From patchwork Wed May 31 04:02:01 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: 687664 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 F07D9C77B73 for ; Wed, 31 May 2023 04:02:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234030AbjEaECL (ORCPT ); Wed, 31 May 2023 00:02:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232344AbjEaECJ (ORCPT ); Wed, 31 May 2023 00:02:09 -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 04A6BFC for ; Tue, 30 May 2023 21:02:08 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id 3f1490d57ef6-ba81b37d9d2so9689858276.3 for ; Tue, 30 May 2023 21:02:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1685505727; x=1688097727; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=FRShDzU+m20ot9o4O+80g75qyx0AzeQfhVYqf4ZY7r8=; b=Ql0coGq15Pj7nTlxZq2f/RivqyjWmPolPYZ2HZFcuekbbm33jfO2dDe82WO2v1/qbk /0rAWbwAhOEAeLqo+DBjfOUetbwAHYSr6SCT7UNmRnoKrZhODAzGy6rozWxzB0GFfoeK LDoujjTAbvrWNyIgH5c/Pg613GMixADgkWZf5GXNLKoofc9DJ5AkH5wzAL4ppeN/yd+t jXSLlKA9RdamVar9TI4EUuLsUSNbXVZbkRRlZQXHZ5/1cF7c2TQfTlUVFQWn+Knn4T5T b93NBITM+3BHDI02S2hws83FjuuCzNBdhptgbJvPXHSzwhPWaFmO42Jl5l5KXThnr0Xz FRaA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685505727; x=1688097727; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=FRShDzU+m20ot9o4O+80g75qyx0AzeQfhVYqf4ZY7r8=; b=RZ0Uod//ZDyS7wcl90kzqrbMbR28E9WUXm2oBoh2zwvYwG766DaCWFjZVMs+b3nmgo l9vnsEtugeWC+8XMKVHMZJr0ail+k4nhndRJKF8yVsniR2p+H72cOi7lnzfjsbCdET7d I08PzU9FBQgaV9ygnIKM1GtnZxE6aHc72zJprGdVS6B24mymPpoXbRVZaMQO2AlYHol0 kaf7wrWM12BKtj2JTZH90ErsyOYzwUBTaTcUfGrm0xg814FIJ4RIPOAhMxwRY+jRwp86 tIFii2mcDufTA5TGko6zN56hNZKTFGAbBIHe08WgCNgRykeAmKofBJRB0oOYRNwAy4Gb jQoA== X-Gm-Message-State: AC+VfDwQaMcCvGTwa11AL744nj13nQ9J0C6YdVJb6BOzzO2Yoi9y+dOp mKosmIAMIdAUwPkSVdqb5+tXWmuxgCk= X-Google-Smtp-Source: ACHHUZ4ub/AbluMPbZht6ZvhJeeDHG3ymN5X09VDEgsrBNofrc3dYiieroVxZdqj+lnI/TXtJaCBv3cEWgk= X-Received: from badhri.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:6442]) (user=badhri job=sendgmr) by 2002:a5b:14f:0:b0:bac:faf4:78fd with SMTP id c15-20020a5b014f000000b00bacfaf478fdmr1794911ybp.7.1685505727275; Tue, 30 May 2023 21:02:07 -0700 (PDT) Date: Wed, 31 May 2023 04:02:01 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.41.0.rc0.172.g3f132b7071-goog Message-ID: <20230531040203.19295-1-badhri@google.com> Subject: [PATCH v5 1/3] usb: gadget: udc: core: Offload usb_udc_vbus_handler processing 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, francesco@dolcini.it, alistair@alistair23.me, stephan@gerhold.net, bagasdotme@gmail.com, luca@z3ntu.xyz 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_vbus_handler() can be invoked from interrupt context by irq handlers of the gadget drivers, however, usb_udc_connect_control() has to run in non-atomic context due to the following: a. Some of the gadget driver implementations expect the ->pullup callback to be invoked in non-atomic context. b. usb_gadget_disconnect() acquires udc_lock which is a mutex. Hence offload invocation of usb_udc_connect_control() to workqueue. Cc: stable@vger.kernel.org Fixes: 1016fc0c096c ("USB: gadget: Fix obscure lockdep violation for udc_mutex") Signed-off-by: Badhri Jagan Sridharan --- Changes since v1: - Address Alan Stern's comment on usb_udc_vbus_handler invocation from atomic context: * vbus_events_lock is now a spinlock and allocations in * usb_udc_vbus_handler are atomic now. Changes since v2: - Addressing Alan Stern's comments: ** connect_lock is now held by callers of * usb_gadget_pullup_update_locked() and gadget_(un)bind_driver() does * notdirectly hold the lock. ** Both usb_gadget_(dis)connect() and usb_udc_vbus_handler() would * set/clear udc->vbus and invoke usb_gadget_pullup_update_locked. ** Add "unbinding" to prevent new connections after the gadget is being * unbound. Changes since v3: ** Made a minor cleanup which I missed to do in v3 in * usb_udc_vbus_handler(). Changes since v4: - Addressing Alan Stern's comments: ** usb_udc_vbus_handler() now offloads invocation of usb_udc_connect_control() * from workqueue. ** Dropped vbus_events list as this was redundant. Updating to the * latest value is suffice --- drivers/usb/gadget/udc/core.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) base-commit: 046895105d9666ab56e86ce8dd9786f8003125c6 diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index 52e6d2e84e35..44a9f32679b5 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -48,6 +48,7 @@ struct usb_udc { struct list_head list; bool vbus; bool started; + struct work_struct vbus_work; }; static struct class *udc_class; @@ -1086,6 +1087,13 @@ static void usb_udc_connect_control(struct usb_udc *udc) usb_gadget_disconnect(udc->gadget); } +static void vbus_event_work(struct work_struct *work) +{ + struct usb_udc *udc = container_of(work, struct usb_udc, vbus_work); + + usb_udc_connect_control(udc); +} + /** * usb_udc_vbus_handler - updates the udc core vbus status, and try to * connect or disconnect gadget @@ -1094,6 +1102,13 @@ static void usb_udc_connect_control(struct usb_udc *udc) * * The udc driver calls it when it wants to connect or disconnect gadget * according to vbus status. + * + * This function can be invoked from interrupt context by irq handlers of the gadget drivers, + * however, usb_udc_connect_control() has to run in non-atomic context due to the following: + * a. Some of the gadget driver implementations expect the ->pullup callback to be invoked in + * non-atomic context. + * b. usb_gadget_disconnect() acquires udc_lock which is a mutex. + * Hence offload invocation of usb_udc_connect_control() to workqueue. */ void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status) { @@ -1101,7 +1116,7 @@ void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status) if (udc) { udc->vbus = status; - usb_udc_connect_control(udc); + schedule_work(&udc->vbus_work); } } EXPORT_SYMBOL_GPL(usb_udc_vbus_handler); @@ -1328,6 +1343,7 @@ int usb_add_gadget(struct usb_gadget *gadget) mutex_lock(&udc_lock); list_add_tail(&udc->list, &udc_list); mutex_unlock(&udc_lock); + INIT_WORK(&udc->vbus_work, vbus_event_work); ret = device_add(&udc->dev); if (ret) @@ -1558,6 +1574,7 @@ static void gadget_unbind_driver(struct device *dev) kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE); + cancel_work_sync(&udc->vbus_work); usb_gadget_disconnect(gadget); usb_gadget_disable_async_callbacks(udc); if (gadget->irq) From patchwork Wed May 31 04:02:02 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: 688185 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 31C9DC77B7A for ; Wed, 31 May 2023 04:02:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234167AbjEaECT (ORCPT ); Wed, 31 May 2023 00:02:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234050AbjEaECN (ORCPT ); Wed, 31 May 2023 00:02:13 -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 EA1AD11B for ; Tue, 30 May 2023 21:02:09 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-565d6824f2dso68859317b3.0 for ; Tue, 30 May 2023 21:02:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1685505729; x=1688097729; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=v6QTveAwLS+RXrF0pN6prG1FOlU7FfJOhesY8AMEUQ4=; b=RTjAikjKXfCzzzzXmMH2ms1csn4xNxC2KDfgandf99uG3RbmGGHNiyy1B9ygvBUpc8 rpU8PMkmJK3cvKQYUp8XYsFeywHSuSRDpQbXEtp4VE2+jkTacBQhQFnmx4XMl6/MFwNd XAmv17rEtEdYs0Bl1B4PySgRiqRxDJ4/y6i5XoZpSYdEICnUK/ZPZV8XPDbfm8PqFqDV TDn7hbpX8fEWGcZvvPRbNPMlvi9OrTpi3VMgDqULGbBQ8ySJd6UdS7gqqrKPewDw77x8 F5d+9TiQyhXdUUMIVbbdR9+9EPhe0uf+nhf79rB9dSPrnYDkX9CG5iaFYZ+d1WskZdxE P3AA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685505729; x=1688097729; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=v6QTveAwLS+RXrF0pN6prG1FOlU7FfJOhesY8AMEUQ4=; b=T9etgUMatvJGpDIj+Wrva+cQAFwtOYsBF4Ay8S8bdzOB6NdcipZ7kDMBC8TBW5Btqp cfz1rA/A4WSM94sYlj15L4F6bT4p3FewBJr4D5MnNtvPwP/Ua/R5SdY0FJR91QTEd/nj bS/gVa+Rw4WqOuegGdnhljGzFMe+G64prE2qih5fy6RGLY7GsSqIbq9i2Qc9zbmOruF/ s9wXYp/ZH2x7TiibmbGWM7GOAiHytq53lBJyovQJqzDRipqe3+1pRc/O63iSPPG2ajGV Vb2v1Fbwax5kbxpgH/We7JzEG13XbvCyHuno1kvoQvNcQVAnM+t0cJUx905LG1W+QYat FgGQ== X-Gm-Message-State: AC+VfDw69V0sMPsYGDS2gc01XpmyVvitciB4/bUulZR8NPRPUqZ+JvID EdZct1PGx7vXiDfkTh0px+hijgD8uY0= X-Google-Smtp-Source: ACHHUZ5jPpPpVYB4OlWKN/mf41vW77V1YR4lb2MrbmZhSCREbIHJveURgtgOPwxmlsETvhr+LZ7SYiv/DXc= X-Received: from badhri.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:6442]) (user=badhri job=sendgmr) by 2002:a81:431a:0:b0:54c:2409:c306 with SMTP id q26-20020a81431a000000b0054c2409c306mr2486624ywa.6.1685505729173; Tue, 30 May 2023 21:02:09 -0700 (PDT) Date: Wed, 31 May 2023 04:02:02 +0000 In-Reply-To: <20230531040203.19295-1-badhri@google.com> Mime-Version: 1.0 References: <20230531040203.19295-1-badhri@google.com> X-Mailer: git-send-email 2.41.0.rc0.172.g3f132b7071-goog Message-ID: <20230531040203.19295-2-badhri@google.com> Subject: [PATCH v5 2/3] 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, francesco@dolcini.it, alistair@alistair23.me, stephan@gerhold.net, bagasdotme@gmail.com, luca@z3ntu.xyz 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. This commit was reverted due to the crash reported in https://lore.kernel.org/all/ZF4BvgsOyoKxdPFF@francesco-nb.int.toradex.com/. commit 16737e78d190 ("usb: gadget: udc: core: Offload usb_udc_vbus_handler processing") addresses the crash reported. Cc: stable@vger.kernel.org Fixes: 628ef0d273a6 ("usb: udc: add usb_udc_vbus_handler") Signed-off-by: Badhri Jagan Sridharan --- v5 is the first version in this series. --- drivers/usb/gadget/udc/core.c | 148 ++++++++++++++++++++++++---------- 1 file changed, 104 insertions(+), 44 deletions(-) diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index 44a9f32679b5..6ffe5fda8bb7 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -37,6 +37,10 @@ static const 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. @@ -49,6 +53,7 @@ struct usb_udc { bool vbus; bool started; struct work_struct vbus_work; + struct mutex connect_lock; }; static struct class *udc_class; @@ -688,17 +693,9 @@ 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. */ +static int usb_gadget_connect_locked(struct usb_gadget *gadget) + __must_hold(&gadget->udc->connect_lock) { int ret = 0; @@ -707,10 +704,12 @@ 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; @@ -725,22 +724,32 @@ 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. */ +static int usb_gadget_disconnect_locked(struct usb_gadget *gadget) + __must_hold(&gadget->udc->connect_lock) { int ret = 0; @@ -752,10 +761,12 @@ 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; @@ -775,6 +786,30 @@ 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); /** @@ -795,10 +830,11 @@ 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 @@ -808,6 +844,8 @@ 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); @@ -831,6 +869,7 @@ int usb_gadget_activate(struct usb_gadget *gadget) if (!gadget->deactivated) goto out; + mutex_lock(&gadget->udc->connect_lock); gadget->deactivated = false; /* @@ -838,7 +877,8 @@ 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); @@ -1079,19 +1119,22 @@ 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); } static void vbus_event_work(struct work_struct *work) { struct usb_udc *udc = container_of(work, struct usb_udc, vbus_work); - usb_udc_connect_control(udc); + mutex_lock(&udc->connect_lock); + usb_udc_connect_control_locked(udc); + mutex_unlock(&udc->connect_lock); } /** @@ -1139,7 +1182,7 @@ 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 @@ -1150,8 +1193,11 @@ 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; @@ -1168,7 +1214,7 @@ 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 @@ -1177,8 +1223,11 @@ 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"); @@ -1337,6 +1386,7 @@ int usb_add_gadget(struct usb_gadget *gadget) udc->gadget = gadget; gadget->udc = udc; + mutex_init(&udc->connect_lock); udc->started = false; @@ -1539,11 +1589,15 @@ 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; @@ -1575,12 +1629,14 @@ static void gadget_unbind_driver(struct device *dev) kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE); cancel_work_sync(&udc->vbus_work); - 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; @@ -1666,11 +1722,15 @@ 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; From patchwork Wed May 31 04:02:03 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: 687663 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 119ADC77B73 for ; Wed, 31 May 2023 04:02:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234166AbjEaECY (ORCPT ); Wed, 31 May 2023 00:02:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53302 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234071AbjEaECP (ORCPT ); Wed, 31 May 2023 00:02:15 -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 7E92C10E for ; Tue, 30 May 2023 21:02:11 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-565ba5667d5so87991227b3.0 for ; Tue, 30 May 2023 21:02:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1685505730; x=1688097730; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=pTATTkgvxztq9cna9gYn1cQG7KZBsx+3nMydlu+2mlE=; b=al+sJCyOmkaF/6ULIYjfy2VcVPz2C1bJQqcCbgFH/qdd7Y3x3ihhhi+6+rzdnEiUv8 lWpn7yW5seO+rgx/NlgTtfMTIYxkGcVq+TSRBWky9mfQUVCpRWY93+2uS5MuaL75iEDA JQ10HgpgPVDpe+CX3mqaEzbLU4+OSdpKbgU8DULnbEDbNMZ98Xg5KZYbWZrFG/RMGaGR jTnl1guy/5DX8hhiygVrhV049zJ1vcM2cd3XqRd4+0afw78MpemU5/cde1on4KzSuR9e ipRGINz/G0pNg9bKudvd2xs9iSVvrJ7sMHbVynO6oRjOrqbl9maLQHug6QJH1nM5+8b2 OqGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685505730; x=1688097730; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=pTATTkgvxztq9cna9gYn1cQG7KZBsx+3nMydlu+2mlE=; b=JhFILVPq7AFzqt7Um2ZWo27D+zSDml3E9hV3gp55xL0TFlt9wRKfQCcaEwaGQe6tkq Dl83QeHb7INYJdKV9L06xP9pNCV2dFukRtk/D39Q41+tLYSGxWDSD6T2HNgphyKslIsC +hucEq9EyzuRHkXMwWYBQMIGBnOzaTlKI5bdkMn3B3s0sZt2keCubMPSr305o+bIz8Z6 pkhS978xZpSuJzJlC8flcg1WJrKek+wcGoyqYZcFZ5H66kQry51Uhzi7KosxJhp2KcoP 81+duJDRcf8DWErd4+MJnXbNnhW+SuYTHihGPnOM/VOBxs7Olau8DLVNeGw4NsyqFA1W Izww== X-Gm-Message-State: AC+VfDxifDqm0ewVtkr6A7/IrIfpKXblgifJMrpHGR2+KIkpnVRurBq1 ownldY892OU88VEAUaLTD02FoUIXwtw= X-Google-Smtp-Source: ACHHUZ4p0nM25uD1L98TaYBOU36BLpBLGMgEtVGS7cVeo7z12dgaiYwxkeFtmy9TSgo24jh7ThbNKIabBSM= X-Received: from badhri.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:6442]) (user=badhri job=sendgmr) by 2002:a81:b661:0:b0:565:ce25:2693 with SMTP id h33-20020a81b661000000b00565ce252693mr2529499ywk.3.1685505730774; Tue, 30 May 2023 21:02:10 -0700 (PDT) Date: Wed, 31 May 2023 04:02:03 +0000 In-Reply-To: <20230531040203.19295-1-badhri@google.com> Mime-Version: 1.0 References: <20230531040203.19295-1-badhri@google.com> X-Mailer: git-send-email 2.41.0.rc0.172.g3f132b7071-goog Message-ID: <20230531040203.19295-3-badhri@google.com> Subject: [PATCH v5 3/3] usb: gadget: udc: core: Prevent UDC from starting when unbound 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, francesco@dolcini.it, alistair@alistair23.me, stephan@gerhold.net, bagasdotme@gmail.com, luca@z3ntu.xyz Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Badhri Jagan Sridharan , stable Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org UDC should neither be started nor pulled up unless the gadget driver is bound. The new flag "allow_start" is now set by gadget_bind_driver() and cleared by gadget_unbind_driver(). usb_gadget_udc_start_locked() now checks whether allow_start is set before starting the UDC by invoking the ->udc_start() callback. Fixes: fc274c1e9973 ("USB: gadget: Add a new bus for gadgets") Cc: stable Signed-off-by: Badhri Jagan Sridharan --- v5 is the first version in this series. --- drivers/usb/gadget/udc/core.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index 6ffe5fda8bb7..ac9d6186815d 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -37,6 +37,8 @@ static const 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. + * @allow_start: Indicates whether UDC is allowed to start. Set/cleared by gadget_(un)bind_driver() + * after gadget driver is bound or unbound. * @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 @@ -52,6 +54,7 @@ struct usb_udc { struct list_head list; bool vbus; bool started; + bool allow_start; struct work_struct vbus_work; struct mutex connect_lock; }; @@ -1204,6 +1207,9 @@ static inline int usb_gadget_udc_start_locked(struct usb_udc *udc) if (udc->started) { dev_err(&udc->dev, "UDC had already started\n"); return -EBUSY; + } else if (!udc->allow_start) { + dev_err(&udc->dev, "UDC not allowed to start. Is gadget driver bound ?\n"); + return -EIO; } ret = udc->gadget->ops->udc_start(udc->gadget, udc->driver); @@ -1590,6 +1596,7 @@ static int gadget_bind_driver(struct device *dev) goto err_bind; mutex_lock(&udc->connect_lock); + udc->allow_start = true; ret = usb_gadget_udc_start_locked(udc); if (ret) { mutex_unlock(&udc->connect_lock); @@ -1630,6 +1637,7 @@ static void gadget_unbind_driver(struct device *dev) cancel_work_sync(&udc->vbus_work); mutex_lock(&udc->connect_lock); + udc->allow_start = false; usb_gadget_disconnect_locked(gadget); usb_gadget_disable_async_callbacks(udc); if (gadget->irq)