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=-4.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 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 871BBC433F5 for ; Tue, 7 Sep 2021 12:52:28 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 561FC6109D for ; Tue, 7 Sep 2021 12:52:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 561FC6109D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id ACE3389DFA; Tue, 7 Sep 2021 12:52:27 +0000 (UTC) Received: from mail-lf1-x131.google.com (mail-lf1-x131.google.com [IPv6:2a00:1450:4864:20::131]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5FEDF89DFA for ; Tue, 7 Sep 2021 12:52:26 +0000 (UTC) Received: by mail-lf1-x131.google.com with SMTP id n2so9810806lfk.0 for ; Tue, 07 Sep 2021 05:52:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version; bh=yd5PddgaDgBJxyg3Hd2rhZ1eCoISlbFX301E70qALbI=; b=D3hmfGbPRnrtdbqRPvRfJ0myvNdPkY/I13RZdQrQjUQvm9/zcQisnCpsSz2lWmJokO Ehm0Bej1jJ3Q0e2vS+ggrFQ/J3EZ1S/xY5+Kjw0UZu12BPJU0Dz6vpBb1T5L6Y/GdQxW jR27OU7Q65hIlMdYA/csg1u7iyJnA5aoeoxUaRIDPUyyO6RalK8FZ6MWfDdpAJOOPRdX 6IXW/JEQeymp5T0PEbSEXdxi6dvJkQM+r7Gi7eu9uYwhYvrT8ZGkDe7MvNixEhI2X5/S o16Wx9S5Eroii27yk02UGo0do8zZxfq4i51KFizDNwb1BTDz42OhuElNXMW1RndLORhD Tqhw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version; bh=yd5PddgaDgBJxyg3Hd2rhZ1eCoISlbFX301E70qALbI=; b=sUWZf70E2nb3ikQIgyxuMpERnhiogE8jiFRVNWikzCDmB//5Pp5c4cW476VYFPl6eq j9uMezSmmBjwUSfzCSpfQJi2CBq5JWpFt/hdVhsTvQ2ftGxWxDeO+jIPJ9ioifV++6Wb 5/EhQPxFFk3uFFjk/sSv1FLBO8SBSUAY/xosAeWGXRTkA72tbs5BsjhTSwhyd/ZRsX2I SfLTcdKDR7RPbXJbao04jpCA2ZgEcViL4PbQOh/J8n8zeTNwCpnKVg/xPzPGxsh14XlK NvBsM222L1aJSTTPk4T6rEGIdh8FVwPS6emSTlJkzg0T0Lx1VcB/AxtOd3WsytNfN6lE ngCA== X-Gm-Message-State: AOAM53114g/9P2jqDdtT7KihSUU0t3H2ofUYRzJ/ygGbvax0Xe7ICHge 2lko65P4xJ2Bn+9gLdfu1bU= X-Google-Smtp-Source: ABdhPJxLHDzRY/pAyK5b3L92VZJ+Xk6eNdlIqC44a8mEEgIhbC+jmb5pPK2giAE1R02roc/Vu6WSgw== X-Received: by 2002:ac2:5963:: with SMTP id h3mr12801281lfp.203.1631019144587; Tue, 07 Sep 2021 05:52:24 -0700 (PDT) Received: from eldfell ([194.136.85.206]) by smtp.gmail.com with ESMTPSA id z1sm270993lfe.137.2021.09.07.05.52.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Sep 2021 05:52:24 -0700 (PDT) Date: Tue, 7 Sep 2021 15:52:14 +0300 From: Pekka Paalanen To: Simon Ser Cc: Dennis Filder , dri-devel@lists.freedesktop.org, Hans de Goede Subject: Re: Handling DRM master transitions cooperatively Message-ID: <20210907155214.285b3561@eldfell> In-Reply-To: References: <20210907130746.7b667dac@eldfell> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: multipart/signed; boundary="Sig_//51fX8W5WNf=smQ2ki/fhaM"; protocol="application/pgp-signature"; micalg=pgp-sha256 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" --Sig_//51fX8W5WNf=smQ2ki/fhaM Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Tue, 07 Sep 2021 10:19:03 +0000 Simon Ser wrote: > FWIW, I've just hit a case where a compositor leaves a "rotation" KMS > prop set behind, then Xorg tries to startup and fails because it doesn't > reset this prop. So none of this is theoretical. >=20 > I still think a "reset all KMS props to an arbitrary default value" flag > in drmModeAtomicCommit is the best way forward. I'm not sure a user-space > protocol would help too much. Hi Simon, for the "reset KMS state" problem, sure. Thanks for confirming the problem, too. The hand-off problem does need userspace protocol though, so that the two parties can negotiate what part of KMS state can be inherited by the receiver and who will do the animation from the first to the second state in case you want to avoid abrupt changes. It would also be useful for a cross-fade as a perhaps more flexible way than the current "leak an FB, let the next KMS client scrape it via ioctls and copy it so it can be textured from". Userspace protocol is also useful for starting the next KMS client first and handing off only later once it's actually running. I'm not sure if that is already possible with the session switching stuff, but I have a feeling it might be fragile or miss pieces like the next KMS client signalling ready before actually switching to it. Thanks, pq --Sig_//51fX8W5WNf=smQ2ki/fhaM Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEJQjwWQChkWOYOIONI1/ltBGqqqcFAmE3YH4ACgkQI1/ltBGq qqcu8A//eJak1hn9p+s438qvCqO3Ig62YFUXKGlkoLswr8NjetFDJWl20vfc20pN m3/TgoWhI2TIgMBlPtVtG/4V5xcM4r7ch/zcKQLg3jJS9BDY8StXe/vvv9HiFB4r ZMxpykepPqvZm80zURziN7AXTonYYPOxsuP0dLypc0KDUCfdOsPADsPx7qWcAeSj /P380Bn7I4qKbPgN14fA61IMH2Am3s6bn8RMD5PHuKqg4F1Rjd6biSyg1EErmn94 c0lE2VSXnvY6HHzWGB4e6iYxetrWmtnRi/Fbh9F/M0w9ZaBFLMo/nLWj+ltIHau4 b/O8zP9fbEM+U36652FSjlmcNtdPC2vtOjbqsE2fke6Hbt9qgUExafLkFIPtnqCS Qa/f60P/gX5L9L9oWCUMev6JsRvlFsJ+hkssd68plv8GASkMi02CcSbMzBee0zl9 J7bepRy1PZwv2hvL9ycI6xQHUYghOjt6c4z+hmi0d/VaAilG59LCFuf0xpZ+riU+ 9Qdwte9a0Ddb6f9Pb+wfhUDrfjqzR1Kae2LuU//HdX2Budeao7IzeDUGFkQu0Yz9 LgeiJ1SQgiQIz4v4uCPj5J3T8qXAlbbT3jRzsVFA5nDMALov4neiP/Iwgu6O21Bx I6u4qNWK1Oh87Zbjgb5z+v26A/roOx6B+bbqsU5jfzEaUu2/bgU= =X3HL -----END PGP SIGNATURE----- --Sig_//51fX8W5WNf=smQ2ki/fhaM--