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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 14803C2D0D1 for ; Thu, 19 Dec 2019 18:51:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DCBED2064B for ; Thu, 19 Dec 2019 18:51:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576781476; bh=Pb9ciWE7BhqDKqGciFvETrPxdloWHMdXD7raHOQIW/0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=q2LzBsFTvmHnQe6yxLho7fs1o8o00KCJAbomo7f6Sy2HftlfI2VdugTyoTAVNMcom LBDJlPHRN1bkhIsn4b2AHMcJ1NCjNr/bW1p8fRwQNx9ltZNu/yX9CPaP3vMY1RMl8D 0X4Jw5dFL15YDn5aQAtSQlm3mlolndB9cMppuQGk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730122AbfLSSvP (ORCPT ); Thu, 19 Dec 2019 13:51:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:45372 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727497AbfLSSvK (ORCPT ); Thu, 19 Dec 2019 13:51:10 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CCC1724682; Thu, 19 Dec 2019 18:51:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576781469; bh=Pb9ciWE7BhqDKqGciFvETrPxdloWHMdXD7raHOQIW/0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fhIR04bdFAEvTMUs9mNyWkfOY2rF4F29oxq/5TQDbWWS03QL+tvumtkzwiACV8n8l wS+ew36FQEWbr4qujWzJBhcBUPEoK/jMZaeHEsMr8xnorpLLDoaATjTmQ/fafKPUf8 leHhNj1k6b5o1wg9yiBqc2tyOfaq3YoAacJioGVE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Lee, Hou-hsun" , "Lee, Chiasheng" , Mathias Nyman , Lee@vger.kernel.org Subject: [PATCH 4.14 34/36] xhci: fix USB3 device initiated resume race with roothub autosuspend Date: Thu, 19 Dec 2019 19:34:51 +0100 Message-Id: <20191219182926.614880725@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191219182848.708141124@linuxfoundation.org> References: <20191219182848.708141124@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mathias Nyman commit 057d476fff778f1d3b9f861fdb5437ea1a3cfc99 upstream. A race in xhci USB3 remote wake handling may force device back to suspend after it initiated resume siganaling, causing a missed resume event or warm reset of device. When a USB3 link completes resume signaling and goes to enabled (UO) state a interrupt is issued and the interrupt handler will clear the bus_state->port_remote_wakeup resume flag, allowing bus suspend. If the USB3 roothub thread just finished reading port status before the interrupt, finding ports still in suspended (U3) state, but hasn't yet started suspending the hub, then the xhci interrupt handler will clear the flag that prevented roothub suspend and allow bus to suspend, forcing all port links back to suspended (U3) state. Example case: usb_runtime_suspend() # because all ports still show suspended U3 usb_suspend_both() hub_suspend(); # successful as hub->wakeup_bits not set yet ==> INTERRUPT xhci_irq() handle_port_status() clear bus_state->port_remote_wakeup usb_wakeup_notification() sets hub->wakeup_bits; kick_hub_wq() <== END INTERRUPT hcd_bus_suspend() xhci_bus_suspend() # success as port_remote_wakeup bits cleared Fix this by increasing roothub usage count during port resume to prevent roothub autosuspend, and by making sure bus_state->port_remote_wakeup flag is only cleared after resume completion is visible, i.e. after xhci roothub returned U0 or other non-U3 link state link on a get port status request. Issue rootcaused by Chiasheng Lee Cc: Cc: Lee, Hou-hsun Reported-by: Lee, Chiasheng Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/20191211142007.8847-3-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-hub.c | 8 ++++++++ drivers/usb/host/xhci-ring.c | 6 +----- 2 files changed, 9 insertions(+), 5 deletions(-) --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -887,6 +887,14 @@ static u32 xhci_get_port_status(struct u status |= USB_PORT_STAT_C_BH_RESET << 16; if ((raw_port_status & PORT_CEC)) status |= USB_PORT_STAT_C_CONFIG_ERROR << 16; + + /* USB3 remote wake resume signaling completed */ + if (bus_state->port_remote_wakeup & (1 << wIndex) && + (raw_port_status & PORT_PLS_MASK) != XDEV_RESUME && + (raw_port_status & PORT_PLS_MASK) != XDEV_RECOVERY) { + bus_state->port_remote_wakeup &= ~(1 << wIndex); + usb_hcd_end_port_resume(&hcd->self, wIndex); + } } if (hcd->speed < HCD_USB3) { --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1679,9 +1679,6 @@ static void handle_port_status(struct xh usb_hcd_resume_root_hub(hcd); } - if (hcd->speed >= HCD_USB3 && (portsc & PORT_PLS_MASK) == XDEV_INACTIVE) - bus_state->port_remote_wakeup &= ~(1 << faked_port_index); - if ((portsc & PORT_PLC) && (portsc & PORT_PLS_MASK) == XDEV_RESUME) { xhci_dbg(xhci, "port resume event for port %d\n", port_id); @@ -1700,6 +1697,7 @@ static void handle_port_status(struct xh bus_state->port_remote_wakeup |= 1 << faked_port_index; xhci_test_and_clear_bit(xhci, port_array, faked_port_index, PORT_PLC); + usb_hcd_start_port_resume(&hcd->self, faked_port_index); xhci_set_link_state(xhci, port_array, faked_port_index, XDEV_U0); /* Need to wait until the next link state change @@ -1737,8 +1735,6 @@ static void handle_port_status(struct xh if (slot_id && xhci->devs[slot_id]) xhci_ring_device(xhci, slot_id); if (bus_state->port_remote_wakeup & (1 << faked_port_index)) { - bus_state->port_remote_wakeup &= - ~(1 << faked_port_index); xhci_test_and_clear_bit(xhci, port_array, faked_port_index, PORT_PLC); usb_wakeup_notification(hcd->self.root_hub,