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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 44A8DCAC5B5 for ; Sun, 28 Sep 2025 09:53:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=UkVxvqY47BVfvtfrfxhiRV0lcWag2/777S8SX2eA3Co=; b=wQlg0YVYQ9ey4i V55xi2sVzS3FSyUmO14FZXVATShUGJ8t92Ix1HuGXMMTcsyIdpr3JOK3Zx77TbQakNtGoZ1tyvUic w5q5R7UX5wJUsK7tcik0kn+DAM54C1eg0BH5lvm4PrulNV0b8/jLRPnEiCseTcBkAiSXDRn7+d7Rr Y//96JNZVPmfXhZzO64+H2KpEtkTNvX9rAPsawrfj2wQ3e52OsXbOjA/W6yeR8V5ZVauMz1ktkHs6 9ojE72LEnUODPXW9dai3KuonZwfhOD2I4Dsu4pFW5+eYznzvkVmHnOqgQ8s3HMGgKbfuUo+R+O0OU xJxj6VGwXtsKCdtviffQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1v2o5M-0000000Emmq-0QW9; Sun, 28 Sep 2025 09:52:52 +0000 Received: from mail-m3299.qiye.163.com ([220.197.32.99]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1v2o5J-0000000EmiW-1x0R; Sun, 28 Sep 2025 09:52:50 +0000 Received: from [172.16.12.153] (unknown [58.22.7.114]) by smtp.qiye.163.com (Hmail) with ESMTP id 2455d07b1; Sun, 28 Sep 2025 17:52:36 +0800 (GMT+08:00) Message-ID: Date: Sun, 28 Sep 2025 17:52:35 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 5/7] drm/rockchip: cdn-dp: Add multiple bridges to support PHY port selection To: Dmitry Baryshkov , Chaoyi Chen Cc: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Vinod Koul , Kishon Vijay Abraham I , Heiko Stuebner , Sandy Huang , Andy Yan , Yubing Zhang , Frank Wang , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Amit Sunil Dhamne , Heikki Krogerus , Greg Kroah-Hartman , Dragan Simic , Johan Jonker , Diederik de Haas , Peter Robinson , linux-usb@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-phy@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, dri-devel@lists.freedesktop.org References: <20250922012039.323-1-kernel@airkyi.com> <20250922012039.323-6-kernel@airkyi.com> Content-Language: en-US From: Chaoyi Chen In-Reply-To: X-HM-Tid: 0a998fbd11a503abkunma2c1ce0f943b8a X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFDSUNOT01LS0k3V1ktWUFJV1kPCRoVCBIfWUFZGhlLGlZNSk0YGE9JTx5PGkNWFRQJFh oXVRMBExYaEhckFA4PWVdZGBILWUFZTkNVSUlVTFVKSk9ZV1kWGg8SFR0UWUFZT0tIVUpLSEpPSE xVSktLVUpCS0tZBg++ DKIM-Signature: a=rsa-sha256; b=fkmaC9JhLsx9ypREA2gyK2saMIt0xQXv11bYSJmDDFFpI7xmfpCJWCu/QwNzs8iObZJwhYNAOBXT0AKdgryMB/HWPPuwHP4cE9dr6FPYq6oyYCBt+9FMdhF+19j6+JMmlgQdJWNrnY2U734Idzqo3Sisf0O1F72QkVhyE4zITHI=; s=default; c=relaxed/relaxed; d=rock-chips.com; v=1; bh=r6bywD2WUzTYm4ELUvERid8tPQSU5/IWu32J6FLL1ok=; h=date:mime-version:subject:message-id:from; X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250928_025249_676943_0F27A89C X-CRM114-Status: GOOD ( 12.00 ) X-BeenThere: linux-rockchip@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Upstream kernel work for Rockchip platforms List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+linux-rockchip=archiver.kernel.org@lists.infradead.org On 9/23/2025 9:50 AM, Dmitry Baryshkov wrote: [...] >> + /* One endpoint may correspond to one HPD bridge. */ >> + for_each_of_graph_port_endpoint(port, dp_ep) { >> + /* Try to get "port" node of correspond PHY device */ >> + struct device_node *phy_ep __free(device_node) = >> + of_graph_get_remote_endpoint(dp_ep); >> + struct device_node *phy_port __free(device_node) = >> + of_get_parent(phy_ep); >> + >> + if (!phy_port) { >> + continue; >> + } >> + >> + /* >> + * A PHY port may contain two endpoints: USB connector port or CDN-DP port. >> + * Try to find the node of USB connector. > And then there can be a retimer between PHY and the USB-C connector. Or > some signal MUX. Or DP-to-HDMI bridge. Please, don't parse DT for other > devices. Instead you can add drm_aux_bridge to your PHY and let DRM core > build the bridge chain following OF graph. > I think building a bridge chain across multiple drm_aux_hpd_bridge may be difficult. First, drm_dp_hpd_bridge_register() cannot register the bridge immediately; instead, it is deferred until drm_aux_hpd_bridge_probe(). When it is added to the bridge_list, it may not yet be attached, and attempting to attach it at that point is too late. But, if I only use drm_aux_bridge on the USB-C connector, and use my own custom bridge on the PHY device and managing the alloc and attach bridge process myself, then things would become much easier. -- Best, Chaoyi _______________________________________________ Linux-rockchip mailing list Linux-rockchip@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-rockchip