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 D4A26C433EF for ; Tue, 18 Jan 2022 08:22:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344068AbiARIWC (ORCPT ); Tue, 18 Jan 2022 03:22:02 -0500 Received: from mout.gmx.net ([212.227.15.19]:39811 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343729AbiARIV7 (ORCPT ); Tue, 18 Jan 2022 03:21:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1642494109; bh=iEnrxoLs+M+Xhm5bqXFfPM9bJaACNANweZulGOVxe2s=; h=X-UI-Sender-Class:Date:To:Cc:References:From:Subject:In-Reply-To; b=it/n+Bu20A+rDNDARaFFa+TClsrGy3v7xNggTzObRv2hWXBJDaiS5QWdmqVX5CnEA riJkhb7xVYVNa+VoRz2xhGni4zmOrFtS5R5N5C3yjt5YOONt86IfERImdTEruH1aR0 R8PbyBV1//daa3DnuVQYelqwCjUS6UdF1TbDj69k= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [192.168.20.60] ([92.116.155.155]) by mail.gmx.net (mrgmx005 [212.227.17.190]) with ESMTPSA (Nemesis) id 1MtfJd-1mJpgI0h8p-00v9Bg; Tue, 18 Jan 2022 09:21:49 +0100 Message-ID: Date: Tue, 18 Jan 2022 09:20:43 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.3.0 Content-Language: en-US To: Gerd Hoffmann Cc: Daniel Vetter , Linux Fbdev development list , Sven Schnelle , Linux Kernel Mailing List , DRI Development , Javier Martinez Canillas , Geert Uytterhoeven , Thomas Zimmermann , Linus Torvalds References: <20220117125716.yjwxsze35j2ndn2i@sirius.home.kraxel.org> <70530b62-7b3f-db88-7f1a-f89b824e5825@suse.de> <57d276d3-aa12-fa40-6f90-dc19ef393679@gmx.de> <20220118062947.6kfuam6ah63z5mmn@sirius.home.kraxel.org> From: Helge Deller Subject: Re: [PATCH] MAINTAINERS: Add Helge as fbdev maintainer In-Reply-To: <20220118062947.6kfuam6ah63z5mmn@sirius.home.kraxel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:prWw9Xzsb49CRbqWjcdFLIUei76xAcWz2JUkyRqfu6+rvcGmd7o MpFTdhlErIj5qC+iOCYB7gLwlqvPwELibl4pUuPJK9rLPx2JJpeg+uJpUmbQUwDNbXZ5dNc svt0Q1GTrGyNf7GrJCs5/9KQYDG41yqUF0RUd4crRs8DSoJ2gMW5AsMSFGR0Rrs27+kfAWN rB88KhNOGtfKEk7RAh8QA== X-UI-Out-Filterresults: notjunk:1;V03:K0:CprwXkI8ZOI=:TgwiIbvFKPZjAL3KebNfYh 3KExnKEjR0oUcn7JWXiFZ+6gda2EkX20oih1TkXpdKQWCgyK/gFNWNVJrVUi97x7wlHCPKECn vz2nO6Ee8htWmtmAbyJOJnZ9o9gy3YkekEbOuiFayEAjerZy+QT2pWhqiHo0Im8n73H9Q+rTN xT6ZvDFJQi2cCpeUEkiro4ekhWlEtMGueN7ILWjFD0Ydgu0WfjIcI13nXzGUNqAN1wObOPXEe kcfLBMrpiCBBB1i1ISNdgYyLNP74MwhikRDkfLev16OM6FcCp0qX4StpSKEEzTeQ98qDN0skn u2gdNo2MyxWayMFrVzvvPysykU90bRPZjWcmqRCJCbiIaZKh98kU84CfdG2iP6LIpPnWzxHR5 KDunMMUm32ZAw+szYFtDnwAatJFRYA8CRuGJ76fsFvK+aYMrYrD0Q15MxyqJ5kb+2JkaMu070 LtdfjVZwr/CGCGYFea2xDHHiQPL4LTt5Nr6cAMz0XCV69rxRkhplrggGGpjWo1TA/xUhSix+W aj632CRP/F4NL1v19yYP3gO2FZ7+4OWL6Ds6pEqhyKXVMfBSc+QP4x43Xv3vFCSbKwTdkzCHA nRQ4pJ/Hp9c2BgXPtK7hJAdzznCweiktAeUjZvmbt6kIbKsTg7FypagkCwI6Ny6CsxeVIlyXw 1OUCzQIns+TKzvJqMqQ+P/NaHgn3uz8wwAz83kr9xFoPL8eLB+xIbBDOUKkaIKwAyxPfzkFtV XFIHGtOOQpk4R6V3nZK3nrP9COyyN2tWnfCDGvSF32Fu2biWIz1+cnOzyVtXE5/yeCpIP8i5v 4yuyeAxu7Thkkztc6tPHpIKkSzqULxzUxtqViFsN7+x9OLez7PgRLZeYR0+MAWGWz/iVv+Niw DXN+DoAGOay3BQolOA6THzysTCrFNZbkoNQO6oZd8cIvw0v7S9eGT13DXfXRvJQUzRn4LRW6Y DOVVjjSXrrqfbQAjdlF7KZr1wyiwB/SdxcsbCk41Qc9T6FHYZLq/ZqRM+LiKcsUVYbMKe3ZD2 12to/9cUh3FqkyrpuLn3IIXdMDR+ox9JxP/A8zWPxmCbjYdi7ZfX0D2zhb0EwPKpUXPnbMz1X ABrSsl1epg843o= Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/18/22 07:29, Gerd Hoffmann wrote: >> Please correct me if I'm wrong, but text-console emulation/scrolling on= DRM is >> currently unaccelerated and bound to Truecolour modes only, > > Yes. Adding support for formats beside argb8888 to the drm fbcon > emulation shouldn't be that much of a problem though. Really? Assuming a graphic card which runs with only 256 colors framebuffe= r is easily supported by DRM, and you can use fbcon without using lots of me= mcpy()? > Acceleration is harder. The scroll acceleration had issues nobody > addressed for years, and on modern hardware it is simply not used, which > is probably the reason nobody stepped up fixing things and it ended up > being dropped. The DRM layer doesn't use scroll acceleration. More than 30 other existing fbdev drivers use it. > Bringing it back is much more work than just reverting the commits remov= ing it. Reverting those commits have no effect on DRM's usage of fbcon. But reverting those commits bring back scroll acceleration for all others. I'm trying to find out which patches did apparently fixed such issues for the REDRAW case. If you have a pointer it would be helpful. > Also note that using a shadow framebuffer allows to decouple fbcon > updates and scanout framebuffer updates. Can be used to speed up > things without depending on the 2d blitter. Not on older hardware. Helge