From patchwork Mon May 14 13:27:52 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mathias Nyman X-Patchwork-Id: 10398475 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1DF9F6038F for ; Mon, 14 May 2018 13:25:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F342229051 for ; Mon, 14 May 2018 13:25:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E818C29080; Mon, 14 May 2018 13:25:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI,T_TVD_MIME_EPI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 437F029079 for ; Mon, 14 May 2018 13:25:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753556AbeENNZc (ORCPT ); Mon, 14 May 2018 09:25:32 -0400 Received: from mga07.intel.com ([134.134.136.100]:59476 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752366AbeENNZb (ORCPT ); Mon, 14 May 2018 09:25:31 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 May 2018 06:25:30 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,400,1520924400"; d="scan'208,223";a="199208470" Received: from mattu-haswell.fi.intel.com (HELO [10.237.72.164]) ([10.237.72.164]) by orsmga004.jf.intel.com with ESMTP; 14 May 2018 06:25:29 -0700 Subject: Re: Fwd: Enabling USB (auto)suspend for xHCI controllers incurs random device failures since kernel 4.15 To: gert , linux-usb@vger.kernel.org References: <1526056652.1037.1@disroot.org> From: Mathias Nyman Message-ID: <0f586dae-8af3-db03-d191-791f3f56b0c4@linux.intel.com> Date: Mon, 14 May 2018 16:27:52 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <1526056652.1037.1@disroot.org> Content-Language: en-US Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On 11.05.2018 19:37, gert wrote: > > Since the upgrade to Linux 4.15 (and also in 4.16), I'm experiencing an issue where all my USB devices just die seemingly without any cause. Both my laptop's internal (attached) keyboard as well as my external keyboard die. > > Replugging the external keyboard unfortunately does not solve the problem. My touchpad, on the other hand, continues to work, though it may internally be connected via PS/2. > > After this happens, I have only been able to solve it by rebooting. > > In the logs, the following error can be found. > > xhci_hcd 0000:3d:00.0: xHCI host controller not responding, assume dead > > Previously, similar issues occurred to users that could be fixed by adding intel_iommu=false to the kernel parameters. This however seems to be a different problem, as it newly occurs in this specific kernel version and is not solved by the aforementioned solution. > > This was also posted at the Archlinux forums [1], where we managed to pin down the issue to being related to xHCI and autosuspend (power management). I'm using powertop's --auto-tune and disabling the "good" setting for all xHCI controllers again makes the issue disappear. Linux 4.14 and lower also do not expose this issue. > > Please also find attached the complete journalctl output of one boot from start to finish that exposed the issue, which may be helpful during debugging. [1] > Hi I got a report about a very similar issue, thread can be found at: https://marc.info/?l=linux-usb&m=152335174903017&w=2 I didn't get any feedback about the suggested patch. If you can test it, either by just by compiling my for-usb-linus branch: git://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git for-usb-linus or alternatively applying the attached patch I would appreciate it. If it doesn't help then we need to dig deeper into it, woith more detailed logs. Thanks Mathias From d5fb6d354cd14d962d9f790f782ace0d06bf5002 Mon Sep 17 00:00:00 2001 From: Mathias Nyman Date: Fri, 4 May 2018 15:38:34 +0300 Subject: [PATCH] xhci: Fix perceived dead host due to runtime suspend race with event handler Don't rely on event interrupt (EINT) bit alone to detect pending port change in resume. If no change event is detected the host may be suspended again, oterwise roothubs are resumed. There is a lag in xHC setting EINT. If we don't notice the pending change in resume, and the controller is runtime suspeded again, it causes the event handler to assume host is dead as it will fail to read xHC registers once PCI puts the controller to D3 state. [ 268.520969] xhci_hcd: xhci_resume: starting port polling. [ 268.520985] xhci_hcd: xhci_hub_status_data: stopping port polling. [ 268.521030] xhci_hcd: xhci_suspend: stopping port polling. [ 268.521040] xhci_hcd: // Setting command ring address to 0x349bd001 [ 268.521139] xhci_hcd: Port Status Change Event for port 3 [ 268.521149] xhci_hcd: resume root hub [ 268.521163] xhci_hcd: port resume event for port 3 [ 268.521168] xhci_hcd: xHC is not running. [ 268.521174] xhci_hcd: handle_port_status: starting port polling. [ 268.596322] xhci_hcd: xhci_hc_died: xHCI host controller not responding, assume dead The EINT lag is described in a additional note in xhci specs 4.19.2: "Due to internal xHC scheduling and system delays, there will be a lag between a change bit being set and the Port Status Change Event that it generated being written to the Event Ring. If SW reads the PORTSC and sees a change bit set, there is no guarantee that the corresponding Port Status Change Event has already been written into the Event Ring." Signed-off-by: Mathias Nyman --- drivers/usb/host/xhci.c | 37 ++++++++++++++++++++++++++++++++++--- drivers/usb/host/xhci.h | 4 ++++ 2 files changed, 38 insertions(+), 3 deletions(-) diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 711da33..18e9fcf 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -844,6 +844,38 @@ static void xhci_disable_port_wake_on_bits(struct xhci_hcd *xhci) spin_unlock_irqrestore(&xhci->lock, flags); } +static bool xhci_pending_portevent(struct xhci_hcd *xhci) +{ + int port_index; + u32 status; + u32 portsc; + + status = readl(&xhci->op_regs->status); + if (status & STS_EINT) + return true; + /* + * Checking STS_EINT is not enough as there is a lag between a change + * bit being set and the Port Status Change Event that it generated + * being written to the Event Ring. See note in xhci 1.1 section 4.19.2. + */ + + port_index = xhci->num_usb2_ports; + while (port_index--) { + portsc = readl(xhci->usb2_ports[port_index]); + if (portsc & PORT_CHANGE_MASK || + (portsc & PORT_PLS_MASK) == XDEV_RESUME) + return true; + } + port_index = xhci->num_usb3_ports; + while (port_index--) { + portsc = readl(xhci->usb3_ports[port_index]); + if (portsc & PORT_CHANGE_MASK || + (portsc & PORT_PLS_MASK) == XDEV_RESUME) + return true; + } + return false; +} + /* * Stop HC (not bus-specific) * @@ -945,7 +977,7 @@ EXPORT_SYMBOL_GPL(xhci_suspend); */ int xhci_resume(struct xhci_hcd *xhci, bool hibernated) { - u32 command, temp = 0, status; + u32 command, temp = 0; struct usb_hcd *hcd = xhci_to_hcd(xhci); struct usb_hcd *secondary_hcd; int retval = 0; @@ -1069,8 +1101,7 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated) done: if (retval == 0) { /* Resume root hubs only when have pending events. */ - status = readl(&xhci->op_regs->status); - if (status & STS_EINT) { + if (xhci_pending_portevent(xhci)) { usb_hcd_resume_root_hub(xhci->shared_hcd); usb_hcd_resume_root_hub(hcd); } diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 6dfc486..9751c13 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -382,6 +382,10 @@ struct xhci_op_regs { #define PORT_PLC (1 << 22) /* port configure error change - port failed to configure its link partner */ #define PORT_CEC (1 << 23) +#define PORT_CHANGE_MASK (PORT_CSC | PORT_PEC | PORT_WRC | PORT_OCC | \ + PORT_RC | PORT_PLC | PORT_CEC) + + /* Cold Attach Status - xHC can set this bit to report device attached during * Sx state. Warm port reset should be perfomed to clear this bit and move port * to connected state. -- 2.7.4