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 9A4F6C433F5 for ; Tue, 25 Jan 2022 13:12:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1383792AbiAYNML (ORCPT ); Tue, 25 Jan 2022 08:12:11 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:20046 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1575474AbiAYNJs (ORCPT ); Tue, 25 Jan 2022 08:09:48 -0500 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 20PD5qpY018084; Tue, 25 Jan 2022 13:09:23 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : references : date : in-reply-to : message-id : mime-version : content-type; s=pp1; bh=DOwUVylm3hgoXpGtEI5hpuFUf0xRn2a+F5Eh8YQ5IkI=; b=Jzb2tem9WLKWqa1WbXwb/RXC7Pw6JXM8fita0ZDDsNPnv1BJG5unAtdPNxaj6YZHTFT/ OT9CnRD5tuJW+4QswNSy6gRt9DTU1D03m+ojNPPYql7IDUF70BZsOI8HolRQ8tDvUeyb 1nebrrkCjHMkBt32QGdsXIuwjInUbEI4jI4vN9drUSBqQrg53EeYXhpovxk1m/eVEa2T NXch1f9Qs549n2HxZwlFw0zxTRVrsbnRj9NBjVdMlEzSGCCrjmQW+6fuweG2Ib/AsJkW WhUPemjUn7N8giUIx4ymtYNaT2AJvtRULDO9An3eSvu6jtsVhB2n6/Xz7ND6dAx68Fn/ dQ== Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0b-001b2d01.pphosted.com with ESMTP id 3dthef8fdv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 25 Jan 2022 13:09:23 +0000 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 20PD3Poo018548; Tue, 25 Jan 2022 13:09:21 GMT Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by ppma04ams.nl.ibm.com with ESMTP id 3dr9j96an6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 25 Jan 2022 13:09:21 +0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 20PD9JI229164000 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 25 Jan 2022 13:09:19 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1F56811C04A; Tue, 25 Jan 2022 13:09:19 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CD78811C050; Tue, 25 Jan 2022 13:09:18 +0000 (GMT) Received: from tuxmaker.linux.ibm.com (unknown [9.152.85.9]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Tue, 25 Jan 2022 13:09:18 +0000 (GMT) From: Sven Schnelle To: Peter Zijlstra Cc: Mathias Nyman , Greg KH , Dave Hansen , Lu Baolu , x86@kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, Chunfeng Yun Subject: Re: earlyprintk=xdbc seems broken References: <88f466ff-a065-1e9a-4226-0abe2e71b686@linux.intel.com> <972a0e28-ad63-9766-88da-02743f80181b@intel.com> Date: Tue, 25 Jan 2022 14:09:18 +0100 In-Reply-To: (Peter Zijlstra's message of "Tue, 25 Jan 2022 13:45:50 +0100") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: _kYmxngVCR81fmKqNZ-dl-KA8w8WkKTk X-Proofpoint-GUID: _kYmxngVCR81fmKqNZ-dl-KA8w8WkKTk X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.816,Hydra:6.0.425,FMLib:17.11.62.513 definitions=2022-01-25_02,2022-01-25_01,2021-12-02_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 impostorscore=0 clxscore=1011 spamscore=0 malwarescore=0 bulkscore=0 lowpriorityscore=0 priorityscore=1501 mlxscore=0 mlxlogscore=947 adultscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2201110000 definitions=main-2201250085 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Peter Zijlstra writes: > 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. Stupid beginners question: Would every USB3 A-A cable work, or are the debug cables special? I've read the RX/TX pairs have to be swapped, but to me it looks like that's always the case? I'm just asking because i tried to debug a before-framebuffer crash on my Thinkpad X1, but didn't have any luck getting xdbc running. Maybe because of the bug above. Would be nice if someone could confirm whether that should work with every USB3 A-A cable. Thanks, Sven