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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 52F9ECD8CAA for ; Tue, 9 Jun 2026 13:53:43 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9515D10E338; Tue, 9 Jun 2026 13:53:42 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=collabora.com header.i=@collabora.com header.b="ckboBTg9"; dkim-atps=neutral Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) by gabe.freedesktop.org (Postfix) with ESMTPS id E34BF10E338; Tue, 9 Jun 2026 13:53:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1781013220; bh=L98cR/ByoGK9e175bYrq4L47hW2opnbC3z5psUrV550=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ckboBTg9fcyqrbuG3aksVjfwbRoKQ/Dj5BOYDQ4Wat1Tz2/VcmfxWTHNhmmqH/lNJ GmGV0GLMIK1qPDXWpTLMCZ07zVnu0En263ZErGJG7Bpub6yUZ6kUmfCWOUD2ket3UG 6S/qoua/fT9gIMEJy95G9pSfZZaVwtzPXEPDQPw/6Wzsi9p6dBv9mI51vjsQWRxXGy JoKcLsYLphbtXFX2OpU5uT2qIz9hyHR1NCDFmV1NbBBrKk8AWSZhV8GOP+8hvH5z1v c91vc+ZQiZ27nPPU79OKWN5BEEukqGfUIVIKjuy3yzBx8A27h3ebIwzR5KL3eK8kdk tH4KOWBXhoMrQ== Received: from fluorite (unknown [100.64.0.208]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: pq) by bali.collaboradmins.com (Postfix) with ESMTPSA id 8F93F17E0433; Tue, 9 Jun 2026 15:53:39 +0200 (CEST) Date: Tue, 9 Jun 2026 16:53:06 +0300 From: Pekka Paalanen To: Michel =?UTF-8?B?RMOkbnplcg==?= Cc: Nicolas Frattaroli , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Harry Wentland , Leo Li , Rodrigo Siqueira , Alex Deucher , Christian =?UTF-8?B?S8O2bmln?= , Ville =?UTF-8?B?U3lyasOkbMOk?= , Daniel Stone , Dmitry Baryshkov , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, kernel@collabora.com, Derek Foreman , Marius Vlad Subject: Re: [PATCH v5 0/3] Add "link bpc" DRM property Message-ID: <20260609165306.67332621@fluorite> In-Reply-To: <7ad74724-9233-44ed-9b54-4c88a6a4f255@mailbox.org> References: <20260319-link-bpc-v5-0-5306cd04a708@collabora.com> <8676926.T7Z3S40VBb@workhorse> <4265353.aeNJFYEL58@workhorse> <254c20a4-cce3-4c8e-9902-514586f3e694@mailbox.org> <20260326155305.736b4e64@fluorite> <47325395-3790-4cb4-8efd-84a3d8ddb80c@mailbox.org> <20260331153805.376486e2@fluorite> <20260331172105.271c677c@fluorite> <7ad74724-9233-44ed-9b54-4c88a6a4f255@mailbox.org> X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: multipart/signed; boundary="Sig_/QAc_Qv+y6AjbFFs+expgZaA"; 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_/QAc_Qv+y6AjbFFs+expgZaA Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Wed, 1 Apr 2026 09:46:08 +0200 Michel D=C3=A4nzer wrote: > On 3/31/26 16:21, Pekka Paalanen wrote: > > On Tue, 31 Mar 2026 14:56:22 +0200 > > Michel D=C3=A4nzer wrote: =20 > >> On 3/31/26 14:38, Pekka Paalanen wrote: =20 > >>> On Tue, 31 Mar 2026 10:01:59 +0200 > >>> Michel D=C3=A4nzer wrote: =20 > >>>> On 3/26/26 14:53, Pekka Paalanen wrote: =20 > >>>>> On Tue, 24 Mar 2026 17:44:21 +0100 > >>>>> Michel D=C3=A4nzer wrote: > >>>>> =20 > >>>>>> * There's no clear use case. > >>>>>> > >>>>>> This is generally a requirement for new KMS UAPI. > >>>>>> > >>>>>> The practical usefulness of the corresponding weston MR is dubious > >>>>>> per the concern above. =20 > >>>>> > >>>>> I think the example of RGB 10 bpc to be degraded to YCbCr 10 bpc > >>>>> rather than RGB 8 bpc is an excellent use case. =20 > >>>> > >>>> This series and the corresponding Weston MR aren't enough to address > >>>> that use case though, are they? All they achieve is logging a > >>>> potentially misleading warning. > >>>> > >>>> It might make sense to combine this series and the Weston MR with > >>>> whatever else is needed for that use case. =20 > >>> > >>> What do you believe is missing? =20 > >> > >> For the stated use case, e.g. a mechanism to control RGB vs YCbCr? =20 > >=20 > > There is no need for that. Currently the driver chooses the color model > > and depth on its own. We just want to make sure it's not too low. =20 >=20 > What can be done when it's too low though? Notify the end user that their system is not performing up to their parameters. They may need to consider changing hardware. Thanks, pq > The only thing I can see is setting a higher "max bpc" value. If > that's acceptable and helps though, why was the lower value set in > the first place? (Otherwise the weston MR doesn't log the warning) >=20 >=20 > I feel like I'm still missing a piece of the picture for the > practical use. >=20 --Sig_/QAc_Qv+y6AjbFFs+expgZaA Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEJQjwWQChkWOYOIONI1/ltBGqqqcFAmooGsIACgkQI1/ltBGq qqf5EQ/+LHtQAm7P+Dsc4MhTs4n0DBDmz7WmYgtQe22U7nQ4493kVDGqX8O+YFFn DemxD/4lsXAVQPi8OEFAGtb/mdJbmJ6g+RV5tBqWtaCxU5LJ+ND8ZAhJnk4WPjOV lAgPHZf8X0iavtWm4yVWvKOsSlNI/+AK+FTSQui7qKmv96ghVdIRZz+zR6/+JmD4 +0rYGSngrpDb63vUzuxXWBpAe8IsicYVghegcHIRbvlHyJ0rc9x/P2LxMKu4Zvbl Rd8QUSW+qhzmzay0hsWkJ0bgFRNVGcmXW+KJoOg1381gqhi8I+BEAaKMAuY4kjMv 5PWBGX/4F73j2MQJzpmDnIDynumxC0jojOS5e7kAaC5tLuEkDgBgRInmgoY3TTVx +sO5jVhQeQpkpqXYBZnR2zCYP5Ql/wiQH3B89dkylAQkV1OJVUoDRuKGUjrA2sI5 phB49sfmUNGX/6XVjAA+NUhD73t2LUtE3u577zFBLoGaoYwJbAAyewmpV3cl4zP9 llDH80zIVIQy9AUWYKXq0lgpXEdNNVLRK5uqTzh8juvbcA2cAFgeLNSl9D8H18Ud Gi1QYLl8BJhWgHpUBWW1qNpgEQI6bk9Awq2gXmeoXNNeCnI3EhPOZXcIATJwuaXy cwd/a2UFifd40zNkLfNiUvPUH/GZ8p2KQZr17taGjNsnaAquy40= =NrJS -----END PGP SIGNATURE----- --Sig_/QAc_Qv+y6AjbFFs+expgZaA--