From patchwork Fri May 1 13:21:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 226665 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, URIBL_BLOCKED, 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 21B0CC4724C for ; Fri, 1 May 2020 13:32:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 00F33208C3 for ; Fri, 1 May 2020 13:32:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588339978; bh=LmpQIxXgd4sQZVcscMsOXJbFpiz8wPrmMdzRd9rSilo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=x4yHAZ0Ng7CRhjnOd4ZwMXX09DwKbrPDQJMlr5mbB++tnWGuclb5zUAJtT3Ve7dXE KyyNyvvCAu6ajYCVjgb3VRU8y+NMHCkNLi7XSmmTEiImuscmzm7rQ7xDPnD/v1poF8 12XvIkGgyeUQT7NCTQc9+hjkTO0dKyE/0irXE/RI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729772AbgEANc4 (ORCPT ); Fri, 1 May 2020 09:32:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:58124 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729798AbgEANcz (ORCPT ); Fri, 1 May 2020 09:32:55 -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 7068D208C3; Fri, 1 May 2020 13:32:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588339974; bh=LmpQIxXgd4sQZVcscMsOXJbFpiz8wPrmMdzRd9rSilo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YoOLAE8vF861FbZYqKgDE2ksN+vbIqT0Go5hX2PPx63FVAEpNJTUZYjjzXS9bww7Q u0wDPDCjLEDLKMyTZ6eSx4tnbjHOho4FPKrXEELxnzYyMfG07PA79lImYkGZ+1i9qm ji0Kj9+4J9q9twwihx5HBfatMY4gRiBu6VJxOsvQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alan Stern , Paul Zimmerman , Peter Chen Subject: [PATCH 4.14 047/117] USB: hub: Fix handling of connect changes during sleep Date: Fri, 1 May 2020 15:21:23 +0200 Message-Id: <20200501131550.361609021@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200501131544.291247695@linuxfoundation.org> References: <20200501131544.291247695@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alan Stern commit 9f952e26295d977dbfc6fedeaf8c4f112c818d37 upstream. 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(+) --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -1195,6 +1195,11 @@ static void hub_activate(struct usb_hub #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 */ @@ -3008,6 +3013,15 @@ static int check_port_resume_type(struct 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;