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=-10.8 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=ham 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 75E7AC4363A for ; Mon, 26 Oct 2020 13:43:01 +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 2833424640 for ; Mon, 26 Oct 2020 13:42:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fnQBuMDl" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2833424640 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 8A4676E141; Mon, 26 Oct 2020 13:42:58 +0000 (UTC) Received: from mail-lf1-x142.google.com (mail-lf1-x142.google.com [IPv6:2a00:1450:4864:20::142]) by gabe.freedesktop.org (Postfix) with ESMTPS id D37726E141 for ; Mon, 26 Oct 2020 13:42:57 +0000 (UTC) Received: by mail-lf1-x142.google.com with SMTP id z2so12148133lfr.1 for ; Mon, 26 Oct 2020 06:42:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version; bh=qgYsqaivfetMk7mvJHK3FQ2a1CMb2JLPvPHJjDRvsYs=; b=fnQBuMDlszJP7R8ECIaEOj4mVCC8tewpe2/nodqKi0M5wsp4AV0bW2e9EanoybTDGx olTPG7x9ErD88p11BkUKLr1NJpg/xTY/RwMZNpzMNLvyxWIl1PpLW+j5mJ9qeo+6ibnF n3K8RxqqlOalqhyLTwwaBJnPK84PJTZdFExbLA6ztrzdJ5T7ptkFQ7CD7NMYPKqC7/Aj iEx/HxszKiIajjyDbsVWr15V9qO6f10ejgSmMGEjODKjNLOHlvzCq7Q3Nm09HF+ad70y AMzZT1vToMPHISO9zBaWdiJJStTiTThpBjQhut76RzP4C7CSf8BFLeDg5Xhef9uVCJtd HmNQ== 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=qgYsqaivfetMk7mvJHK3FQ2a1CMb2JLPvPHJjDRvsYs=; b=NuzIIrmwuJaMkx5pO1VxCxnOJMAWIS5tzshil+G/BAXLcdFe2HqvPb8dUUrlVvgSuF oXz26vZZPSkSvpAXeCMPxpzntI3z3n0caoqPLB6GpzDh6gIxsgNb6IAYhyjU67yZqwjd JQZ6OB5SfBgB5ZbORmqtnE616zm+6kMbVnGWkXnKXTBR+H6y9VqU6k7ME5S6tW9NwK8r JZy3OG8WyiRANeR8tTtfg3q69cHz0APjVQUUp6z77s4lQwW/c2n30Wy3kupUAjrH5WSK LVdBK3UQjN1hLdIq3Lxrx41EB8Q62Rjk4IqxgBUudMTrtcrG65qzJJJA9NQ69vCG/q9+ 3FKw== X-Gm-Message-State: AOAM530QBxCa6apzSqoF7r1WOvvhSfz1TvGBo/mOgzEDaOLKEhUXrS/Z euTfnCxpX4j1YSurundiXgw= X-Google-Smtp-Source: ABdhPJwOS6KJTs7WMgzoN/tniVJKKVLEY1kOXe9iJLFGTON0fVECMMdW32YH+P+HnyIpW76dnoitKA== X-Received: by 2002:a19:e015:: with SMTP id x21mr5717851lfg.586.1603719776091; Mon, 26 Oct 2020 06:42:56 -0700 (PDT) Received: from eldfell ([194.136.85.206]) by smtp.gmail.com with ESMTPSA id r3sm1039779lfm.287.2020.10.26.06.42.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Oct 2020 06:42:55 -0700 (PDT) Date: Mon, 26 Oct 2020 15:42:52 +0200 From: Pekka Paalanen To: Simon Ser Subject: Re: [PATCH v2] drm: document that user-space should avoid parsing EDIDs Message-ID: <20201026154252.62817c86@eldfell> In-Reply-To: References: X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 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 Vetter , Thomas Zimmermann , dri-devel@lists.freedesktop.org, Daniel Vetter Content-Type: multipart/mixed; boundary="===============1578656313==" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" --===============1578656313== Content-Type: multipart/signed; micalg=pgp-sha256; boundary="Sig_/BXzoeGih0r/RiwRrxpw66VI"; protocol="application/pgp-signature" --Sig_/BXzoeGih0r/RiwRrxpw66VI Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Thu, 22 Oct 2020 10:34:44 +0000 Simon Ser wrote: > User-space should avoid parsing EDIDs for metadata already exposed via > other KMS interfaces and properties. For instance, user-space should not > try to extract a list of modes from the EDID: the kernel might mutate > the mode list (because of link capabilities or quirks for instance). >=20 > Other metadata not exposed by KMS can be parsed by user-space. This > includes for instance monitor identification (make/model/serial) and > supported color-spaces. >=20 > v2: add short explanation why user-space shouldn't do this (Brian) >=20 > Signed-off-by: Simon Ser > Suggested-by: Daniel Vetter > Reviewed-by: Daniel Vetter > Acked-by: Thomas Zimmermann > Cc: Pekka Paalanen > Cc: Ville Syrj=C3=A4l=C3=A4 > Cc: Brian Starkey > --- > drivers/gpu/drm/drm_connector.c | 5 +++++ > 1 file changed, 5 insertions(+) >=20 > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connec= tor.c > index 717c4e7271b0..1913d8b4e16a 100644 > --- a/drivers/gpu/drm/drm_connector.c > +++ b/drivers/gpu/drm/drm_connector.c > @@ -960,6 +960,11 @@ static const struct drm_prop_enum_list dp_colorspace= s[] =3D { > * drm_connector_update_edid_property(), usually after having parsed > * the EDID using drm_add_edid_modes(). Userspace cannot change this > * property. > + * > + * User-space should not parse the EDID to obtain information exposed v= ia > + * other KMS properties (because the kernel might apply limits, quirks = or > + * fixups to the EDID). For instance, user-space should not try to parse > + * mode lists from the EDID. > * DPMS: > * Legacy property for setting the power state of the connector. For at= omic > * drivers this is only provided for backwards compatibility with exist= ing Reviewed-by: Pekka Paalanen Thanks, pq --Sig_/BXzoeGih0r/RiwRrxpw66VI Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEJQjwWQChkWOYOIONI1/ltBGqqqcFAl+W0lwACgkQI1/ltBGq qqfNwhAAkxEL9xWydAkthiEpO0xnsPQgtOWimZ69H67nQXEW/INS0dkPYbXLXEoc 2jL0RQaxtWI4PiibJx0cB34oBO2LUUX4R02/XJqc22bknd6AlO1lLpPko6vsYqEY u5KOOHqbROQAo1qnyVxu0SD4CDMy8ZkWxHTaM2ICU+bTkdZuuEsuS1Ppn0shQ6KG xdEvK58JyJYkvylyHiyHJ2ts4U+8Ptk92w51TKM6zQIrdbtoBUTETqcj89aJR/QR /6tnK/WakUtaby5kgRmTJ6dN96SmpRYfSCJMdGtW705T+7Ukmt65AOcEBXzWUhBM HrtB4amCAydyYy0I7OMFs/zL1F5hrl0yj1F+ceaZ0g7nbSICYHt59titAZbJUdmH 2k2Ft1SHWoEFzuhGU2/5NJRNXe4hwkaOd4dkCyg8akTdwWuJQWUK0v5cSuS34Fzn OEebrvRjRFCnPSdD4379dr+iB4faNnlek3ysmeGBq7OxPqrY2AsoqZLhHVijTtuc WxPFm2yEJ2W9S8sRWdKR8IlOTtygf6+lS1m30TEDO4SIT2lkIHt5KLyPPydDEDTo bokaV7B49pdvmDgo/G4nNN8M3FKuEowSvDAYByUuQ67P+H7bWlL4oRIbeegMPXNo BFnEj3/vrHQWIerRN4UAvQ5bDuqJERt615tPOJaqNq4GAXEaJGY= =Bb7I -----END PGP SIGNATURE----- --Sig_/BXzoeGih0r/RiwRrxpw66VI-- --===============1578656313== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel --===============1578656313==--