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=-7.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 209C4C433B4 for ; Thu, 8 Apr 2021 11:01:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CC3C3608FE for ; Thu, 8 Apr 2021 11:01:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229714AbhDHLBM (ORCPT ); Thu, 8 Apr 2021 07:01:12 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:56371 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230501AbhDHLBM (ORCPT ); Thu, 8 Apr 2021 07:01:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617879660; h=from:from: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=WQhqnjeZkCOh2eK1FDK8AD+p6DMcS/hFEdzGcfPMAFo=; b=Vbirf+j5/oeKrWyHHsAyReKkCVP8+9mSK+SYEN/DKRbvwPxg7sh293vcSCMuaXwb1GtqPn ho08YQA1oDMqYtSgMTU4su5nfupkCnix8QZuYQ0zG3/1vEIzPzNDNPkr2JoCqKHsaUFMYf FuhK1E8jOpmDnJdFpoRIcG3OmK1d6no= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-546-cf3ok8EPM6mmTtU9zSKjug-1; Thu, 08 Apr 2021 07:00:57 -0400 X-MC-Unique: cf3ok8EPM6mmTtU9zSKjug-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4E56F83DD21; Thu, 8 Apr 2021 11:00:54 +0000 (UTC) Received: from [10.36.114.231] (ovpn-114-231.ams2.redhat.com [10.36.114.231]) by smtp.corp.redhat.com (Postfix) with ESMTP id EF0CA5D9D0; Thu, 8 Apr 2021 11:00:48 +0000 (UTC) To: Arnd Bergmann 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 References: <20210408092011.52763-1-david@redhat.com> <20210408092011.52763-3-david@redhat.com> From: David Hildenbrand Organization: Red Hat GmbH Subject: Re: [PATCH v1 2/2] drivers/gpu/drm: don't select DMA_CMA or CMA from aspeed or etnaviv Message-ID: <7496ac87-9676-1b4e-3444-c2a662ec376b@redhat.com> Date: Thu, 8 Apr 2021 13:00:47 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org >>> In particular, it does not prevent a configuration with 'DRM_CMA=m' >> >> I assume you meant "DRM_CMA=n" ? DRM_CMA cannot be built as a module. > > Ok, at least that makes it easier. > >>> and 'DRMA_ASPEED_GFX=y', or any build failures from such >>> a configuration. >> >> I don't follow. "DRM_CMA=n" and 'DRMA_ASPEED_GFX=y' is supposed to work >> just fine (e.g., without HAVE_DMA_CONTIGUOUS) or what am I missing? > > I thought you were trying to solve the problem where DRMA_ASPEED_GFX > can optionally link against CMA but would fail to build when the CMA code > is in a loadable module. Yes. I was trying to say: it works with this patch just fine. The issue you described does not seem to apply (DRM_CMA=m). > >> Your example looks more like a NOP - no? >> Or will it have the same effect? > > The example I gave is only meaningful if both are tristate, which is > not the case here as you explain. Okay, thanks. > > It is a somewhat awkward way to say "prevent this symbol from > being =y if the dependency is =m". What would be the right thing to do in the case here then to achieve the "if DRMA_ASPEED_GFX is enabled, also enable DMA_CMA id possible"? One approach could be to have for DMA_CMA default y if DRMA_ASPEED_GFX but it feels like the wrong way to tackle this. Thanks! -- Thanks, David / dhildenb