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=unavailable 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 6C89DC3F68F for ; Wed, 22 Jan 2020 09:48:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 41B7F24696 for ; Wed, 22 Jan 2020 09:48:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579686505; bh=8iKCH8IAoIVqYSF1DDtgGAo7icbGUKFCDo3jdr2rTI0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tTt1NeQFzJfVZ6fOnZZ4pk4h29Iy9c/Imiv2J+CLE3A6bYvtMuNGUeEFHQZRoex31 QCVQEW0sd5wsh0fPXPilFvWgqgKsBOew9xhhxBDNMU7cnSFLmoc+HkXGGfMcVv7Tce uct0GqRLCRXVUwPM5pjI6KzI3sB1bVKyX8lotXRw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387555AbgAVJlT (ORCPT ); Wed, 22 Jan 2020 04:41:19 -0500 Received: from mail.kernel.org ([198.145.29.99]:60478 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387413AbgAVJlL (ORCPT ); Wed, 22 Jan 2020 04:41:11 -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 3FA1324680; Wed, 22 Jan 2020 09:41:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579686070; bh=8iKCH8IAoIVqYSF1DDtgGAo7icbGUKFCDo3jdr2rTI0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ky+tB8PKdWyySIK5b2K///geo0qUo78XFA3VSllULwrEq0vS2G7vWD/sVEWLGNCAy 93jjjfJZuL31aggfqd6+vGvkivDegeHn6W+uMyb464y95ggKIlkRsCFWkemnYQ9fZ6 wB3qh8rwFqGtBmsUAWfEHHv0yL04a3+kuCloppxg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Keiya Nobuta , Alan Stern Subject: [PATCH 4.19 032/103] usb: core: hub: Improved device recognition on remote wakeup Date: Wed, 22 Jan 2020 10:28:48 +0100 Message-Id: <20200122092808.666059128@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200122092803.587683021@linuxfoundation.org> References: <20200122092803.587683021@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: Keiya Nobuta commit 9c06ac4c83df6d6fbdbf7488fbad822b4002ba19 upstream. If hub_activate() is called before D+ has stabilized after remote wakeup, the following situation might occur: __ ___________________ / \ / D+ __/ \__/ Hub _______________________________ | ^ ^ ^ | | | | Host _____v__|___|___________|______ | | | | | | | \-- Interrupt Transfer (*3) | | \-- ClearPortFeature (*2) | \-- GetPortStatus (*1) \-- Host detects remote wakeup - D+ goes high, Host starts running by remote wakeup - D+ is not stable, goes low - Host requests GetPortStatus at (*1) and gets the following hub status: - Current Connect Status bit is 0 - Connect Status Change bit is 1 - D+ stabilizes, goes high - Host requests ClearPortFeature and thus Connect Status Change bit is cleared at (*2) - After waiting 100 ms, Host starts the Interrupt Transfer at (*3) - Since the Connect Status Change bit is 0, Hub returns NAK. In this case, port_event() is not called in hub_event() and Host cannot recognize device. To solve this issue, flag change_bits even if only Connect Status Change bit is 1 when got in the first GetPortStatus. This issue occurs rarely because it only if D+ changes during a very short time between GetPortStatus and ClearPortFeature. However, it is fatal if it occurs in embedded system. Signed-off-by: Keiya Nobuta Cc: stable Acked-by: Alan Stern Link: https://lore.kernel.org/r/20200109051448.28150-1-nobuta.keiya@fujitsu.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hub.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -1165,6 +1165,7 @@ static void hub_activate(struct usb_hub * PORT_OVER_CURRENT is not. So check for any of them. */ if (udev || (portstatus & USB_PORT_STAT_CONNECTION) || + (portchange & USB_PORT_STAT_C_CONNECTION) || (portstatus & USB_PORT_STAT_OVERCURRENT) || (portchange & USB_PORT_STAT_C_OVERCURRENT)) set_bit(port1, hub->change_bits);