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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7489AC433F5 for ; Tue, 5 Oct 2021 17:33:19 +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 442316137C for ; Tue, 5 Oct 2021 17:33:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 442316137C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 774ED6EC12; Tue, 5 Oct 2021 17:33:18 +0000 (UTC) Received: from mail-oi1-x22d.google.com (mail-oi1-x22d.google.com [IPv6:2607:f8b0:4864:20::22d]) by gabe.freedesktop.org (Postfix) with ESMTPS id 716B06EC14 for ; Tue, 5 Oct 2021 17:33:17 +0000 (UTC) Received: by mail-oi1-x22d.google.com with SMTP id 24so361288oix.0 for ; Tue, 05 Oct 2021 10:33:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=71HyGq5jsXAg+sz6VrDwqjua1AYi4Yt0h0vLPVrLYyc=; b=VnWFO8feQ/jKEVNNYcCNDgAAFbjuPqav1DCKCE9RS6Bp1XdLPhtam4xcpTf/CpbsSc sinYpgamBHCflpT7bzw8WIfJEuxLdPEHmYh5wao0uqEsHHJ++9P/kORPaXtY8dmQK/El Ux06+7ABy1HOzZj/rOyETgeQkA65BgnrbBhzPw+CjK75rnN32pdEKiVj0rVK+VacAGq5 ZwLEa9IZ6fhtgVRR1hdLKPrT5OkI3XfbnQnlf/LZ0OmrqkSKWUuHXFaMFdO8+4dUJGmC fsmaRyXKuHdNnKr/WD6JJNWQsJyyl6XjVMU+F/3Zxjkh+2i/odHMHUnjQO+x4QhJIBGy MliA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=71HyGq5jsXAg+sz6VrDwqjua1AYi4Yt0h0vLPVrLYyc=; b=RjLjPk8CLpg55pGurB/z+008003WXtUbQ2YUYUENgAGDCKW+NrSrv4n5ZPkhebcImV wZOV/Kh33x5Ryjtaoz8BLUQZJ6BrsbbSYqQjHAQmJXf41rD9mYN7FanHdhGQaWBpNF9U unvBfa+g9OjYuYaqsWVhi1UJ4CDSP6UmqfmBju/gVuptMt3RM01HsNfxqXvsEyqbSdDi V0mLLaSkRKYtkfvpVPNPF7cnyG7zGRR9T6woN5UNADGzn2PNlUiYqgkt3kS+A40BjjKF 9KbRN5dm4KtzelQQzvXQ7pQTls4P9HBwK/mmb8PhLEZ9zsrfJx6jMpx2PhzGqfX0Wumr AvFw== X-Gm-Message-State: AOAM532epVo0k0lyesXFFJ4zjtPRBpWNo9epgysaK2QryC/qZDTUYqom 9NbwJiNIw/dFSBDHqwi4r3KU6Q== X-Google-Smtp-Source: ABdhPJxzcAx07ei8MxkmvHD51By4pDDo5yRTYN4AEghG3fL3svXbWySvfo7kHw+8THu/Opnn39LMDA== X-Received: by 2002:a05:6808:187:: with SMTP id w7mr3646625oic.140.1633455196519; Tue, 05 Oct 2021 10:33:16 -0700 (PDT) Received: from ripper ([2600:1700:a0:3dc8:205:1bff:fec0:b9b3]) by smtp.gmail.com with ESMTPSA id d4sm3664803oth.47.2021.10.05.10.33.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 05 Oct 2021 10:33:16 -0700 (PDT) Date: Tue, 5 Oct 2021 10:34:58 -0700 From: Bjorn Andersson To: Doug Anderson , Laurent Pinchart Cc: Rob Clark , Sean Paul , David Airlie , Daniel Vetter , linux-arm-msm , LKML , Abhinav Kumar , Stephen Boyd , Kuogee Hsieh , dri-devel , Vara Reddy , freedreno , Chandan Uddaraju Subject: Re: [RFC] drm/msm/dp: Allow attaching a drm_panel Message-ID: References: <20210726231351.655302-1-bjorn.andersson@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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" On Tue 05 Oct 08:39 PDT 2021, Doug Anderson wrote: > Hi, > > On Mon, Oct 4, 2021 at 6:09 PM Bjorn Andersson > wrote: > > > > On Mon 04 Oct 17:36 PDT 2021, Doug Anderson wrote: > > > > > Hi, > > > > > > On Fri, Oct 1, 2021 at 2:00 PM Bjorn Andersson > > > wrote: > > > > > > > > On Fri 27 Aug 13:52 PDT 2021, Doug Anderson wrote: > > > > > > > > > Hi, > > > > > > > > > > On Mon, Jul 26, 2021 at 4:15 PM Bjorn Andersson > > > > > wrote: > > > > > > > > > > > > +static int dp_parser_find_panel(struct dp_parser *parser) > > > > > > +{ > > > > > > + struct device_node *np = parser->pdev->dev.of_node; > > > > > > + int rc; > > > > > > + > > > > > > + rc = drm_of_find_panel_or_bridge(np, 2, 0, &parser->drm_panel, NULL); > > > > > > > > > > Why port 2? Shouldn't this just be port 1 always? The yaml says that > > > > > port 1 is "Output endpoint of the controller". We should just use port > > > > > 1 here, right? > > > > > > > > > > > > > Finally got back to this, changed it to 1 and figured out why I left it > > > > at 2. > > > > > > > > drm_of_find_panel_or_bridge() on a DP controller will find the of_graph > > > > reference to the USB-C controller, scan through the registered panels > > > > and conclude that the of_node of the USB-C controller isn't a registered > > > > panel and return -EPROBE_DEFER. > > > > > > I'm confused, but maybe it would help if I could see something > > > concrete. Is there a specific board this was happening on? > > > > > > > Right, let's make this more concrete with a snippet from the actual > > SC8180x DT. > > > > > Under the DP node in the device tree I expect: > > > > > > ports { > > > port@1 { > > > reg = <1>; > > > edp_out: endpoint { > > > remote-endpoint = <&edp_panel_in>; > > > }; > > > }; > > > }; > > > > > > > /* We got a panel */ > > panel { > > ... > > ports { > > port { > > auo_b133han05_in: endpoint { > > remote-endpoint = <&mdss_edp_out>; > > }; > > }; > > }; > > }; > > > > /* And a 2-port USB-C controller */ > > type-c-controller { > > ... > > connector@0 { > > ports { > > port@0 { > > reg = <0>; > > ucsi_port_0_dp: endpoint { > > remote-endpoint = <&dp0_mode>; > > }; > > }; > > > > port@1 { > > reg = <1>; > > ucsi_port_0_switch: endpoint { > > remote-endpoint = <&primary_qmp_phy>; > > }; > > }; > > }; > > }; > > > > connector@1 { > > ports { > > port@0 { > > reg = <0>; > > ucsi_port_1_dp: endpoint { > > remote-endpoint = <&dp1_mode>; > > }; > > }; > > > > port@1 { > > reg = <1>; > > ucsi_port_1_switch: endpoint { > > remote-endpoint = <&second_qmp_phy>; > > }; > > }; > > }; > > }; > > }; > > > > /* And then our 2 DP and single eDP controllers */ > > &mdss_dp0 { > > ports { > > port@1 { > > reg = <1>; > > dp0_mode: endpoint { > > remote-endpoint = <&ucsi_port_0_dp>; > > }; > > }; > > }; > > }; > > > > &mdss_dp1 { > > ports { > > port@1 { > > reg = <1>; > > dp1_mode: endpoint { > > remote-endpoint = <&ucsi_port_1_dp>; > > }; > > }; > > }; > > }; > > > > &mdss_edp { > > ports { > > port@1 { > > reg = <1>; > > mdss_edp_out: endpoint { > > remote-endpoint = <&auo_b133han05_in>; > > }; > > }; > > }; > > }; > > > > > If you have "port@1" pointing to a USB-C controller but this instance > > > of the DP controller is actually hooked up straight to a panel then > > > you should simply delete the "port@1" that points to the typeC and > > > replace it with one that points to a panel, right? > > > > > > > As you can see, port 1 on &mdss_dp0 and &mdss_dp1 points to the two UCSI > > connectors and the eDP points to the panel, exactly like we agreed. > > > > So now I call: > > drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &panel, NULL); > > > > which for the two DP nodes will pass respective UCSI connector to > > drm_find_panel() and get EPROBE_DEFER back - because they are not on > > panel_list. > > > > There's nothing indicating in the of_graph that the USB connectors > > aren't panels (or bridges), so I don't see a way to distinguish the two > > types remotes. > > As far as I can tell the way this would be solved would be to actually > pass &bridge in and then make sure that a bridge would be in place for > the DP connector. In the full DP case you'll get an -EPROBE_DEFER if > the connector hasn't been probed but once it's probed then it should > register as a bridge and thus give you the info you need (AKA that > this isn't a panel). > > I haven't done the digging to see how all this works, but according to > Laurent [1]: "Physical connectors are already handled as bridges, see > drivers/gpu/drm/bridge/display-connector.c" > All this seems to make sense for both eDP and "native" DP. > So basically I think this is solvable in code and there's no reason to > mess with the devicetree bindings to solve this problem. Does that > sound right? > But I don't have a DisplayPort connector. I have a USB-C connector, that upon determining that it's time to play DisplayPort will use the typec_mux abstraction to tell someone on the other side of the of_graph about DisplayPort events (HPD). So where would I put this drm_bridge in the USB-C case? I don't see that it fits in the Type-C side of things and putting it on the DP side would leave us with exactly the problem we have here. So we would have to put a fake "DP connector" inbetween the DP node and the Type-C controller? For reference, this is how I thought one is supposed to tie the Type-C controller to the display driver: https://lore.kernel.org/all/20211005022451.2037405-1-bjorn.andersson@linaro.org/ I'm afraid I must be missing something in Laurent and yours proposal (although I think Laurent is talking about the native DP case?). Regards, Bjorn > [1] https://lore.kernel.org/r/YUvMv+Y8tFcWPEHd@pendragon.ideasonboard.com/