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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 258C8C433F5 for ; Wed, 9 Feb 2022 14:42:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235138AbiBIOmT (ORCPT ); Wed, 9 Feb 2022 09:42:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235132AbiBIOmS (ORCPT ); Wed, 9 Feb 2022 09:42:18 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4CB1CC06157B for ; Wed, 9 Feb 2022 06:42:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1644417740; 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=95z5lgZr6N4bdneKS1w58+DkU3M+JrAsHlwainwdryQ=; b=bb2sPRCv2xd1Kk9NV5IWeGi3Aod15ryVM2WvAHqy4MwKMN8ECD6RXj3qCt3j24cWCnN6rd zVvACsPWBCpfrjgjcICed9WizQSsD/BMIcYWoeycnlcOCjL3JAEZDGg46eUStmipdufi2G Q0VDT71/xEb9i8GOajJ76pdgBMrqrEM= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-672-pODyunoINbq2th9WfXBlwA-1; Wed, 09 Feb 2022 09:42:19 -0500 X-MC-Unique: pODyunoINbq2th9WfXBlwA-1 Received: by mail-wr1-f69.google.com with SMTP id r2-20020adfa142000000b001e176ac1ec3so1199931wrr.3 for ; Wed, 09 Feb 2022 06:42:19 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=95z5lgZr6N4bdneKS1w58+DkU3M+JrAsHlwainwdryQ=; b=I/4YIRfDmT/hswPwxS6Ve99if50ACtdE5Q6O6ne6Hz5n//c+wfHXuJjZckIvqlMHbD L+mwk+z58v07Yg1YZqjuqmM/3m1aMYkr8dfFgseWWHAmOE9uq2UaoH8iMW9fFPFIqav7 O6G3vfWyPvu0AO05xx+5/jcuN4WeHBzLppTvrsvQhYhhxczzFq03LTJn+XcNIBVzBMKK b4ntRXhDjbBC2SxnM6b/Q7siTeRAyuCoJr7B0MyQVAOQ7J/l0AIBQRWjcICo49gx+OIn hV3+AlWSSMi/PrTsN9xSTEbQGLOWPTQyOXU6brvlZEnTLTHl3YPa+UQ9XgmkY3NUUQI1 HHSQ== X-Gm-Message-State: AOAM533uJ+pdVEW357wl373uQPz6Ljw8Dlrm47ahp4oTSNJSy0oPE7NC dRZX7CuNUczkb5rdrO5ig4dpBnmJy1bjxYhQ6AMaBRnkj2TvKESyGv0VyYeGOx0taNIZueVNJP2 gM0GBwlcdCdygzmHLo52tlF4= X-Received: by 2002:a5d:4d08:: with SMTP id z8mr2429648wrt.492.1644417738151; Wed, 09 Feb 2022 06:42:18 -0800 (PST) X-Google-Smtp-Source: ABdhPJzwDcWgtBVsSADPkjwSIWKeWh2bWga0pSclgXkPHoPRyoxL4yRrB6nhG18lTOECvpK/yDGbwA== X-Received: by 2002:a5d:4d08:: with SMTP id z8mr2429623wrt.492.1644417737881; Wed, 09 Feb 2022 06:42:17 -0800 (PST) Received: from [192.168.1.102] ([92.176.231.205]) by smtp.gmail.com with ESMTPSA id o14sm4978570wmr.3.2022.02.09.06.42.16 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 09 Feb 2022 06:42:17 -0800 (PST) Message-ID: Date: Wed, 9 Feb 2022 15:42:16 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH v2 0/4] drm/tiny: Add driver for Solomon SSD1307 OLED displays Content-Language: en-US To: Geert Uytterhoeven , Andy Shevchenko Cc: "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Linux Fbdev development list , Linux PWM List , David Airlie , Daniel Vetter , Mark Brown , Linux Kernel Mailing List , DRI Development , Liam Girdwood , Rob Herring , =?UTF-8?Q?Noralf_Tr=c3=b8nnes?= , Thierry Reding , Maxime Ripard , Thomas Zimmermann , =?UTF-8?Q?Uwe_Kleine-K=c3=b6nig?= , Lee Jones , Sam Ravnborg References: <20220204134347.1187749-1-javierm@redhat.com> From: Javier Martinez Canillas In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org Hello Geert, On 2/9/22 15:27, Geert Uytterhoeven wrote: > Hi Andy, > > On Wed, Feb 9, 2022 at 2:48 PM Andy Shevchenko > wrote: >> On Tue, Feb 08, 2022 at 04:10:49PM +0100, Javier Martinez Canillas wrote: >>> On 2/8/22 15:19, Geert Uytterhoeven wrote: >>>> On Fri, Feb 4, 2022 at 2:43 PM Javier Martinez Canillas >>>> wrote: >>>> - Kernel size increased by 349 KiB, >>>> - The "Memory:" line reports 412 KiB less memory, >>>> - On top of that, "free" shows ca. 92 KiB more memory in use after >>>> bootup. >> >> The memory consumption should really be taken seriously, because these kind of >> displays are for embedded platforms with limited amount of resources. > > Thanks for your concern! > > Looking at the options that are auto-enabled, a few stand out that > look like they're not needed on systems witch such small displays, > or on legacy systems predating DDC: Thanks for your analysis. Since drivers are replacing the {simple,efi}fb drivers and others with the simpledrm driver, the DRM subsystem is now built into the kernel and no longer a loadable module. So there has been some effort to make it more modular and smaller, as an example the following patch-set from Thomas: https://www.spinics.net/lists/dri-devel/msg329120.html But there are still a lot of room to reduce this and certainly enabling CONFIG_DRM will be noticeable for such memory constrainted systems. This is outside the scope of this patch series though, that is only about adding a new DRM driver :) Now, this is a reason why I mentioned that the old fbdev driver shouldn't be removed yet. Best regards, -- Javier Martinez Canillas Linux Engineering Red Hat