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 7D164C43334 for ; Thu, 23 Jun 2022 19:08:35 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 5B50410E659; Thu, 23 Jun 2022 19:08:34 +0000 (UTC) Received: from mail-ot1-x329.google.com (mail-ot1-x329.google.com [IPv6:2607:f8b0:4864:20::329]) by gabe.freedesktop.org (Postfix) with ESMTPS id 10F8210E760 for ; Thu, 23 Jun 2022 19:08:33 +0000 (UTC) Received: by mail-ot1-x329.google.com with SMTP id l24-20020a0568301d7800b0060c1ebc6438so181442oti.9 for ; Thu, 23 Jun 2022 12:08:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:in-reply-to:references:from:user-agent:date:message-id :subject:to:cc; bh=G7GUFKx0kufkNV6cl0VJc529FkLJIKTxF3dZCCvrwdY=; b=iN0a13Zqsn8ttJ7ja/KPwL2wPvJTDmHPO333uxUAd1CAaE8rvuUZkbPDyN3+0gOYeh yFjnENL67HNFCTd3LjmuhZ4hhwqdRyCMALZc3RW5N1Org7VuzCf1DFMR5WtCyfv2391G uo55OZxLAmQCzfMdLjGN999g9b+vwqIJ9/3eM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:in-reply-to:references:from :user-agent:date:message-id:subject:to:cc; bh=G7GUFKx0kufkNV6cl0VJc529FkLJIKTxF3dZCCvrwdY=; b=Fj9cl+Cu+KW1gSZqzSj9PuzNwR0q4mo2J1xWGXx0+8BmAnHHPbw8UDuFnOi/mwu1Pf P4rlDH+QuYks32igv+kCq833QxUDKKT153vigN0jdMGtianNIxihw4OgpLS9YT8ZFWGR XetGeguR6ru69wI/XBgm4I/fyh1T5m+BLwpBZGKrXrvQ2hT9Zx/iqsp3N9CQQDh0XW3Y zrN+JN57DP9hH2kqPSZmgp0b3czt1kcwved3sGLmYANpgr/Mkt6pymc3elO1vHon7o56 R9cSkqaW9BB/jMS8cioK29AamndADtegQtMIO4iWlM5hDaZXDVy7FTxbswSzlCURorZZ cUow== X-Gm-Message-State: AJIora9xac58UcaIg4QtK8bX9AQ8MDovhcPwrgKyc/DZbTmh9f9KSyoE nhXJhw+/nmTj/WBpk1HyHHfT3t66Cnq61Oh5jmHMOA== X-Google-Smtp-Source: AGRyM1vgbF+x4e8hC812jkDhF5ujgwGy9u1TIoIP8891Q9B03Dipuo0gmMCNmbyza772yJuf+a8CoPoLp42FIFqFmzE= X-Received: by 2002:a9d:729b:0:b0:60c:21bd:97c0 with SMTP id t27-20020a9d729b000000b0060c21bd97c0mr4488368otj.77.1656011312243; Thu, 23 Jun 2022 12:08:32 -0700 (PDT) Received: from 753933720722 named unknown by gmailapi.google.com with HTTPREST; Thu, 23 Jun 2022 15:08:31 -0400 MIME-Version: 1.0 In-Reply-To: References: <20220622173605.1168416-1-pmalani@chromium.org> <20220622173605.1168416-7-pmalani@chromium.org> From: Stephen Boyd User-Agent: alot/0.10 Date: Thu, 23 Jun 2022 15:08:31 -0400 Message-ID: Subject: Re: [PATCH v5 6/9] dt/bindings: drm/bridge: it6505: Add mode-switch support To: Prashant Malani Content-Type: text/plain; charset="UTF-8" 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: heikki.krogerus@linux.intel.com, Andrzej Hajda , Neil Armstrong , David Airlie , dri-devel@lists.freedesktop.org, Laurent Pinchart , Krzysztof Kozlowski , Sam Ravnborg , Jernej Skrabec , devicetree@vger.kernel.org, Thomas Zimmermann , =?UTF-8?B?TsOtY29sYXMgRi4gUi4gQS4gUHJhZG8=?= , Jonas Karlman , Allen Chen , Pin-Yen Lin , Rob Herring , Maxime Ripard , Hsin-Yi Wang , Xin Ji , AngeloGioacchino Del Regno , Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Robert Foss , =?UTF-8?B?Sm9zw6kgRXhww7NzaXRv?= Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Quoting Prashant Malani (2022-06-23 11:37:08) > On Thu, Jun 23, 2022 at 11:24 AM Stephen Boyd wrote: > > > > Quoting Prashant Malani (2022-06-22 10:34:35) > > > From: Pin-Yen Lin > > > > > > ITE IT6505 can be used in systems to switch USB Type-C DisplayPort > > > alternate mode lane traffic between 2 Type-C ports. > > > > How does it work? From what I can tell from the information I find when > > googling this part[1] and looking at the existing binding doc is that > > this device is a DPI to DP bridge, and it outputs DP (probably 4 lanes > > of it?). Does the 2 type-c port design work by transmitting DP on two > > lanes of DP for one type-c port and another two lanes of DP for the > > other type-c port? > > > > DP could be one lane, so if this device is able to output one lane on > > any output differential pair then I suspect it could support 4 type-c > > ports if the hardware engineer connected it that way. Can you confirm my > > suspicion? > > I will let Pin-Yen comment re: this hardware, but 1-lane DP is not a > supported Type-C Pin assignment > (as per VESA DP Alternate Mode Spec version 2.0 [2]), so the H/W Some missing link? > configuration you are suggesting shouldn't be possible. > Alright, cool. But it is possible in the DP spec. So it seems like if this is connected to 4 DP connectors it could be used to mux between DP on 4 DP ports. 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C19FCCA480 for ; Thu, 23 Jun 2022 19:33:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231134AbiFWTdK (ORCPT ); Thu, 23 Jun 2022 15:33:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52364 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231617AbiFWTcU (ORCPT ); Thu, 23 Jun 2022 15:32:20 -0400 Received: from mail-ot1-x334.google.com (mail-ot1-x334.google.com [IPv6:2607:f8b0:4864:20::334]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C9C83F324 for ; Thu, 23 Jun 2022 12:08:33 -0700 (PDT) Received: by mail-ot1-x334.google.com with SMTP id 7-20020a9d0107000000b00616935dd045so196004otu.6 for ; Thu, 23 Jun 2022 12:08:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:in-reply-to:references:from:user-agent:date:message-id :subject:to:cc; bh=G7GUFKx0kufkNV6cl0VJc529FkLJIKTxF3dZCCvrwdY=; b=iN0a13Zqsn8ttJ7ja/KPwL2wPvJTDmHPO333uxUAd1CAaE8rvuUZkbPDyN3+0gOYeh yFjnENL67HNFCTd3LjmuhZ4hhwqdRyCMALZc3RW5N1Org7VuzCf1DFMR5WtCyfv2391G uo55OZxLAmQCzfMdLjGN999g9b+vwqIJ9/3eM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:in-reply-to:references:from :user-agent:date:message-id:subject:to:cc; bh=G7GUFKx0kufkNV6cl0VJc529FkLJIKTxF3dZCCvrwdY=; b=2Sat4grgXfVR0I4wCMY9AxRGBE7bizWYrm6gWu1lWj9Fkp2HUMqeMN06WTzII5MLGU lyyT8et4EoOrT4iHT7+/hWTDobutMtz67e2unxynxOgy6pLdCeSPn0nHLQONlDn6D3mr J69qFCO53H98rAhk2WcgLHPtXtHeqlngH6+HuzkNTTuhRLMc0lPvdfymnUrB5Fp/3Ed8 CPytvsEfJZqtZwldzONSrepHOuihADlyCo1GsKjw7bUCDtiPIjWWnG4bi9EZaa/KBPjn eBm9l06fJNXfSXP6qmi1DcyMUa+jaO+3osBKjZafHPVAW0E60tLXxi+GFAnnDafh2HDM FHPQ== X-Gm-Message-State: AJIora/+Y1YBs/Jk+l0YlqZ4QrWdy9E4WPsHzztwMqABFZyE0bksGLKi lRMWewVuwHIrIvTz6x6NMxGmz3WUf65f4jHu0hV3Qg== X-Google-Smtp-Source: AGRyM1vgbF+x4e8hC812jkDhF5ujgwGy9u1TIoIP8891Q9B03Dipuo0gmMCNmbyza772yJuf+a8CoPoLp42FIFqFmzE= X-Received: by 2002:a9d:729b:0:b0:60c:21bd:97c0 with SMTP id t27-20020a9d729b000000b0060c21bd97c0mr4488368otj.77.1656011312243; Thu, 23 Jun 2022 12:08:32 -0700 (PDT) Received: from 753933720722 named unknown by gmailapi.google.com with HTTPREST; Thu, 23 Jun 2022 15:08:31 -0400 MIME-Version: 1.0 In-Reply-To: References: <20220622173605.1168416-1-pmalani@chromium.org> <20220622173605.1168416-7-pmalani@chromium.org> From: Stephen Boyd User-Agent: alot/0.10 Date: Thu, 23 Jun 2022 15:08:31 -0400 Message-ID: Subject: Re: [PATCH v5 6/9] dt/bindings: drm/bridge: it6505: Add mode-switch support To: Prashant Malani Cc: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, bleung@chromium.org, heikki.krogerus@linux.intel.com, Pin-Yen Lin , Allen Chen , Andrzej Hajda , AngeloGioacchino Del Regno , Daniel Vetter , David Airlie , devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org, Greg Kroah-Hartman , Hsin-Yi Wang , Jernej Skrabec , Jonas Karlman , =?UTF-8?B?Sm9zw6kgRXhww7NzaXRv?= , Krzysztof Kozlowski , Laurent Pinchart , Maxime Ripard , Neil Armstrong , =?UTF-8?B?TsOtY29sYXMgRi4gUi4gQS4gUHJhZG8=?= , Robert Foss , Rob Herring , Sam Ravnborg , Thomas Zimmermann , Xin Ji Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Quoting Prashant Malani (2022-06-23 11:37:08) > On Thu, Jun 23, 2022 at 11:24 AM Stephen Boyd wrote: > > > > Quoting Prashant Malani (2022-06-22 10:34:35) > > > From: Pin-Yen Lin > > > > > > ITE IT6505 can be used in systems to switch USB Type-C DisplayPort > > > alternate mode lane traffic between 2 Type-C ports. > > > > How does it work? From what I can tell from the information I find when > > googling this part[1] and looking at the existing binding doc is that > > this device is a DPI to DP bridge, and it outputs DP (probably 4 lanes > > of it?). Does the 2 type-c port design work by transmitting DP on two > > lanes of DP for one type-c port and another two lanes of DP for the > > other type-c port? > > > > DP could be one lane, so if this device is able to output one lane on > > any output differential pair then I suspect it could support 4 type-c > > ports if the hardware engineer connected it that way. Can you confirm my > > suspicion? > > I will let Pin-Yen comment re: this hardware, but 1-lane DP is not a > supported Type-C Pin assignment > (as per VESA DP Alternate Mode Spec version 2.0 [2]), so the H/W Some missing link? > configuration you are suggesting shouldn't be possible. > Alright, cool. But it is possible in the DP spec. So it seems like if this is connected to 4 DP connectors it could be used to mux between DP on 4 DP ports.