuS/k1QpAwfh7oXJ4RXZwhCHEt2IvGFttHDnow11v8oMv mqhFGeOV4TV8YRdFMLWACBCn0RwHdm6eGtXd5OoC9DEckR+twE53L2fyJdJE/q88cokA3Wiqd /mKHBgaNngGSVeif0L+1PWu5B4eBo5Z7T6kYe/OZdmgKUdwzhYgVAjA7PdFDewJf8+4IZL9yS Igafm7rFY0v8dij1qx1kgMntDi5cByfgNJYZxbVlQz9dVfWT6Lj+QolGuYPWHxutn2CS7ns4r 857SZ4hJbPbMpeGojeFElFHJFmjmTDAoRitcq7XI0/segGoCp7ERDHugexAnbfzSPytOWgMVH bYMMXig4BWfL/92Q0WQC1CBLI4d/cAs9eB5MwzSdOzE2y5gXcRuI5sDg7P4BqicZTzTHn8NzQ B5EQOM1vb8NLTgdRRox6RHKItWkcWrfzND X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 8956B80192E5 X-Stat-Signature: 5x7qjo3rsicj1fi7tn8bmxqoawnzz8e8 Received-SPF: none (arndb.de>: No applicable sender policy available) receiver=imf16; identity=mailfrom; envelope-from=""; helo=mout.kundenserver.de; client-ip=212.227.126.187 X-HE-DKIM-Result: none/none X-HE-Tag: 1617877269-514618 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Apr 8, 2021 at 11:22 AM David Hildenbrand wrote: > > Random drivers should not override a user configuration of core knobs > (e.g., CONFIG_DMA_CMA=n). Use "imply" instead, to still respect > dependencies and manual overrides. > > "This is similar to "select" as it enforces a lower limit on another > symbol except that the "implied" symbol's value may still be set to n > from a direct dependency or with a visible prompt." > > Implying DRM_CMA should be sufficient, as that depends on CMA. > > Note: If this is a real dependency, we should use "depends on DMA_CMA" > instead - but I assume the driver can work without CMA just fine -- > esp. when we wouldn't have HAVE_DMA_CONTIGUOUS right now. 'imply' is almost never the right solution, and it tends to cause more problems than it solves. In particular, it does not prevent a configuration with 'DRM_CMA=m' and 'DRMA_ASPEED_GFX=y', or any build failures from such a configuration. If you want this kind of soft dependency, you need 'depends on DRM_CMA || !DRM_CMA'. Arnd