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 00264C433F5 for ; Tue, 25 Jan 2022 19:40:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230283AbiAYTkI (ORCPT ); Tue, 25 Jan 2022 14:40:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53162 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230222AbiAYTkH (ORCPT ); Tue, 25 Jan 2022 14:40:07 -0500 Received: from mail-lf1-x12b.google.com (mail-lf1-x12b.google.com [IPv6:2a00:1450:4864:20::12b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B1FC6C061744; Tue, 25 Jan 2022 11:40:03 -0800 (PST) Received: by mail-lf1-x12b.google.com with SMTP id n8so18399019lfq.4; Tue, 25 Jan 2022 11:40:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Tduuesxq4hZpsXCln7SUx3iQzE99K3TTjs0yDxRG/Yw=; b=YaZ1s4EOfT/xURCNUJ7ljTeO1+Sr8ERLBWB+TaU8n79uLP5u7yXPf8XBygAD4VQsNH J4jM8g1svCtsX0kW47011E2cKo8RUb68yYpRoqxTysQMoI9YspjrV3XO0B7J4E8vY6OW enFoqoe7lU1TKO1sFS+KpPLDlsaR7aRd4iTR7BkJ44c11APqRS03TRLMQkPZuT3CMrkI q5Hu8Sd1XAqi8gGruEIz35uHhEk/i+/yKnoP5qjwaEqS5VL5hyiw8lwSfCEF/7SqL62l 7y3z8h1MuuuvbVXWvYZrLFxgKLC5O9Plt5ybxYZ2arFtsmTf54f+TbLzl0kakgeZzi2N cL7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Tduuesxq4hZpsXCln7SUx3iQzE99K3TTjs0yDxRG/Yw=; b=j++Zxw7Y/lPpiPOglDI5aZM+ok4W3YWBof0Fz2qcGaUuBmSzYpdKS2+2MfueaMBEGs ZnmHxfSyrX8CxhCQGTHVebSghDCiiCyUpocuqVQIT85Y4i/ZLJyRLHJhEN/86HZzmdZx ACCYwgyRy/EwfC6h4AbeX4THGcAn1HeUPMCs229Fss6AHqbNosSXSlTf1DXVteqRZygC trfG3hjsywqq7fB/fXmYNsy9w4Ark+SZe3NnEsjEtcoOrOX2Yk3kpQgNmKa7E2dZ+3aC tNXISGGg8j+VlZDC7dqx2gzPcuIwa0NjHl3LgdNhwzMAcSLNH7VZpoZNgtbMNRNEaWlV UU1g== X-Gm-Message-State: AOAM531YV/IRaM7cunMJkpMm1Sbm43zmwQutw3HkYduBXrZ79qp1ZSxp gnFCSwdx7SMExpPu5uudrSK3AwkZ0eUi/78cPTQ= X-Google-Smtp-Source: ABdhPJwA25TgpbVOGFVpZkvzEypgG/YO9KRxt83JO8OsOWlZcjrL0PjPaf+E1o/Y8FngcqRhLtO/opJOvONyjKMbJdA= X-Received: by 2002:a19:4945:: with SMTP id l5mr17220627lfj.595.1643139601812; Tue, 25 Jan 2022 11:40:01 -0800 (PST) MIME-Version: 1.0 References: <88f466ff-a065-1e9a-4226-0abe2e71b686@linux.intel.com> <972a0e28-ad63-9766-88da-02743f80181b@intel.com> In-Reply-To: From: Rajaram R Date: Wed, 26 Jan 2022 01:09:49 +0530 Message-ID: Subject: Re: earlyprintk=xdbc seems broken To: Peter Zijlstra Cc: Mathias Nyman , Greg KH , Dave Hansen , Lu Baolu , x86@kernel.org, LKML , linux-usb@vger.kernel.org, Chunfeng Yun Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 26, 2022 at 12:11 AM Peter Zijlstra wrote: > > On Mon, Jan 24, 2022 at 04:55:22PM +0200, Mathias Nyman wrote: > > > > > [ 0.000000] xhci_dbc:early_xdbc_parse_parameter: dbgp_num: 0 > > > [ 4.984106] xhci_dbc:xdbc_start: waiting for connection timed out, DCPORTSC:0xa0 > > > [ 9.946159] xhci_dbc:xdbc_start: waiting for connection timed out, DCPORTSC:0xa0 > > > [ 9.946163] xhci_dbc:early_xdbc_setup_hardware: failed to setup the connection to host > > > > > > [ 12.818364] xhci_hcd 0000:00:0d.0: xHCI Host Controller > > > [ 12.818373] xhci_hcd 0000:00:0d.0: new USB bus registered, assigned bus number 1 > > > [ 12.820360] xhci_hcd 0000:00:0d.0: xHCI Host Controller > > > [ 12.820363] xhci_hcd 0000:00:0d.0: new USB bus registered, assigned bus number 2 > > > [ 12.821036] xhci_hcd 0000:00:14.0: xHCI Host Controller > > > [ 12.821040] xhci_hcd 0000:00:14.0: new USB bus registered, assigned bus number 3 > > > [ 12.823451] xhci_hcd 0000:00:14.0: xHCI Host Controller > > > [ 12.823453] xhci_hcd 0000:00:14.0: new USB bus registered, assigned bus number 4 > > > [ 17.115089] usb usb4-port4: Cannot enable. Maybe the USB cable is bad? > > > [ 17.115163] usb usb4-port4: config error > > > > Ok, I see it now. > > Your setup has two xhci controllers, earlypringk=dbc enables dbc on the first xhci > > it finds, which would be at 0000:00:0d.0. > > Your cable is connected to the second xhci host at 0000:00:14.0 > > I suspect the first xhci controller is for the usb-c ports on the > machine, while the second one has the usb-a ports covered. > > Now the documentation states we need this super speed A<->A cable, but > could you also update the documentation for usb-c ? There's a fair > number of usb-c only devices out there now. > > C<->A and C<->C cables are fairly easy to come by, would they 'just > work' ? I have used DbC with USB-C to A and it works