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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 3A634C7EE2E for ; Fri, 9 Jun 2023 09:59:55 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id EB66D10E675; Fri, 9 Jun 2023 09:59:53 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1255510E677 for ; Fri, 9 Jun 2023 09:59:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1686304791; 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: in-reply-to:in-reply-to:references:references; bh=Ro28qLwMycjBPd4B2CfnKUVLQYPM9zhy62Il4fiHOKA=; b=FH98xzgKJkRpFTu9S6g/KfdVu34q3ULBGJp6xPF76XLgnQCBTFsxxT6X4Qd3y5oIcdA5/F 8Cf5WAqhCrakEWQnxOoLf7zq6HqBlK8gTqyjmfvF4hz+ey3/E1vP9+dGBoS4PAtT/4EHjR 1riIk88dyhLQjZ0Hhcjrab59cJLnGCM= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-90-00Jv5T5BPUCXTmLUvOKBqA-1; Fri, 09 Jun 2023 05:59:43 -0400 X-MC-Unique: 00Jv5T5BPUCXTmLUvOKBqA-1 Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-30ae9958ff6so679778f8f.1 for ; Fri, 09 Jun 2023 02:59:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686304782; x=1688896782; h=mime-version:message-id:date:references:in-reply-to:subject:cc:to :from:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Ro28qLwMycjBPd4B2CfnKUVLQYPM9zhy62Il4fiHOKA=; b=awXSJO2AxZm3v2YXds1vzxThoJgW0NO72iPU+HoYH7hr+WOebj/egodekcyW4mK/Br +lmZX7sG+eznF2PTG5usctOIB9EbofCWqL017x2/FbtSlz5ajyKwS/a5gyHT5UqguXF1 Valoo7FACddIQ+rNIB/re+bzbGjCto9wrc3MZorR+/reiqO6N/PYD2hgIZSB4onpUfyD RuMHi3JJVI57liWRaTs0Ghalya+8zuNxBj6q7q4UF5naXg5Z2R5aUFenxs/3fS3zMz10 AbZkpyQ8m9+FJ+0ZCfhsljLRroBqTXmD6JZNVFqjzcWDAY9QDr8ArxiFmRglDLMI58m8 sEwQ== X-Gm-Message-State: AC+VfDz3bJizMWcD7Syd1NtIDLUFQgyhIsMokI8qkWwQjoykghb9wqFK H3FMgGig0d0FX6BMIzfS4S4GZCJqXb6ARwJA7B2PU2nlSMUrayYsufcvRV2UkkLMaBzqmWx8rhx y3VBimHgOKlKNGqPyCZq8jryhoVat X-Received: by 2002:a05:6000:1cc1:b0:30d:981d:a049 with SMTP id bf1-20020a0560001cc100b0030d981da049mr475565wrb.4.1686304782623; Fri, 09 Jun 2023 02:59:42 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ5mbChq3eZ0n/KPDmx58FVgNTALqSeH3ETuPMsy/BuQZAfQWRgbheMcufPP8W0/LTSPFhyPxg== X-Received: by 2002:a05:6000:1cc1:b0:30d:981d:a049 with SMTP id bf1-20020a0560001cc100b0030d981da049mr475549wrb.4.1686304782266; Fri, 09 Jun 2023 02:59:42 -0700 (PDT) Received: from localhost (205.pool92-176-231.dynamic.orange.es. [92.176.231.205]) by smtp.gmail.com with ESMTPSA id d17-20020a5d6dd1000000b003095bd71159sm4029755wrz.7.2023.06.09.02.59.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Jun 2023 02:59:41 -0700 (PDT) From: Javier Martinez Canillas To: Thomas Zimmermann , Geert Uytterhoeven Subject: Re: [PATCH 30/30] fbdev: Make support for userspace interfaces configurable In-Reply-To: <4df23439-462f-47da-890d-2dd2092eea35@suse.de> References: <20230605144812.15241-1-tzimmermann@suse.de> <20230605144812.15241-31-tzimmermann@suse.de> <873532eurg.fsf@minerva.mail-host-address-is-not-set> <77252bc9-e08e-fcee-d140-2b78ab768b42@suse.de> <4df23439-462f-47da-890d-2dd2092eea35@suse.de> Date: Fri, 09 Jun 2023 11:59:41 +0200 Message-ID: <87h6rh552q.fsf@minerva.mail-host-address-is-not-set> MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: daniel.thompson@linaro.org, lee@kernel.org, linux-sh@vger.kernel.org, jingoohan1@gmail.com, deller@gmx.de, linux-staging@lists.linux.dev, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-omap@vger.kernel.org, sam@ravnborg.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Thomas Zimmermann writes: Hello Thomas, > Hi > [...] >>> I'd also question the argument that there's even fbdev userspace out >>> there. It was never popular in it's heyday and definitely hasn't >>> improved since then. Even the 3 people who still ask for fbdev support >> >> There's X.org, DirectFB, SDL, ... > > None of these examples has a dependency on fbdev. They can freely switch > backends and have moved to DRM. Anything program utilizing these > examples has no dependency on fbdev either. > > When I say "userspace" in this context, it's the one old program that > supports nothing but fbdev. TBH I'm having problems to come up with > examples. > I personally have two real world examples that can give to you :) 1) I've a IoT device at home that has a bunch of sensors (temperatury, humidity, etc) and a SSD1306 display panel to report that. It just has small fbdev program to print that info. I could probably port to KMS but didn't feel like it. Found a fbdev program that I could modify and got the job done. 2) I built a portable retro console for my kids, that uses a ST7735R LCD panel. The software I use is https://www.retroarch.com/ which uses fbdev by default (I believe that supports a KMS mode but out of the box it works with fbdev and that's better tested by them. So even when I'm not interested and don't want to enable any of the fbdev drivers, I want to use the ssd130x and st7735r DRM drivers and the DRM fbdev emulation layer. In other words, there's real use cases for supporting fbdev programs with DRM drivers. Now, I agree with this patch-set and probably will disable the user-space fbdev interface in Fedora, but on my embedded projects I will probably keep it enabled. That's why I think that we should support the following combinations: * fbdev drivers + DRM fbdev emulation + fbdev user-space * only DRM drivers without fbdev emulation nor fbdev user-space (your series) * only DRM fbdev emulation + fbdev user-space enabled (FB_CORE) -- Best regards, Javier Martinez Canillas Core Platforms Red Hat