From patchwork Thu Sep 8 10:40:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ray Chi X-Patchwork-Id: 12969898 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31CE6ECAAD5 for ; Thu, 8 Sep 2022 10:41:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230430AbiIHKlA (ORCPT ); Thu, 8 Sep 2022 06:41:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42028 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231284AbiIHKkc (ORCPT ); Thu, 8 Sep 2022 06:40:32 -0400 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 574689C1C2 for ; Thu, 8 Sep 2022 03:40:25 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-345158b6641so107430097b3.8 for ; Thu, 08 Sep 2022 03:40:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date; bh=4Isgkuea9p0Arz+WvNNRlBz5xkeTJ+kAkTQabzxUrw0=; b=syzJXntYI5F+CwDlx8P2LUzhxgadSnNa7z31ZO+PPe4KTJUbPA7jSXOHdCT1HbdrYV xeE9T9iDT5T47+CLHVUbAzAZ5VRxQC9/eKRTkbp+FMQrH4e4QmA3C2Cf76aJ+r5f/gIO azMkEEEjYixjmFxh6WWfpaqkS/PbSM82vvQzwau70OTnI6AMIudsQGt6/hDJzaoPfMiz HhkxE+jYoLu5aIxq290M+b+mCCUnEQx8VvVV+wyRY7fCWGZyKxEdwd64ngrS7RfRTQms jHbjep4s3GNy1fyibYlJsdUbL5uaVmTosOYgOVLARyl3rwbkhlO15oZPabETUNDDwtUn U48Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date; bh=4Isgkuea9p0Arz+WvNNRlBz5xkeTJ+kAkTQabzxUrw0=; b=Qc6SaI6RIKPRcC9ETB3Pzbw0o1ipJTkOC49pBFSX8DSTbVx3YHecuFUy0mJ4P689+J diYJJRSXSjbyjCqHxAc6NNcdcKZUS/o5Lqm/mhDGhbeQdZVr/ZSs2VXl5eFiakE7wvK6 A7kSPRRx+QcAhPZXGDq/DsSFIIU1id8vQNv/0axF6Lv/ZT2VMKIkdJ8ceLUoi94YZ75z g9AJu5CbCFwrdMG7Stxo15wOEQt6fDOvTHp2ZJJmG935P0U9d++U47ee97hzkGvYPxIj HeSzGWZZ/8efKYZzEXNdyKK5Daz+qEqXEtPay0bTY/JRUl9DfRzzoQy/hB9UWM6ePy25 B4bw== X-Gm-Message-State: ACgBeo1iLQIuBuJNzp29PW5jYUJKdeq4cVIPIvBiv0d4q3tVkPbrPPsl PvEUQINkolceb/G/rNPGFFDz96fdxvc= X-Google-Smtp-Source: AA6agR5xCKRj7XtJs+eibi6g49PcdjCpjupmCgC8d8UbBXpu8Z2cRkrM7vlM5R52PLtZFubhNYHII2TcN14= X-Received: from raychi.tao.corp.google.com ([2401:fa00:fc:202:20dd:9a84:5a59:3c44]) (user=raychi job=sendgmr) by 2002:a25:9803:0:b0:696:489e:b84d with SMTP id a3-20020a259803000000b00696489eb84dmr6590489ybo.317.1662633624609; Thu, 08 Sep 2022 03:40:24 -0700 (PDT) Date: Thu, 8 Sep 2022 18:40:19 +0800 Mime-Version: 1.0 X-Mailer: git-send-email 2.37.2.789.g6183377224-goog Message-ID: <20220908104019.3080989-1-raychi@google.com> Subject: [Patch v3] usb: core: stop USB enumeration if too many retries From: Ray Chi To: gregkh@linuxfoundation.org, stern@rowland.harvard.edu, mchehab+huawei@kernel.org Cc: albertccwang@google.com, badhri@google.com, pumahsu@google.com, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, Ray Chi Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org When a broken USB accessory connects to a USB host, usbcore might keep doing enumeration retries. If the host has a watchdog mechanism, the kernel panic will happen on the host. The patch provide a attribute to limit the numbers of retries and timeout lengths. In addition, it also adds a function to stop the port initialization and ignore events on the port if the broken accessory is still connected. Signed-off-by: Ray Chi --- Changes since v2: - replace the quirk with the attribute - Document the attribute - modify hub_port_stop_enumerate() position in port_event() - modify the changelog Changes since v1: - remove usb_hub_set_port_power() - add a variable ignore_connect into struct port_dev - modify hub_port_stop_enumerate() and set ignore_connect in this function - avoid calling hub_port_connect_change() in port_event() --- Documentation/ABI/testing/sysfs-bus-usb | 9 ++++++ drivers/usb/core/hub.c | 39 +++++++++++++++++++++++++ drivers/usb/core/hub.h | 4 +++ drivers/usb/core/port.c | 23 +++++++++++++++ 4 files changed, 75 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb index 568103d3376e..d44c8aaef929 100644 --- a/Documentation/ABI/testing/sysfs-bus-usb +++ b/Documentation/ABI/testing/sysfs-bus-usb @@ -264,6 +264,15 @@ Description: attached to the port will not be detected, initialized, or enumerated. +What: /sys/bus/usb/devices/...//port/quick_init +Date: Sep 2022 +Contact: Ray Chi +Description: + Some USB hosts have some watchdog mechanisms so that the device + may enter ramdump if it takes a long time during port initialization. + This attribute limits the numbers of retries and timeout lengths once + an initialization of the port meets failures. + What: /sys/bus/usb/devices/.../power/usb2_lpm_l1_timeout Date: May 2013 Contact: Mathias Nyman diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index d4b1e70d1498..f22caa133274 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -3081,6 +3081,29 @@ static int hub_port_reset(struct usb_hub *hub, int port1, return status; } +/* Check whether a hub would stop enumeration or ignore events on the port. */ +static bool hub_port_stop_enumerate(struct usb_hub *hub, int port1, int retries) +{ + struct usb_port *port_dev = hub->ports[port1 - 1]; + + if (port_dev->quick_init) { + if (port_dev->ignore_connect) + return true; + + /* + * Since some normal devices will be timeout in the first attempt, + * set the condition to half of the retries + */ + if (retries < (PORT_INIT_TRIES - 1) / 2) + return false; + + port_dev->ignore_connect = true; + } else + port_dev->ignore_connect = false; + + return port_dev->ignore_connect; +} + /* Check if a port is power on */ int usb_port_is_power_on(struct usb_hub *hub, unsigned int portstatus) { @@ -4855,6 +4878,11 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1, buf->bMaxPacketSize0; kfree(buf); + if (r < 0 && port_dev->quick_init) { + retval = r; + goto fail; + } + retval = hub_port_reset(hub, port1, udev, delay, false); if (retval < 0) /* error or disconnect */ goto fail; @@ -5387,6 +5415,9 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, if ((status == -ENOTCONN) || (status == -ENOTSUPP)) break; + if (hub_port_stop_enumerate(hub, port1, i)) + break; + /* When halfway through our retry count, power-cycle the port */ if (i == (PORT_INIT_TRIES - 1) / 2) { dev_info(&port_dev->dev, "attempt power cycle\n"); @@ -5614,6 +5645,9 @@ static void port_event(struct usb_hub *hub, int port1) if (!pm_runtime_active(&port_dev->dev)) return; + if (hub_port_stop_enumerate(hub, port1, 0)) + return; + if (hub_handle_remote_wakeup(hub, port1, portstatus, portchange)) connect_change = 1; @@ -5934,6 +5968,9 @@ static int usb_reset_and_verify_device(struct usb_device *udev) ret = hub_port_init(parent_hub, udev, port1, i); if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV) break; + + if (hub_port_stop_enumerate(parent_hub, port1, i)) + goto stop_enumerate; } mutex_unlock(hcd->address0_mutex); @@ -6022,6 +6059,8 @@ static int usb_reset_and_verify_device(struct usb_device *udev) udev->bos = bos; return 0; +stop_enumerate: + mutex_unlock(hcd->address0_mutex); re_enumerate: usb_release_bos_descriptor(udev); udev->bos = bos; diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h index b2925856b4cb..57995ec3af58 100644 --- a/drivers/usb/core/hub.h +++ b/drivers/usb/core/hub.h @@ -90,6 +90,8 @@ struct usb_hub { * @is_superspeed cache super-speed status * @usb3_lpm_u1_permit: whether USB3 U1 LPM is permitted. * @usb3_lpm_u2_permit: whether USB3 U2 LPM is permitted. + * @ignore_connect: ignore the connection or not. + * @quick_init: limit the numbers of retries for port initialization */ struct usb_port { struct usb_device *child; @@ -103,6 +105,8 @@ struct usb_port { u32 over_current_count; u8 portnum; u32 quirks; + bool ignore_connect; + bool quick_init; unsigned int is_superspeed:1; unsigned int usb3_lpm_u1_permit:1; unsigned int usb3_lpm_u2_permit:1; diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c index 38c1a4f4fdea..7d5acd3ff353 100644 --- a/drivers/usb/core/port.c +++ b/drivers/usb/core/port.c @@ -17,6 +17,28 @@ static int usb_port_block_power_off; static const struct attribute_group *port_dev_group[]; +static ssize_t quick_init_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct usb_port *port_dev = to_usb_port(dev); + + return sysfs_emit(buf, "%s\n", port_dev->quick_init ? "yes" : "no"); +} + +static ssize_t quick_init_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct usb_port *port_dev = to_usb_port(dev); + bool value; + + if (kstrtobool(buf, &value)) + return -EINVAL; + + port_dev->quick_init = value; + return count; +} +static DEVICE_ATTR_RW(quick_init); + static ssize_t disable_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -236,6 +258,7 @@ static struct attribute *port_dev_attrs[] = { &dev_attr_quirks.attr, &dev_attr_over_current_count.attr, &dev_attr_disable.attr, + &dev_attr_quick_init.attr, NULL, };