From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [Nouveau] [PATCH 3/3] drm/nouveau/kms/nv50-: Limit MST BPC to 8 Date: Mon, 18 Nov 2019 14:36:14 +0100 Message-ID: <20191118133614.GE2246533@ulmo> References: <20191115210728.3467-1-lyude@redhat.com> <20191115210728.3467-4-lyude@redhat.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="BQPnanjtCNWHyqYD" Return-path: Content-Disposition: inline In-Reply-To: <20191115210728.3467-4-lyude@redhat.com> Sender: stable-owner@vger.kernel.org To: Lyude Paul Cc: nouveau@lists.freedesktop.org, Sam Ravnborg , David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Jerry Zuo , Sean Paul , Ben Skeggs , Daniel Vetter , David Airlie , Harry Wentland , Juston Li , Laurent Pinchart List-Id: nouveau.vger.kernel.org --BQPnanjtCNWHyqYD Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Nov 15, 2019 at 04:07:20PM -0500, Lyude Paul wrote: > Noticed this while working on some unrelated CRC stuff. Currently, > userspace has very little support for BPCs higher than 8. While this > doesn't matter for most things, on MST topologies we need to be careful > about ensuring that we do our best to make any given display > configuration fit within the bandwidth restraints of the topology, since > otherwise less people's monitor configurations will work. >=20 > Allowing for BPC settings higher than 8 dramatically increases the > required bandwidth for displays in most configurations, and consequently > makes it a lot less likely that said display configurations will pass > the atomic check. >=20 > In the future we want to fix this correctly by making it so that we > adjust the bpp for each display in a topology to be as high as possible, > while making sure to lower the bpp of each display in the event that we > run out of bandwidth and need to rerun our atomic check. But for now, > follow the behavior that both i915 and amdgpu are sticking to. >=20 > Signed-off-by: Lyude Paul > Fixes: 232c9eec417a ("drm/nouveau: Use atomic VCPI helpers for MST") > Cc: Ben Skeggs > Cc: Daniel Vetter > Cc: David Airlie > Cc: Jerry Zuo > Cc: Harry Wentland > Cc: Juston Li > Cc: Sam Ravnborg > Cc: Sean Paul > Cc: # v5.1+ > --- > drivers/gpu/drm/nouveau/dispnv50/disp.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) Reviewed-by: Thierry Reding --BQPnanjtCNWHyqYD Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAl3Snk4ACgkQ3SOs138+ s6Fi2RAApHjuN6J8fn0XmvXm7CFGwT84x9lf01uGyvRtrhJ7ULOpVbTfcHXk1SL8 Ip8eaNj04DbxO73u9G+2lJkIXmVbyOKxZwCpi9A/UAAoXIspnzZZ6nCWy6124Iqm qpawUa+0q4uz8A/VdALzp60ZilNvX4pZn+mNPbK2V9lrG28vLx0iS6xc+BkMRC4Y rkDmXsdUNiCbVs8OsSK7bBCE3c+g7Z8Hu6z5h5O8yxcG2JDTVLAPindmyZ83Q0qT yqSqqi72QycmqyQ9prZylChv7/z/s7HNp6rMtGG6oCGwguZlwKdIz/Ko01hEKxbd OuX3vhGDe2bhAr/QowPbL4b5ST8ZmeyJ37lldmZAihWEK+BAQHESX/NoaWqDoctc NRIPdzWXvF2VCEy3rLNuUd24ugv+kW9zOYv0ezBoCqq2VZuxSC5Q4rQRFH94oQQ1 OHvPgNRe6P4ZX8gLiZmDdTzQsgJntf/2npXLlJv8muRDuCWqC/d8kGc9xFINqsok pPOBq5OhavcKXVO41RRju8ZqVpy0y+YYqWDynpr97SMTtp11HN3vcrZiB117xllh Fv5rY400AGDpwsaeH/eRm2a+T0Ov2DkegEPFu0IjCuKJ9xMV5RxftSw3HD/7M5hC w+hD4Ixncpohqgaml6M7U/gUIJdafT6N7D8S4LlTcKhvsDFSpVU= =Mrw/ -----END PGP SIGNATURE----- --BQPnanjtCNWHyqYD-- 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=-5.0 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 2D4A1C432C3 for ; Mon, 18 Nov 2019 13:36:21 +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 0D3F520726 for ; Mon, 18 Nov 2019 13:36:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0D3F520726 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 55EF76E516; Mon, 18 Nov 2019 13:36:20 +0000 (UTC) Received: from mail-wm1-x342.google.com (mail-wm1-x342.google.com [IPv6:2a00:1450:4864:20::342]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1AD006E516; Mon, 18 Nov 2019 13:36:19 +0000 (UTC) Received: by mail-wm1-x342.google.com with SMTP id 8so18897768wmo.0; Mon, 18 Nov 2019 05:36:19 -0800 (PST) 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:references :mime-version:content-disposition:in-reply-to:user-agent; bh=ICoZyr3X+VsofrtI0L0z7PjIiWh5QpcA81Yo9AVGZNI=; b=AALPhrZ0usCqb+quuZF2Y5lKIGyfS4NTJPs1jw2IUBlviW+PubvH1sbAeWxJh8nlqD LkTdG6jcfYhqTOOC69JNOXjRQZKcOI4P2MSWITlHyfCHQKGyTJbhMDHG0MLysBwP5EUV qwy0zp2mpTD7D5CLbBDBpTIL/SeahrFVt7Gh/mhSfsaRqO+RTVtoQG1PDls/4Q36PDyD hNJO70qDOXF+vkLhLHu1axjrjC5JjpevNwTyHFbPU1lUFI2FnbPlvDIcXGcsMXkbJZm+ XmFEsol8JWZHpRBfKoHDPhW/GuxEkj4FxQLvOeamTFqlldezWJJE7uoo3f9wm+9hPb/J 8WFA== X-Gm-Message-State: APjAAAW6Op6B9si/XQfXSbSYvTtsDtuPepvZdZvNh2BoJR8WFYwZwssm yFlSA04N+ZHYK6SfGn2i1fk= X-Google-Smtp-Source: APXvYqzx7j+WVMQ0sAzmd1Bv05Nq8OLaYPYCBonDSP517gSvheC3dqNpHHb3HJMp9ndsdJR1wtjxRg== X-Received: by 2002:a1c:7d47:: with SMTP id y68mr29143250wmc.157.1574084177630; Mon, 18 Nov 2019 05:36:17 -0800 (PST) Received: from localhost (p2E5BE2CE.dip0.t-ipconnect.de. [46.91.226.206]) by smtp.gmail.com with ESMTPSA id j12sm3459171wrb.82.2019.11.18.05.36.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Nov 2019 05:36:15 -0800 (PST) Date: Mon, 18 Nov 2019 14:36:14 +0100 From: Thierry Reding To: Lyude Paul Subject: Re: [Nouveau] [PATCH 3/3] drm/nouveau/kms/nv50-: Limit MST BPC to 8 Message-ID: <20191118133614.GE2246533@ulmo> References: <20191115210728.3467-1-lyude@redhat.com> <20191115210728.3467-4-lyude@redhat.com> MIME-Version: 1.0 In-Reply-To: <20191115210728.3467-4-lyude@redhat.com> User-Agent: Mutt/1.12.2 (2019-09-21) X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=ICoZyr3X+VsofrtI0L0z7PjIiWh5QpcA81Yo9AVGZNI=; b=TZF7c92tUCBoyjtaDI2+7q+Eie4Cbxr6nDst6dVIR7Y1p/y7hugd2KrlyaB8E6uV0Y qQcxkhTWJVXAxmuajuZeaW5Gq5r3gg4cpmvq3GBmzRkJRVmlRGFHSNODUpquLygCA52/ VyGhmcchZ9Lx+a56RQpH35Rp0BWctnPqtJrRkC10JFM5bBqmPKFYgWJyRLJzWsRwIlge OYWz+/AeHciygjmK2HDy1tx6/umHQwpaT8rVz+IEHAQdaSYVXM2Ir/q911Bu75QaetVD AiScJZVlzCGzGVxqPPAGaD4SZnAN/uCAGa6xd5udqTt3dP65u1KkI0MpKe4TzwpnQTgO QHWA== X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Laurent Pinchart , David Airlie , nouveau@lists.freedesktop.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Jerry Zuo , Sean Paul , dri-devel@lists.freedesktop.org, David Airlie , Sam Ravnborg , Juston Li , Ben Skeggs Content-Type: multipart/mixed; boundary="===============0935633985==" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Message-ID: <20191118133614.gO5IMutcJ-lv1e-EC-G2WmLyTJDVQpydFKV5KQo_uuE@z> --===============0935633985== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="BQPnanjtCNWHyqYD" Content-Disposition: inline --BQPnanjtCNWHyqYD Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Nov 15, 2019 at 04:07:20PM -0500, Lyude Paul wrote: > Noticed this while working on some unrelated CRC stuff. Currently, > userspace has very little support for BPCs higher than 8. While this > doesn't matter for most things, on MST topologies we need to be careful > about ensuring that we do our best to make any given display > configuration fit within the bandwidth restraints of the topology, since > otherwise less people's monitor configurations will work. >=20 > Allowing for BPC settings higher than 8 dramatically increases the > required bandwidth for displays in most configurations, and consequently > makes it a lot less likely that said display configurations will pass > the atomic check. >=20 > In the future we want to fix this correctly by making it so that we > adjust the bpp for each display in a topology to be as high as possible, > while making sure to lower the bpp of each display in the event that we > run out of bandwidth and need to rerun our atomic check. But for now, > follow the behavior that both i915 and amdgpu are sticking to. >=20 > Signed-off-by: Lyude Paul > Fixes: 232c9eec417a ("drm/nouveau: Use atomic VCPI helpers for MST") > Cc: Ben Skeggs > Cc: Daniel Vetter > Cc: David Airlie > Cc: Jerry Zuo > Cc: Harry Wentland > Cc: Juston Li > Cc: Sam Ravnborg > Cc: Sean Paul > Cc: # v5.1+ > --- > drivers/gpu/drm/nouveau/dispnv50/disp.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) Reviewed-by: Thierry Reding --BQPnanjtCNWHyqYD Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAl3Snk4ACgkQ3SOs138+ s6Fi2RAApHjuN6J8fn0XmvXm7CFGwT84x9lf01uGyvRtrhJ7ULOpVbTfcHXk1SL8 Ip8eaNj04DbxO73u9G+2lJkIXmVbyOKxZwCpi9A/UAAoXIspnzZZ6nCWy6124Iqm qpawUa+0q4uz8A/VdALzp60ZilNvX4pZn+mNPbK2V9lrG28vLx0iS6xc+BkMRC4Y rkDmXsdUNiCbVs8OsSK7bBCE3c+g7Z8Hu6z5h5O8yxcG2JDTVLAPindmyZ83Q0qT yqSqqi72QycmqyQ9prZylChv7/z/s7HNp6rMtGG6oCGwguZlwKdIz/Ko01hEKxbd OuX3vhGDe2bhAr/QowPbL4b5ST8ZmeyJ37lldmZAihWEK+BAQHESX/NoaWqDoctc NRIPdzWXvF2VCEy3rLNuUd24ugv+kW9zOYv0ezBoCqq2VZuxSC5Q4rQRFH94oQQ1 OHvPgNRe6P4ZX8gLiZmDdTzQsgJntf/2npXLlJv8muRDuCWqC/d8kGc9xFINqsok pPOBq5OhavcKXVO41RRju8ZqVpy0y+YYqWDynpr97SMTtp11HN3vcrZiB117xllh Fv5rY400AGDpwsaeH/eRm2a+T0Ov2DkegEPFu0IjCuKJ9xMV5RxftSw3HD/7M5hC w+hD4Ixncpohqgaml6M7U/gUIJdafT6N7D8S4LlTcKhvsDFSpVU= =Mrw/ -----END PGP SIGNATURE----- --BQPnanjtCNWHyqYD-- --===============0935633985== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVs IG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlz dHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVs --===============0935633985==--