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=-5.5 required=3.0 tests=BAYES_00, 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 53203C433DF for ; Fri, 9 Oct 2020 13:31:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0648622277 for ; Fri, 9 Oct 2020 13:31:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388576AbgJINbM (ORCPT ); Fri, 9 Oct 2020 09:31:12 -0400 Received: from mx2.suse.de ([195.135.220.15]:41672 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732173AbgJINbL (ORCPT ); Fri, 9 Oct 2020 09:31:11 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id DD513AC3F; Fri, 9 Oct 2020 13:31:08 +0000 (UTC) Subject: Re: drmfb console switching problems/questions To: stsp , linux-fbdev@vger.kernel.org, Linux kernel References: <17980f58-c2d2-ac58-88ce-e21b5a56da39@yandex.ru> <70ce31ca-5922-584c-8631-3853c488f3c7@yandex.ru> From: Thomas Zimmermann Message-ID: <050632f0-6440-1254-2aed-931dd515ff37@suse.de> Date: Fri, 9 Oct 2020 15:31:05 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="OuhsM6hLiBvItfYpOSeTxcQ3jJj9Q09ak" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --OuhsM6hLiBvItfYpOSeTxcQ3jJj9Q09ak Content-Type: multipart/mixed; boundary="fZrlL9ftKBHdbItsmntY63Uze25lS4hVM"; protected-headers="v1" From: Thomas Zimmermann To: stsp , linux-fbdev@vger.kernel.org, Linux kernel Message-ID: <050632f0-6440-1254-2aed-931dd515ff37@suse.de> Subject: Re: drmfb console switching problems/questions References: <17980f58-c2d2-ac58-88ce-e21b5a56da39@yandex.ru> <70ce31ca-5922-584c-8631-3853c488f3c7@yandex.ru> In-Reply-To: --fZrlL9ftKBHdbItsmntY63Uze25lS4hVM Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable Hi Am 09.10.20 um 15:19 schrieb stsp: > 09.10.2020 15:58, Thomas Zimmermann =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >> Hi >> >> Am 09.10.20 um 14:16 schrieb stsp: >>> 09.10.2020 14:59, Thomas Zimmermann =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >>>> Fbdev exposes the video ram (or a shadow buffer of it) to all >>>> applications. Only one can draw at the same time. It's a limitation = of >>>> the design. To fix this, your application has to stop drawing when y= ou >>>> switch consoles. >>> OK, thanks for info. >>> Quite a sad news, if you ask me. >>> Is there any ongoing work at solving that? >> I don't think so. Both, SDL1 and fbdev, are pretty much dead these day= s. >> The solution to fbdev is DRM, which does not have these problems. >> >> You could your application under X11 to use SDL's X backend. X would d= o >> all the VC handling then. > That of course works. > I was trying w/o X. > Do you think it is possible for > me to test other techniques of > drawing under kms console? > Or fbcon and X are all that we > have? I can't say for sure. IIRC SDL2 can use DRM directly. If your application is stuck at SDL1, fbdev or X11 are the only realistic options. But the SDL dev could probably give you a better answer. Best regards Thomas --=20 Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 N=C3=BCrnberg, Germany (HRB 36809, AG N=C3=BCrnberg) Gesch=C3=A4ftsf=C3=BChrer: Felix Imend=C3=B6rffer --fZrlL9ftKBHdbItsmntY63Uze25lS4hVM-- --OuhsM6hLiBvItfYpOSeTxcQ3jJj9Q09ak Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQFIBAEBCAAyFiEEchf7rIzpz2NEoWjlaA3BHVMLeiMFAl+AZhkUHHR6aW1tZXJt YW5uQHN1c2UuZGUACgkQaA3BHVMLeiPXBwf/ZrKP64JecPLZsG/MiEQ+KIeF8qgs jJsKcghIksbGyI7DO+eyjtkQXeTSbMDeDL1NlXkE3+mGgKfX6eN4/bOI1oZsA/I2 YOHEuhgTznvWlAUfdGtkkQmSaA3iRdu/FWYQNgnz1A9HijiunGeR0/n8ZjsTeksU oMeMK9QPql9hsBtptXGNjYmAexpZPG6YbGtpmUjFJfaRMIu2wFjJKhQBLD7e3pvf 1tHgN3CBPWbDNsmqPRMIsQgagwmgTRBWwJDSuHSirY3cRV8p+jB0MzFHDbNfSuiY AZR9rbIv9LBekg8oqfdtm1dLQl7rWgoC+OYqhfwXnDsMqID0y14eNmXVcA== =C1dt -----END PGP SIGNATURE----- --OuhsM6hLiBvItfYpOSeTxcQ3jJj9Q09ak--