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 EC7EAC43460 for ; Tue, 11 May 2021 08:08:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD0426147D for ; Tue, 11 May 2021 08:08:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230442AbhEKIJQ (ORCPT ); Tue, 11 May 2021 04:09:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46940 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230126AbhEKIJP (ORCPT ); Tue, 11 May 2021 04:09:15 -0400 Received: from mail-lj1-x241.google.com (mail-lj1-x241.google.com [IPv6:2a00:1450:4864:20::241]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 199FEC061574 for ; Tue, 11 May 2021 01:08:08 -0700 (PDT) Received: by mail-lj1-x241.google.com with SMTP id c15so9507284ljr.7 for ; Tue, 11 May 2021 01:08:08 -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=l8LjKeF7xUB1WD7WveY1VqJ0QLlpA02sBHv/Zc54oog=; b=tniuYKg1HguI2MQd2UejJnQwUTpyr6q2szB1Am0I2gAhT8o4BHN5w5Ep9j5jQoOyNZ EkOJ8Th2JRnkwjcnM9DvPlkN02rU1XhGwSQMps6iL0w3cmesRBqMsf94YGIogboDnEZ4 PvLwc8+Zs7+Rm9wBHq6l9hJL+5V+GpJMedpsPx2tDlDlsNrQrhcOQyXE6N++uc8vubQH FOo/SPFujQBja9AWehzvgwsBqDaCEQEKe3vBWWhGS1HpqkJCY/e0ywrqdWUsNaku2nlx S4/Gg565z/fP4+Ryl4a1s7qHvAik+gAzoYIzBoXnCfSg8LjVZ9f/dZVVjovnrgYCrttP ukDA== 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=l8LjKeF7xUB1WD7WveY1VqJ0QLlpA02sBHv/Zc54oog=; b=qzi2v2GM66nhPD6SGWt1jOw6TPvo8nkyWqGLMtEAfQmc23Le8zUJb7MH9CqSv3sNLB WUjiZXbCHa6C9v5l7F0f1njw7kjGedSXr1hIUU8awgIfPFeB7WOovoTMiu5xDZgsjwqW pubT5GVAOLEklzfyAEmixRBiIlrj8J/NAVEcGBaoqr4uyuwb+tXmGsfsT2nlW2EEyCCn Xo5ST75KYWpXN+LhHsjSIaRRdpuxRw46S1CSjkXJK7YkxFRgUSNgWvb7yP71NPxcrOlU rkaImI4Jlv1E1JypKFJTbdPZo1Y9nry0FUKmT3u7RebBNvEXVdhfnNjfq6mOvn97bcwj WiJA== X-Gm-Message-State: AOAM532iNHdJnPJ2u/mNHV/4he8+FeuioiDef2nQnSgXGZFe42dH2fcr +Wj0FO+q8dN6lMLRe5z6mDU= X-Google-Smtp-Source: ABdhPJzeOPZqYc68hKuZ2UZOFB2jpA3vwamDRKb0FMMAw+jCccrZtCHDimFakgxryNrYBJafo+GyHQ== X-Received: by 2002:a2e:8011:: with SMTP id j17mr20083882ljg.106.1620720486597; Tue, 11 May 2021 01:08:06 -0700 (PDT) Received: from eldfell ([194.136.85.206]) by smtp.gmail.com with ESMTPSA id c2sm2875304ljj.110.2021.05.11.01.08.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 11 May 2021 01:08:06 -0700 (PDT) Date: Tue, 11 May 2021 11:07:56 +0300 From: Pekka Paalanen To: Alex Deucher , Werner Sembach Cc: Dave Airlie , LKML , amd-gfx list , "Leo \(Sunpeng\) Li" , Maling list - DRI developers , "Deucher, Alexander" , Christian Koenig Subject: Re: [PATCH] drm/amd/display: Expose active display color configurations to userspace Message-ID: <20210511110756.7e754c30@eldfell> In-Reply-To: References: <20210507192718.35314-1-wse@tuxedocomputers.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; boundary="Sig_/HEwpQv.ZV+VGiXcatNUIIMr"; protocol="application/pgp-signature" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --Sig_/HEwpQv.ZV+VGiXcatNUIIMr Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Mon, 10 May 2021 17:47:01 -0400 Alex Deucher wrote: > On Fri, May 7, 2021 at 3:27 PM Werner Sembach w= rote: > > > > xrandr --prop and other userspace info tools have currently no way of > > telling which color configuration is used on HDMI and DP ports. > > > > The ongoing transsition from HDMI 1.4 to 2.0 and the different bandwidth > > requirements of YCbCr 4:2:0 and RGB color format raise different > > incompatibilities. Having these configuration information readily > > available is a useful tool in debuging washed out colors, color artefac= ts > > on small fonts and missing refreshrate options. =20 >=20 > I think we would ideally want these as generic connector properties > rather than AMD specific ones since they are not really AMD specific. > I believe there is already a generic drm property (max_bpc) for the > color depth. At this point, I think having a generic RGB vs YCbCr > property would make sense. I'm not sure about the color space. Hi, I believe that userspace will definitely want to know what exactly is going on on the monitor cable, so I think exposing more information is good, but I agree that it needs to be done with generic KMS properties as much as possible. Userspace is not going to bother having explicit code for driver-specific properties. I think a major use case will be Wayland color management, where a Wayland compositor will want to make sure that the video signal parameters have not changed since the monitor was last measured (profiled). If the signal configuration is different, the measured color profile may be invalid and therefore the end user needs to be warned. See some ideas in https://gitlab.freedesktop.org/wayland/weston/-/issues/467 under the heading "Color calibration auditing system". About the color space: is that something a kernel driver will decide on its own? I mean in the same sense as the driver will negotiate HDMI/DP link parameters, perhaps falling back to smaller requirements if higher requirements signal does not seem to work. We only need readback properties for things that generic userspace won't or cannot control explicitly, e.g. because the kernel driver has room to make a choice rather than fail. Thanks, pq --Sig_/HEwpQv.ZV+VGiXcatNUIIMr Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEJQjwWQChkWOYOIONI1/ltBGqqqcFAmCaO1wACgkQI1/ltBGq qqeF0A/7B6wXH1lcVQjMdfy0O2DC2PdZFUqoKmKJ44jPH2BH8MTFrvc/Bp1XPkcc Kj6HZL6VrmMnPxniVgqLZ7kH5xK8cw3SvAWBadcbJ5T6r27i+Q6BvefLCIFz9B06 GXKAFIQ6aCqaSqIRSSRqK8KYJ5Jz+fguAhfmCxK+Scd3arW8bwX/uLQnLvRmLr3K +8WhLFMzXRCNDOHCCSEqrT231uQyWzr1dBgXJ4BMl7Pz6MRF4U+VlJD2DoVez54c lOpPRBcpQ6Omt68JofVoQ/oxjzlIZpo5N3WSMYWKoikM8E3Tm/sd+acnsnXdFlKJ vofGNg6GaOUU4gCi1LZh9Bt9BwVRD8/qpcnJaOk2sX1+hLRcrPdl5zXXFTXkg0lY nwBRcAyBgooJOci/tFj0UugD7/EwHw9TxCZYLtw7d3CZfEtY90lJSO/ADNis3sFw X3EgLbTH591llu73BwFYUuQ7X1f/15OyBFrWOH/mpjeIZMSem8Q5nifiOxaXFw+J j3oTH8WCXLRm1LYOm+ushVQl57FUxVD/sSAdvgo4jwX6uO/s29Lp3h5TO5jKPneV siY2ycHLXPszJHxjT0dUKTgwgxD9AmLWW7SrYwnswSQZpqW07d2waK08SKjj+a1s 7HBBWQQeV71V/5f1HIws7SRNOddVqpbYgHyfKvJZA/y0fhQf8EY= =24IE -----END PGP SIGNATURE----- --Sig_/HEwpQv.ZV+VGiXcatNUIIMr-- 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=-2.0 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,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 E92D8C433B4 for ; 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Tue, 11 May 2021 01:08:06 -0700 (PDT) Received: from eldfell ([194.136.85.206]) by smtp.gmail.com with ESMTPSA id c2sm2875304ljj.110.2021.05.11.01.08.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 11 May 2021 01:08:06 -0700 (PDT) Date: Tue, 11 May 2021 11:07:56 +0300 From: Pekka Paalanen To: Alex Deucher , Werner Sembach Subject: Re: [PATCH] drm/amd/display: Expose active display color configurations to userspace Message-ID: <20210511110756.7e754c30@eldfell> In-Reply-To: References: <20210507192718.35314-1-wse@tuxedocomputers.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; boundary="Sig_/HEwpQv.ZV+VGiXcatNUIIMr"; protocol="application/pgp-signature" 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: Dave Airlie , LKML , Maling list - DRI developers , "Leo \(Sunpeng\) Li" , amd-gfx list , "Deucher, Alexander" , Christian Koenig Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" --Sig_/HEwpQv.ZV+VGiXcatNUIIMr Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Mon, 10 May 2021 17:47:01 -0400 Alex Deucher wrote: > On Fri, May 7, 2021 at 3:27 PM Werner Sembach w= rote: > > > > xrandr --prop and other userspace info tools have currently no way of > > telling which color configuration is used on HDMI and DP ports. > > > > The ongoing transsition from HDMI 1.4 to 2.0 and the different bandwidth > > requirements of YCbCr 4:2:0 and RGB color format raise different > > incompatibilities. Having these configuration information readily > > available is a useful tool in debuging washed out colors, color artefac= ts > > on small fonts and missing refreshrate options. =20 >=20 > I think we would ideally want these as generic connector properties > rather than AMD specific ones since they are not really AMD specific. > I believe there is already a generic drm property (max_bpc) for the > color depth. At this point, I think having a generic RGB vs YCbCr > property would make sense. I'm not sure about the color space. Hi, I believe that userspace will definitely want to know what exactly is going on on the monitor cable, so I think exposing more information is good, but I agree that it needs to be done with generic KMS properties as much as possible. Userspace is not going to bother having explicit code for driver-specific properties. I think a major use case will be Wayland color management, where a Wayland compositor will want to make sure that the video signal parameters have not changed since the monitor was last measured (profiled). If the signal configuration is different, the measured color profile may be invalid and therefore the end user needs to be warned. See some ideas in https://gitlab.freedesktop.org/wayland/weston/-/issues/467 under the heading "Color calibration auditing system". About the color space: is that something a kernel driver will decide on its own? I mean in the same sense as the driver will negotiate HDMI/DP link parameters, perhaps falling back to smaller requirements if higher requirements signal does not seem to work. We only need readback properties for things that generic userspace won't or cannot control explicitly, e.g. because the kernel driver has room to make a choice rather than fail. Thanks, pq --Sig_/HEwpQv.ZV+VGiXcatNUIIMr Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEJQjwWQChkWOYOIONI1/ltBGqqqcFAmCaO1wACgkQI1/ltBGq qqeF0A/7B6wXH1lcVQjMdfy0O2DC2PdZFUqoKmKJ44jPH2BH8MTFrvc/Bp1XPkcc Kj6HZL6VrmMnPxniVgqLZ7kH5xK8cw3SvAWBadcbJ5T6r27i+Q6BvefLCIFz9B06 GXKAFIQ6aCqaSqIRSSRqK8KYJ5Jz+fguAhfmCxK+Scd3arW8bwX/uLQnLvRmLr3K +8WhLFMzXRCNDOHCCSEqrT231uQyWzr1dBgXJ4BMl7Pz6MRF4U+VlJD2DoVez54c lOpPRBcpQ6Omt68JofVoQ/oxjzlIZpo5N3WSMYWKoikM8E3Tm/sd+acnsnXdFlKJ vofGNg6GaOUU4gCi1LZh9Bt9BwVRD8/qpcnJaOk2sX1+hLRcrPdl5zXXFTXkg0lY nwBRcAyBgooJOci/tFj0UugD7/EwHw9TxCZYLtw7d3CZfEtY90lJSO/ADNis3sFw X3EgLbTH591llu73BwFYUuQ7X1f/15OyBFrWOH/mpjeIZMSem8Q5nifiOxaXFw+J j3oTH8WCXLRm1LYOm+ushVQl57FUxVD/sSAdvgo4jwX6uO/s29Lp3h5TO5jKPneV siY2ycHLXPszJHxjT0dUKTgwgxD9AmLWW7SrYwnswSQZpqW07d2waK08SKjj+a1s 7HBBWQQeV71V/5f1HIws7SRNOddVqpbYgHyfKvJZA/y0fhQf8EY= =24IE -----END PGP SIGNATURE----- --Sig_/HEwpQv.ZV+VGiXcatNUIIMr-- 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=-2.0 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,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 2FEEAC433ED for ; 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Tue, 11 May 2021 01:08:06 -0700 (PDT) Received: from eldfell ([194.136.85.206]) by smtp.gmail.com with ESMTPSA id c2sm2875304ljj.110.2021.05.11.01.08.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 11 May 2021 01:08:06 -0700 (PDT) Date: Tue, 11 May 2021 11:07:56 +0300 From: Pekka Paalanen To: Alex Deucher , Werner Sembach Subject: Re: [PATCH] drm/amd/display: Expose active display color configurations to userspace Message-ID: <20210511110756.7e754c30@eldfell> In-Reply-To: References: <20210507192718.35314-1-wse@tuxedocomputers.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Dave Airlie , LKML , Maling list - DRI developers , "Leo \(Sunpeng\) Li" , amd-gfx list , "Deucher, Alexander" , Christian Koenig Content-Type: multipart/mixed; boundary="===============2017415010==" Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" --===============2017415010== Content-Type: multipart/signed; micalg=pgp-sha256; boundary="Sig_/HEwpQv.ZV+VGiXcatNUIIMr"; protocol="application/pgp-signature" --Sig_/HEwpQv.ZV+VGiXcatNUIIMr Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Mon, 10 May 2021 17:47:01 -0400 Alex Deucher wrote: > On Fri, May 7, 2021 at 3:27 PM Werner Sembach w= rote: > > > > xrandr --prop and other userspace info tools have currently no way of > > telling which color configuration is used on HDMI and DP ports. > > > > The ongoing transsition from HDMI 1.4 to 2.0 and the different bandwidth > > requirements of YCbCr 4:2:0 and RGB color format raise different > > incompatibilities. Having these configuration information readily > > available is a useful tool in debuging washed out colors, color artefac= ts > > on small fonts and missing refreshrate options. =20 >=20 > I think we would ideally want these as generic connector properties > rather than AMD specific ones since they are not really AMD specific. > I believe there is already a generic drm property (max_bpc) for the > color depth. At this point, I think having a generic RGB vs YCbCr > property would make sense. I'm not sure about the color space. Hi, I believe that userspace will definitely want to know what exactly is going on on the monitor cable, so I think exposing more information is good, but I agree that it needs to be done with generic KMS properties as much as possible. Userspace is not going to bother having explicit code for driver-specific properties. I think a major use case will be Wayland color management, where a Wayland compositor will want to make sure that the video signal parameters have not changed since the monitor was last measured (profiled). If the signal configuration is different, the measured color profile may be invalid and therefore the end user needs to be warned. See some ideas in https://gitlab.freedesktop.org/wayland/weston/-/issues/467 under the heading "Color calibration auditing system". About the color space: is that something a kernel driver will decide on its own? I mean in the same sense as the driver will negotiate HDMI/DP link parameters, perhaps falling back to smaller requirements if higher requirements signal does not seem to work. We only need readback properties for things that generic userspace won't or cannot control explicitly, e.g. because the kernel driver has room to make a choice rather than fail. Thanks, pq --Sig_/HEwpQv.ZV+VGiXcatNUIIMr Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEJQjwWQChkWOYOIONI1/ltBGqqqcFAmCaO1wACgkQI1/ltBGq qqeF0A/7B6wXH1lcVQjMdfy0O2DC2PdZFUqoKmKJ44jPH2BH8MTFrvc/Bp1XPkcc Kj6HZL6VrmMnPxniVgqLZ7kH5xK8cw3SvAWBadcbJ5T6r27i+Q6BvefLCIFz9B06 GXKAFIQ6aCqaSqIRSSRqK8KYJ5Jz+fguAhfmCxK+Scd3arW8bwX/uLQnLvRmLr3K +8WhLFMzXRCNDOHCCSEqrT231uQyWzr1dBgXJ4BMl7Pz6MRF4U+VlJD2DoVez54c lOpPRBcpQ6Omt68JofVoQ/oxjzlIZpo5N3WSMYWKoikM8E3Tm/sd+acnsnXdFlKJ vofGNg6GaOUU4gCi1LZh9Bt9BwVRD8/qpcnJaOk2sX1+hLRcrPdl5zXXFTXkg0lY nwBRcAyBgooJOci/tFj0UugD7/EwHw9TxCZYLtw7d3CZfEtY90lJSO/ADNis3sFw X3EgLbTH591llu73BwFYUuQ7X1f/15OyBFrWOH/mpjeIZMSem8Q5nifiOxaXFw+J j3oTH8WCXLRm1LYOm+ushVQl57FUxVD/sSAdvgo4jwX6uO/s29Lp3h5TO5jKPneV siY2ycHLXPszJHxjT0dUKTgwgxD9AmLWW7SrYwnswSQZpqW07d2waK08SKjj+a1s 7HBBWQQeV71V/5f1HIws7SRNOddVqpbYgHyfKvJZA/y0fhQf8EY= =24IE -----END PGP SIGNATURE----- --Sig_/HEwpQv.ZV+VGiXcatNUIIMr-- --===============2017415010== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx --===============2017415010==--