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, 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 1D739C4361B for ; Tue, 8 Dec 2020 12:48:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DB0DD23A22 for ; Tue, 8 Dec 2020 12:48:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729336AbgLHMsl (ORCPT ); Tue, 8 Dec 2020 07:48:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50138 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726415AbgLHMsl (ORCPT ); Tue, 8 Dec 2020 07:48:41 -0500 Received: from mail-ej1-x641.google.com (mail-ej1-x641.google.com [IPv6:2a00:1450:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 181A4C061749 for ; Tue, 8 Dec 2020 04:48:01 -0800 (PST) Received: by mail-ej1-x641.google.com with SMTP id lt17so24465665ejb.3 for ; Tue, 08 Dec 2020 04:48:01 -0800 (PST) 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=NgHihUTd+8szXhbah4UFbE+y3fSYCEd9zdqGCjkaDzw=; b=WFWOF3V9cRyu2nIq5NK9+VZ+FAiNCr+N9FyT+rua3G5wp+KPE363LLgBXKWAbuBool ed13CAEv7+wQTsfNOZ5jct4HFDIFAGWV95iwrqMYEyBnHphDaNL31lVycYKizreIGeNX lgMW+nxZAICYvevTAUExrsFQp/gSP7GaCLmkpjNYgUqScbeP/ABa21DS+fooUWRaEiBY AOcBKNcXOUuFaN+Ux0i3Ghj8Wm+1DJXBWJk/YArCKyU4UwK+ovhzo4acyJ95k+NYpz5X 1DE5yUHzEoKCoUSSlJLMpiudN1A0ulWS1aowxrBmH6KTV8ke3oY2TFe4uR/OD0iGSOI0 9YPQ== 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=NgHihUTd+8szXhbah4UFbE+y3fSYCEd9zdqGCjkaDzw=; b=VQUPp1cfTZBFrNHkXV72UxytFy9x3TUVHo/VfgyuRzagtISdGQYl5YnuoHz9uFMLFw OShL8seoJvkximS28OBmMAUg+MeY9dLFZozu22OfMDtgMrhcfYcDzbMQDFJjagFeITAn A6FOMsZCjY87Zi3XIyyg0YP3gSNymOTpAonTMlo7LckLHWywdVlW6WY94by2/P+sItj1 jOKPK2uWrw0jTYaFjhZ/4lW4NYS15AybBEAmjeAd1nvaqVYhmTrFRHQ2iIgpPZYeAY+z HZccO6mZOG9znsszspWii9Xih2g9YwqE2UNdWh6j19/u85C3eWVUEjaVLnBtbTIg25X7 XQdw== X-Gm-Message-State: AOAM533jbzpOGNLWsjqoOfn39ksFmtHeroHhorNL+oIxvK32LvO6bYWN vUNDU3fxi4z0qZSbQ/k/qBE= X-Google-Smtp-Source: ABdhPJyfRsTDgoBEjiOtdymI2Zjr+9e60XqlWbIrOscHO+pCAfyo6AOUmP5fQApLQ03obglVJVhJsg== X-Received: by 2002:a17:906:c51:: with SMTP id t17mr23796267ejf.523.1607431679728; Tue, 08 Dec 2020 04:47:59 -0800 (PST) Received: from localhost ([62.96.65.119]) by smtp.gmail.com with ESMTPSA id pv24sm12507494ejb.101.2020.12.08.04.47.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Dec 2020 04:47:58 -0800 (PST) Date: Tue, 8 Dec 2020 13:47:56 +0100 From: Thierry Reding To: Bjorn Andersson Cc: Sam Ravnborg , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH] drm/panel: Make backlight attachment lazy Message-ID: References: <20201208044446.973238-1-bjorn.andersson@linaro.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="q/F3zxIokLeqOpPH" Content-Disposition: inline In-Reply-To: <20201208044446.973238-1-bjorn.andersson@linaro.org> User-Agent: Mutt/2.0.2 (d9268908) (2020-11-20) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --q/F3zxIokLeqOpPH Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Dec 07, 2020 at 10:44:46PM -0600, Bjorn Andersson wrote: > Some bridge chips, such as the TI SN65DSI86 DSI/eDP bridge, provides > means of generating a PWM signal for backlight control of the attached > panel. The provided PWM chip is typically controlled by the > pwm-backlight driver, which if tied to the panel will provide DPMS. >=20 > But with the current implementation the panel will refuse to probe > because the bridge driver has yet to probe and register the PWM chip, > and the bridge driver will refuse to probe because it's unable to find > the panel. What you're describing is basically a circular dependency. Can't we get rid of that in some other way? Why exactly does the bridge driver refuse to probe if the panel can't be found? In other words, I see how the bridge would /use/ the panel in that it forward a video stream to it. But how does the panel /use/ the bridge? Thierry --q/F3zxIokLeqOpPH Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAl/PdfoACgkQ3SOs138+ s6EFeQ/7BAokHQ30+o814DNtowr9AuLiWatODNQMti31IRlmkHjiTufMsqzMIdyc QEs6lj2pyv9pLS3kq7QVwsrViuPkRix+Fvn6BxN9aWeEqI5pbDMb3Jp4oGdCTt11 AvvA2bNXfgYKKXqVIOA36G/U/AKpAMvXSGsl8raUgar0pRp2Mp5G+y4tiLUCfJFN E1jLSBRJz0VnhazWFifRzCsAAOkZcirgZgcTOkOIxRoI3YjtpaMOkHfa1gPIpGJq DOJFXcFRasj6BocWtowGQn12fMyO+NFG6IrXzYZ1BNlCe5/ZCKgWXdXGOPexTfhn xMm4J0Ppshqr1pradhF3Hil7zRW65HrS1Ea8WcKuAjJOLFm3svYjR7Cwgd5TyPhD DIJlvWcFqmpgOxqbYMkemFLvBAVN5BPDhwpiu7w3Kg/1IRGRvMgp5JvbbRas2mvO Ddeths3bMPCX3yzVc6q65R9jcUNw5mMW60vy5TVbjguBgPt+4nYgDHUmSMEykPD5 vGL84/6DVzXwwKmKKq4BNJmWqcVbMW7DxlYJ51xZsW/NGrjgLStm/kThSMp0wB1y WmQM3sS1+DxUlPZuAUtAbUB6IyjXMqatDda0M5ySZ88HuCYebOYXV/rrnr8mIAiC IjSI6dzAANnqUt2KGNMP69MD4wZjS1qTND90QIM3ZlekbUk3Kqk= =BoBp -----END PGP SIGNATURE----- --q/F3zxIokLeqOpPH-- 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_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 E43B9C4361B for ; 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Tue, 08 Dec 2020 04:47:59 -0800 (PST) Received: from localhost ([62.96.65.119]) by smtp.gmail.com with ESMTPSA id pv24sm12507494ejb.101.2020.12.08.04.47.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Dec 2020 04:47:58 -0800 (PST) Date: Tue, 8 Dec 2020 13:47:56 +0100 From: Thierry Reding To: Bjorn Andersson Subject: Re: [RFC PATCH] drm/panel: Make backlight attachment lazy Message-ID: References: <20201208044446.973238-1-bjorn.andersson@linaro.org> MIME-Version: 1.0 In-Reply-To: <20201208044446.973238-1-bjorn.andersson@linaro.org> User-Agent: Mutt/2.0.2 (d9268908) (2020-11-20) 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: Thomas Zimmermann , David Airlie , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Sam Ravnborg Content-Type: multipart/mixed; boundary="===============1627552010==" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" --===============1627552010== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="q/F3zxIokLeqOpPH" Content-Disposition: inline --q/F3zxIokLeqOpPH Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Dec 07, 2020 at 10:44:46PM -0600, Bjorn Andersson wrote: > Some bridge chips, such as the TI SN65DSI86 DSI/eDP bridge, provides > means of generating a PWM signal for backlight control of the attached > panel. The provided PWM chip is typically controlled by the > pwm-backlight driver, which if tied to the panel will provide DPMS. >=20 > But with the current implementation the panel will refuse to probe > because the bridge driver has yet to probe and register the PWM chip, > and the bridge driver will refuse to probe because it's unable to find > the panel. What you're describing is basically a circular dependency. Can't we get rid of that in some other way? Why exactly does the bridge driver refuse to probe if the panel can't be found? In other words, I see how the bridge would /use/ the panel in that it forward a video stream to it. But how does the panel /use/ the bridge? Thierry --q/F3zxIokLeqOpPH Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAl/PdfoACgkQ3SOs138+ s6EFeQ/7BAokHQ30+o814DNtowr9AuLiWatODNQMti31IRlmkHjiTufMsqzMIdyc QEs6lj2pyv9pLS3kq7QVwsrViuPkRix+Fvn6BxN9aWeEqI5pbDMb3Jp4oGdCTt11 AvvA2bNXfgYKKXqVIOA36G/U/AKpAMvXSGsl8raUgar0pRp2Mp5G+y4tiLUCfJFN E1jLSBRJz0VnhazWFifRzCsAAOkZcirgZgcTOkOIxRoI3YjtpaMOkHfa1gPIpGJq DOJFXcFRasj6BocWtowGQn12fMyO+NFG6IrXzYZ1BNlCe5/ZCKgWXdXGOPexTfhn xMm4J0Ppshqr1pradhF3Hil7zRW65HrS1Ea8WcKuAjJOLFm3svYjR7Cwgd5TyPhD DIJlvWcFqmpgOxqbYMkemFLvBAVN5BPDhwpiu7w3Kg/1IRGRvMgp5JvbbRas2mvO Ddeths3bMPCX3yzVc6q65R9jcUNw5mMW60vy5TVbjguBgPt+4nYgDHUmSMEykPD5 vGL84/6DVzXwwKmKKq4BNJmWqcVbMW7DxlYJ51xZsW/NGrjgLStm/kThSMp0wB1y WmQM3sS1+DxUlPZuAUtAbUB6IyjXMqatDda0M5ySZ88HuCYebOYXV/rrnr8mIAiC IjSI6dzAANnqUt2KGNMP69MD4wZjS1qTND90QIM3ZlekbUk3Kqk= =BoBp -----END PGP SIGNATURE----- --q/F3zxIokLeqOpPH-- --===============1627552010== 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 --===============1627552010==--