From patchwork Fri Apr 7 02:46:15 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Badhri Jagan Sridharan X-Patchwork-Id: 13204428 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 4C68DC76196 for ; Fri, 7 Apr 2023 02:46:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239255AbjDGCqW (ORCPT ); Thu, 6 Apr 2023 22:46:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41484 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232388AbjDGCqV (ORCPT ); Thu, 6 Apr 2023 22:46:21 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1CB58171C for ; Thu, 6 Apr 2023 19:46:20 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id f66-20020a255145000000b00b714602d43fso41439769ybb.10 for ; Thu, 06 Apr 2023 19:46:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1680835579; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=X9Rz+HRx+XbHQ92YClzq3vIFnfPscmBVuxfoPYpEX+8=; b=AoiOixwVjrY7Ov4MEH5msU1Xa1WRXhCgWDkttHOw6jq2R4VK2eJImQypcUEOrFabrm ZSB5VqNBuc6qT8GKRd18ktpTecaYxlSPYwAlIgTzubwXyflFj2CL5Mi4temRjyTojFZN 5X04jDOL8jFvCf+3pSmLYEdCYgsLdemqZN+jjyZAFPpUWcV/o585vKGWly9A5U6rFSFz r9X0JujfPm0oIaT9blO7YtFRzpPS7M6T+sRwxNPbNGLa6nK7bqnky7otHSDb+Axcp0sD M7EaFxtfTeLmOPDnECMReO3fuoPXnpB3AQDIgubChWJfZ6q79PnVxCafheYr7AgtS/4k MYOA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680835579; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=X9Rz+HRx+XbHQ92YClzq3vIFnfPscmBVuxfoPYpEX+8=; b=RQCRDn6jGk2P9vpxwOYWal4oNHCFNFO1+HdkNGvLmrHnDrHFRtOVSpJSOoLSho9+Id J8GkM5htIRpxwENu8+G55dwoyML8EQO6Iid9fjp71VEXg/LY8kUAIGA21xcbSsvhqFeO QCD1UIwjxYlkJq6WynUGu0rKS35apv07bZffjz8GiyDbkgnxLEV1+KvyfZ/gYL0jzXxg s8v7d/EgDhwMeiYlmpTlhUOfBWwG/coZmYcS9HzR2nWhrZnFy/h/ACMcF0uruyMOk/mS /oiLnKAB6Rx3xhzZlDFt62OYh25iPI6zyDxnXs8F2OC18a14wHZx9dlybUS/1ebJp3Kr 02Cw== X-Gm-Message-State: AAQBX9datiNlDnIW8KxUVBKwA1GQ1Ms7rFN4nPtHR0r5JuHTA2djbZFE W5R1S8DrdN0v7o2rKKZJ7hoVrtBpwWY= X-Google-Smtp-Source: AKy350ZgmNHnxaxrXoUBca4rNjZ7xVisK3yiJ57WS4j0YCFVThdVBgsHaafjejDTwekSehzOaQZYM565zZ8= X-Received: from badhri.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:6442]) (user=badhri job=sendgmr) by 2002:a25:c483:0:b0:b4c:9333:2a1 with SMTP id u125-20020a25c483000000b00b4c933302a1mr978149ybf.10.1680835579337; Thu, 06 Apr 2023 19:46:19 -0700 (PDT) Date: Fri, 7 Apr 2023 02:46:15 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.40.0.577.gac1e443424-goog Message-ID: <20230407024616.2883701-1-badhri@google.com> Subject: [PATCH v3 1/2] usb: gadget: udc: core: Invoke usb_gadget_connect only when started From: Badhri Jagan Sridharan To: gregkh@linuxfoundation.org, stern@rowland.harvard.edu, colin.i.king@gmail.com, xuetao09@huawei.com, quic_eserrao@quicinc.com, water.zhangjiantao@huawei.com, peter.chen@freescale.com, balbi@ti.com Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Badhri Jagan Sridharan Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org usb_udc_connect_control does not check to see if the udc has already been started. This causes gadget->ops->pullup to be called through usb_gadget_connect when invoked from usb_udc_vbus_handler even before usb_gadget_udc_start is called. Guard this by checking for udc->started in usb_udc_connect_control before invoking usb_gadget_connect. Guarding udc->vbus, udc->started, gadget->connect, gadget->deactivate related functions with connect_lock. usb_gadget_connect_locked, usb_gadget_disconnect_locked, usb_udc_connect_control_locked, usb_gadget_udc_start_locked, usb_gadget_udc_stop_locked are called with this lock held as they can be simulataneously invoked from different code paths. Adding an additional check to make sure udc is started(udc->started) before pullup callback is invoked. Cc: stable@vger.kernel.org Fixes: 628ef0d273a6 ("usb: udc: add usb_udc_vbus_handler") Signed-off-by: Badhri Jagan Sridharan --- Changes since v2: * Added __must_hold marking for connect_lock Changes since v1: * Fixed commit message comments. * Renamed udc_connect_control_lock to connect_lock and made it per device. * udc->vbus, udc->started, gadget->connect, gadget->deactivate are all now guarded by connect_lock. * Code now checks for udc->started to be set before invoking pullup callback. --- drivers/usb/gadget/udc/core.c | 146 ++++++++++++++++++++++++---------- 1 file changed, 102 insertions(+), 44 deletions(-) base-commit: d629c0e221cd99198b843d8351a0a9bfec6c0423 diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index 3dcbba739db6..3eb5d4e392db 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -37,6 +37,10 @@ static struct bus_type gadget_bus_type; * @vbus: for udcs who care about vbus status, this value is real vbus status; * for udcs who do not care about vbus status, this value is always true * @started: the UDC's started state. True if the UDC had started. + * @connect_lock: protects udc->vbus, udc->started, gadget->connect, gadget->deactivate related + * functions. usb_gadget_connect_locked, usb_gadget_disconnect_locked, + * usb_udc_connect_control_locked, usb_gadget_udc_start_locked, usb_gadget_udc_stop_locked are + * called with this lock held. * * This represents the internal data structure which is used by the UDC-class * to hold information about udc driver and gadget together. @@ -48,6 +52,7 @@ struct usb_udc { struct list_head list; bool vbus; bool started; + struct mutex connect_lock; }; static struct class *udc_class; @@ -687,17 +692,8 @@ int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) } EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect); -/** - * usb_gadget_connect - software-controlled connect to USB host - * @gadget:the peripheral being connected - * - * Enables the D+ (or potentially D-) pullup. The host will start - * enumerating this gadget when the pullup is active and a VBUS session - * is active (the link is powered). - * - * Returns zero on success, else negative errno. - */ -int usb_gadget_connect(struct usb_gadget *gadget) +/* Internal version of usb_gadget_connect needs to be called with connect_lock held. */ +int usb_gadget_connect_locked(struct usb_gadget *gadget) __must_hold(&gadget->udc->connect_lock) { int ret = 0; @@ -706,10 +702,12 @@ int usb_gadget_connect(struct usb_gadget *gadget) goto out; } - if (gadget->deactivated) { + if (gadget->deactivated || !gadget->udc->started) { /* * If gadget is deactivated we only save new state. * Gadget will be connected automatically after activation. + * + * udc first needs to be started before gadget can be pulled up. */ gadget->connected = true; goto out; @@ -724,22 +722,31 @@ int usb_gadget_connect(struct usb_gadget *gadget) return ret; } -EXPORT_SYMBOL_GPL(usb_gadget_connect); /** - * usb_gadget_disconnect - software-controlled disconnect from USB host - * @gadget:the peripheral being disconnected - * - * Disables the D+ (or potentially D-) pullup, which the host may see - * as a disconnect (when a VBUS session is active). Not all systems - * support software pullup controls. + * usb_gadget_connect - software-controlled connect to USB host + * @gadget:the peripheral being connected * - * Following a successful disconnect, invoke the ->disconnect() callback - * for the current gadget driver so that UDC drivers don't need to. + * Enables the D+ (or potentially D-) pullup. The host will start + * enumerating this gadget when the pullup is active and a VBUS session + * is active (the link is powered). * * Returns zero on success, else negative errno. */ -int usb_gadget_disconnect(struct usb_gadget *gadget) +int usb_gadget_connect(struct usb_gadget *gadget) +{ + int ret; + + mutex_lock(&gadget->udc->connect_lock); + ret = usb_gadget_connect_locked(gadget); + mutex_unlock(&gadget->udc->connect_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(usb_gadget_connect); + +/* Internal version of usb_gadget_disconnect needs to be called with connect_lock held. */ +int usb_gadget_disconnect_locked(struct usb_gadget *gadget) __must_hold(&gadget->udc->connect_lock) { int ret = 0; @@ -751,10 +758,12 @@ int usb_gadget_disconnect(struct usb_gadget *gadget) if (!gadget->connected) goto out; - if (gadget->deactivated) { + if (gadget->deactivated || !gadget->udc->started) { /* * If gadget is deactivated we only save new state. * Gadget will stay disconnected after activation. + * + * udc should have been started before gadget being pulled down. */ gadget->connected = false; goto out; @@ -774,6 +783,30 @@ int usb_gadget_disconnect(struct usb_gadget *gadget) return ret; } + +/** + * usb_gadget_disconnect - software-controlled disconnect from USB host + * @gadget:the peripheral being disconnected + * + * Disables the D+ (or potentially D-) pullup, which the host may see + * as a disconnect (when a VBUS session is active). Not all systems + * support software pullup controls. + * + * Following a successful disconnect, invoke the ->disconnect() callback + * for the current gadget driver so that UDC drivers don't need to. + * + * Returns zero on success, else negative errno. + */ +int usb_gadget_disconnect(struct usb_gadget *gadget) +{ + int ret; + + mutex_lock(&gadget->udc->connect_lock); + ret = usb_gadget_disconnect_locked(gadget); + mutex_unlock(&gadget->udc->connect_lock); + + return ret; +} EXPORT_SYMBOL_GPL(usb_gadget_disconnect); /** @@ -794,10 +827,11 @@ int usb_gadget_deactivate(struct usb_gadget *gadget) if (gadget->deactivated) goto out; + mutex_lock(&gadget->udc->connect_lock); if (gadget->connected) { - ret = usb_gadget_disconnect(gadget); + ret = usb_gadget_disconnect_locked(gadget); if (ret) - goto out; + goto unlock; /* * If gadget was being connected before deactivation, we want @@ -807,6 +841,8 @@ int usb_gadget_deactivate(struct usb_gadget *gadget) } gadget->deactivated = true; +unlock: + mutex_unlock(&gadget->udc->connect_lock); out: trace_usb_gadget_deactivate(gadget, ret); @@ -830,6 +866,7 @@ int usb_gadget_activate(struct usb_gadget *gadget) if (!gadget->deactivated) goto out; + mutex_lock(&gadget->udc->connect_lock); gadget->deactivated = false; /* @@ -837,7 +874,8 @@ int usb_gadget_activate(struct usb_gadget *gadget) * while it was being deactivated, we call usb_gadget_connect(). */ if (gadget->connected) - ret = usb_gadget_connect(gadget); + ret = usb_gadget_connect_locked(gadget); + mutex_unlock(&gadget->udc->connect_lock); out: trace_usb_gadget_activate(gadget, ret); @@ -1078,12 +1116,13 @@ EXPORT_SYMBOL_GPL(usb_gadget_set_state); /* ------------------------------------------------------------------------- */ -static void usb_udc_connect_control(struct usb_udc *udc) +/* Acquire connect_lock before calling this function. */ +static void usb_udc_connect_control_locked(struct usb_udc *udc) __must_hold(&udc->connect_lock) { - if (udc->vbus) - usb_gadget_connect(udc->gadget); + if (udc->vbus && udc->started) + usb_gadget_connect_locked(udc->gadget); else - usb_gadget_disconnect(udc->gadget); + usb_gadget_disconnect_locked(udc->gadget); } /** @@ -1099,10 +1138,12 @@ void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status) { struct usb_udc *udc = gadget->udc; + mutex_lock(&udc->connect_lock); if (udc) { udc->vbus = status; - usb_udc_connect_control(udc); + usb_udc_connect_control_locked(udc); } + mutex_unlock(&udc->connect_lock); } EXPORT_SYMBOL_GPL(usb_udc_vbus_handler); @@ -1124,7 +1165,7 @@ void usb_gadget_udc_reset(struct usb_gadget *gadget, EXPORT_SYMBOL_GPL(usb_gadget_udc_reset); /** - * usb_gadget_udc_start - tells usb device controller to start up + * usb_gadget_udc_start_locked - tells usb device controller to start up * @udc: The UDC to be started * * This call is issued by the UDC Class driver when it's about @@ -1135,8 +1176,11 @@ EXPORT_SYMBOL_GPL(usb_gadget_udc_reset); * necessary to have it powered on. * * Returns zero on success, else negative errno. + * + * Caller should acquire connect_lock before invoking this function. */ -static inline int usb_gadget_udc_start(struct usb_udc *udc) +static inline int usb_gadget_udc_start_locked(struct usb_udc *udc) + __must_hold(&udc->connect_lock) { int ret; @@ -1153,7 +1197,7 @@ static inline int usb_gadget_udc_start(struct usb_udc *udc) } /** - * usb_gadget_udc_stop - tells usb device controller we don't need it anymore + * usb_gadget_udc_stop_locked - tells usb device controller we don't need it anymore * @udc: The UDC to be stopped * * This call is issued by the UDC Class driver after calling @@ -1162,8 +1206,11 @@ static inline int usb_gadget_udc_start(struct usb_udc *udc) * The details are implementation specific, but it can go as * far as powering off UDC completely and disable its data * line pullups. + * + * Caller should acquire connect lock before invoking this function. */ -static inline void usb_gadget_udc_stop(struct usb_udc *udc) +static inline void usb_gadget_udc_stop_locked(struct usb_udc *udc) + __must_hold(&udc->connect_lock) { if (!udc->started) { dev_err(&udc->dev, "UDC had already stopped\n"); @@ -1322,6 +1369,7 @@ int usb_add_gadget(struct usb_gadget *gadget) udc->gadget = gadget; gadget->udc = udc; + mutex_init(&udc->connect_lock); udc->started = false; @@ -1523,11 +1571,15 @@ static int gadget_bind_driver(struct device *dev) if (ret) goto err_bind; - ret = usb_gadget_udc_start(udc); - if (ret) + mutex_lock(&udc->connect_lock); + ret = usb_gadget_udc_start_locked(udc); + if (ret) { + mutex_unlock(&udc->connect_lock); goto err_start; + } usb_gadget_enable_async_callbacks(udc); - usb_udc_connect_control(udc); + usb_udc_connect_control_locked(udc); + mutex_unlock(&udc->connect_lock); kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE); return 0; @@ -1558,12 +1610,14 @@ static void gadget_unbind_driver(struct device *dev) kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE); - usb_gadget_disconnect(gadget); + mutex_lock(&udc->connect_lock); + usb_gadget_disconnect_locked(gadget); usb_gadget_disable_async_callbacks(udc); if (gadget->irq) synchronize_irq(gadget->irq); udc->driver->unbind(gadget); - usb_gadget_udc_stop(udc); + usb_gadget_udc_stop_locked(udc); + mutex_unlock(&udc->connect_lock); mutex_lock(&udc_lock); driver->is_bound = false; @@ -1649,11 +1703,15 @@ static ssize_t soft_connect_store(struct device *dev, } if (sysfs_streq(buf, "connect")) { - usb_gadget_udc_start(udc); - usb_gadget_connect(udc->gadget); + mutex_lock(&udc->connect_lock); + usb_gadget_udc_start_locked(udc); + usb_gadget_connect_locked(udc->gadget); + mutex_unlock(&udc->connect_lock); } else if (sysfs_streq(buf, "disconnect")) { - usb_gadget_disconnect(udc->gadget); - usb_gadget_udc_stop(udc); + mutex_lock(&udc->connect_lock); + usb_gadget_disconnect_locked(udc->gadget); + usb_gadget_udc_stop_locked(udc); + mutex_unlock(&udc->connect_lock); } else { dev_err(dev, "unsupported command '%s'\n", buf); ret = -EINVAL;