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 16E75C433EF for ; Fri, 3 Dec 2021 14:30:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1381478AbhLCOdi (ORCPT ); Fri, 3 Dec 2021 09:33:38 -0500 Received: from mga07.intel.com ([134.134.136.100]:54386 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232082AbhLCOdd (ORCPT ); Fri, 3 Dec 2021 09:33:33 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10186"; a="300365903" X-IronPort-AV: E=Sophos;i="5.87,284,1631602800"; d="scan'208";a="300365903" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Dec 2021 06:30:08 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,284,1631602800"; d="scan'208";a="656096289" Received: from mattu-haswell.fi.intel.com (HELO [10.237.72.199]) ([10.237.72.199]) by fmsmga001.fm.intel.com with ESMTP; 03 Dec 2021 06:30:06 -0800 Subject: Re: earlyprintk=xdbc seems broken To: Lu Baolu , Peter Zijlstra Cc: x86@kernel.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org References: <105f35d2-3c53-b550-bfb4-aa340d31128e@linux.intel.com> From: Mathias Nyman Message-ID: <88f466ff-a065-1e9a-4226-0abe2e71b686@linux.intel.com> Date: Fri, 3 Dec 2021 16:31:42 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <105f35d2-3c53-b550-bfb4-aa340d31128e@linux.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3.12.2021 2.52, Lu Baolu wrote: > Hi Peter, > > On 12/2/21 11:22 PM, Peter Zijlstra wrote: >> Hi Lu, >> >> I was unfortunate enough to need xdbc and can't get my machine to boot >> with earlyprintk=xdbc on the cmdline. >> >> When I boot the target without the earlyprintk=xdbc, but have the cable >> attached, it won't boot because boot gets stuck like: >> >> Dec  2 15:08:10 tigerlake kernel: [   42.043137] usb usb4-port3: Cannot enable. Maybe the USB cable is bad? >> Dec  2 15:08:10 tigerlake kernel: [   42.043227] usb usb4-port3: config error >> >> However, when I boot without earlyprintk=xdbc, without the cable >> attached, then I can attach the cable and: >> >> $ echo enable > /sys/bus/pci/devices/0000:00:14.0/dbc >> >> will actually work, and it shows up on my host system: >> >> [1023855.419430] usb usb2-port3: Cannot enable. Maybe the USB cable is bad? >> [1023855.419455] usb usb2-port3: config error >> [1023859.491476] usb usb2-port3: Cannot enable. Maybe the USB cable is bad? >> [1023859.491487] usb usb2-port3: config error >> [1023861.335436] usb usb2-port3: config error >> [1023861.607476] usb 2-3: new SuperSpeed USB device number 7 using xhci_hcd >> [1023861.627614] usb 2-3: LPM exit latency is zeroed, disabling LPM. >> [1023861.627853] usb 2-3: New USB device found, idVendor=1d6b, idProduct=0010, bcdDevice= 0.10 >> [1023861.627855] usb 2-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3 >> [1023861.627856] usb 2-3: Product: Linux USB Debug Target >> [1023861.627857] usb 2-3: Manufacturer: Linux Foundation >> [1023861.627858] usb 2-3: SerialNumber: 0001 >> [1023861.629344] usb_debug 2-3:1.0: xhci_dbc converter detected >> [1023861.629532] usb 2-3: xhci_dbc converter now attached to ttyUSB0 >> >> >> Can you please see if you can repro and fix this? >> >> This all was with current 5.16-rc3 on a tigerlake nuc. >> >> Also, perhaps you can update the guide on what sort of setup/cables >> etc.. you need when either the host or the client is a usb3.1 usb-c only >> device. >> > > + Mathias, maybe he still has a USB 3.0 debugging cable. > Should have at the office, I'll pick it up next week and try it out. -Mathias