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 0A4DEC433FE for ; Fri, 17 Dec 2021 11:00:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235193AbhLQLAH (ORCPT ); Fri, 17 Dec 2021 06:00:07 -0500 Received: from mga12.intel.com ([192.55.52.136]:26872 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235165AbhLQLAG (ORCPT ); Fri, 17 Dec 2021 06:00:06 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10200"; a="219746368" X-IronPort-AV: E=Sophos;i="5.88,213,1635231600"; d="scan'208";a="219746368" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Dec 2021 03:00:05 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,213,1635231600"; d="scan'208";a="662813875" Received: from mattu-haswell.fi.intel.com (HELO [10.237.72.199]) ([10.237.72.199]) by fmsmga001.fm.intel.com with ESMTP; 17 Dec 2021 03:00:03 -0800 To: Greg KH , Dave Hansen Cc: Lu Baolu , Peter Zijlstra , x86@kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, Chunfeng Yun References: <105f35d2-3c53-b550-bfb4-aa340d31128e@linux.intel.com> <88f466ff-a065-1e9a-4226-0abe2e71b686@linux.intel.com> <972a0e28-ad63-9766-88da-02743f80181b@intel.com> From: Mathias Nyman Subject: Re: earlyprintk=xdbc seems broken Message-ID: Date: Fri, 17 Dec 2021 13:01:43 +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: 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 17.29, Greg KH wrote: > On Fri, Dec 03, 2021 at 07:22:57AM -0800, Dave Hansen wrote: >> On 12/3/21 6:31 AM, Mathias Nyman wrote: >>>>> 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. >> >> Is someone at Intel responsible for this thing? get_maintainer.pl >> doesn't think so: >> >>> $ perl scripts/get_maintainer.pl ./drivers/usb/early/xhci-dbc.c >>> Greg Kroah-Hartman (supporter:USB SUBSYSTEM) >>> Mike Rapoport (commit_signer:1/1=100%,authored:1/1=100%,added_lines:5/5=100%,removed_lines:5/5=100%) >>> Andrew Morton (commit_signer:1/1=100%) >>> linux-usb@vger.kernel.org (open list:USB SUBSYSTEM) >>> linux-kernel@vger.kernel.org (open list) > > Intel is the only one that has this hardware :( > > I can reproduce this. Looks like problems started when driver converted to readl_poll_timeout_atomic() in: 796eed4b2342 usb: early: convert to readl_poll_timeout_atomic() Seems to hang when read_poll_timeout_atomic() calls ktime_* functions. Maybe it's too early for ktime. After reverting that patch it works again for me. -Mathias