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=-11.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 884AEC54FCB for ; Thu, 23 Apr 2020 13:23:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 447D420781 for ; Thu, 23 Apr 2020 13:23:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587648215; bh=8RdMfHDr3CjNsAQ4XtPG07sXr/qyMQu1lN4QqXiQ9/Y=; h=Subject:To:From:Date:List-ID:From; b=PBoT1CJlrE4YgUwlHlPcuVS6MtqkMJbt8GKB7HAgycNS31kSeqSJ28bokELab0OlI S/MjR5FpZeC98Bv6sfFsD6IgMaAQ9SiEt76ritwmE7exYzUTWr2krf0tNjknQ0L9za cX0zW0P9CxIOjwg28riB6/foy2PNsAtuxugnjT/4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726926AbgDWNXe (ORCPT ); Thu, 23 Apr 2020 09:23:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:53088 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726224AbgDWNXe (ORCPT ); Thu, 23 Apr 2020 09:23:34 -0400 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 B0DEE20704; Thu, 23 Apr 2020 13:23:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587648214; bh=8RdMfHDr3CjNsAQ4XtPG07sXr/qyMQu1lN4QqXiQ9/Y=; h=Subject:To:From:Date:From; b=erjjwJhUpfr0nbCdzSkYzz91dZRagQWqcykbp2HFH8ZpCpzBU4tsJVS2eDW3MUDob 5FKmZweKQJu7bomj99y4bDTQxpqkWoDr/RTw6vUfytGmygc+ZNpTjyB/KSjQbszQxN 1YGvJ6SFmH0AFe4HoB4WgQajMts/lSM51PbO37cQ= Subject: patch "USB: hub: Fix handling of connect changes during sleep" added to usb-linus To: stern@rowland.harvard.edu, gregkh@linuxfoundation.org, pauldzim@gmail.com, peter.chen@nxp.com, stable@vger.kernel.org From: Date: Thu, 23 Apr 2020 15:23:31 +0200 Message-ID: <158764821114578@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This is a note to let you know that I've just added the patch titled USB: hub: Fix handling of connect changes during sleep to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >From 9f952e26295d977dbfc6fedeaf8c4f112c818d37 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 22 Apr 2020 16:09:51 -0400 Subject: USB: hub: Fix handling of connect changes during sleep Commit 8099f58f1ecd ("USB: hub: Don't record a connect-change event during reset-resume") wasn't very well conceived. The problem it tried to fix was that if a connect-change event occurred while the system was asleep (such as a device disconnecting itself from the bus when it is suspended and then reconnecting when it resumes) requiring a reset-resume during the system wakeup transition, the hub port's change_bit entry would remain set afterward. This would cause the hub driver to believe another connect-change event had occurred after the reset-resume, which was wrong and would lead the driver to send unnecessary requests to the device (which could interfere with a firmware update). The commit tried to fix this by not setting the change_bit during the wakeup. But this was the wrong thing to do; it means that when a device is unplugged while the system is asleep, the hub driver doesn't realize anything has happened: The change_bit flag which would tell it to handle the disconnect event is clear. The commit needs to be reverted and the problem fixed in a different way. Fortunately an alternative solution was noted in the commit's Changelog: We can continue to set the change_bit entry in hub_activate() but then clear it when a reset-resume occurs. That way the the hub driver will see the change_bit when a device is disconnected but won't see it when the device is still present. That's what this patch does. Reported-and-tested-by: Peter Chen Signed-off-by: Alan Stern Fixes: 8099f58f1ecd ("USB: hub: Don't record a connect-change event during reset-resume") Tested-by: Paul Zimmerman CC: Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.2004221602480.11262-100000@iolanthe.rowland.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hub.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 54cd8ef795ec..83549f009ced 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -1223,6 +1223,11 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type) #ifdef CONFIG_PM udev->reset_resume = 1; #endif + /* Don't set the change_bits when the device + * was powered off. + */ + if (test_bit(port1, hub->power_bits)) + set_bit(port1, hub->change_bits); } else { /* The power session is gone; tell hub_wq */ @@ -3088,6 +3093,15 @@ static int check_port_resume_type(struct usb_device *udev, if (portchange & USB_PORT_STAT_C_ENABLE) usb_clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_ENABLE); + + /* + * Whatever made this reset-resume necessary may have + * turned on the port1 bit in hub->change_bits. But after + * a successful reset-resume we want the bit to be clear; + * if it was on it would indicate that something happened + * following the reset-resume. + */ + clear_bit(port1, hub->change_bits); } return status; -- 2.26.2