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 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 1B3AAC3A59E for ; Wed, 21 Aug 2019 16:46:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E04232339F for ; Wed, 21 Aug 2019 16:46:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566406011; bh=4Jm8zjZi8LCwfW7kAZQjrdlT66K1EqlB+1IQPAQRhew=; h=Subject:To:From:Date:List-ID:From; b=fcZBS103QpiugmyXOHc3grrnGBtnUOtT4UFC9OGPvNhXUGxFUQa3RCX4zN31w2j+e fzJgQ5JwEm0ns7eswcbXK0ClqGdcMSLXmmv1DmBp0BI3i45SckXz7li0YhTkM9pcvd X3l+t/49QmcUY5hp/pb3yLmgan67qF83JF7cGxu8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729587AbfHUQqs (ORCPT ); Wed, 21 Aug 2019 12:46:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:59730 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729543AbfHUQqr (ORCPT ); Wed, 21 Aug 2019 12:46:47 -0400 Received: from localhost (wsip-184-188-36-2.sd.sd.cox.net [184.188.36.2]) (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 64CA72339F; Wed, 21 Aug 2019 16:46:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566406006; bh=4Jm8zjZi8LCwfW7kAZQjrdlT66K1EqlB+1IQPAQRhew=; h=Subject:To:From:Date:From; b=NLrDHahtuCXwlgQq0Tm6It2E+WQ8z1zOR8wCflaHMuLWCNa0i9tLJjzCTpZzkb4ur Bm08MI43y6DOhfEQqlZ4Oq6iSEcBphq4BrA63OYIgHuHXuqYLw+0pWJyAtGX4hX6BN K+WlekWPilJEcPygUEOGDo5MeDcKF9vAqbXtvCvM= Subject: patch "usb: chipidea: udc: don't do hardware access if gadget has stopped" added to usb-linus To: peter.chen@nxp.com, gregkh@linuxfoundation.org, stable@vger.kernel.org From: Date: Wed, 21 Aug 2019 09:46:44 -0700 Message-ID: <156640600412223@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: chipidea: udc: don't do hardware access if gadget has stopped 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 cbe85c88ce80fb92956a0793518d415864dcead8 Mon Sep 17 00:00:00 2001 From: Peter Chen Date: Tue, 20 Aug 2019 02:07:58 +0000 Subject: usb: chipidea: udc: don't do hardware access if gadget has stopped After _gadget_stop_activity is executed, we can consider the hardware operation for gadget has finished, and the udc can be stopped and enter low power mode. So, any later hardware operations (from usb_ep_ops APIs or usb_gadget_ops APIs) should be considered invalid, any deinitializatons has been covered at _gadget_stop_activity. I meet this problem when I plug out usb cable from PC using mass_storage gadget, my callstack like: vbus interrupt->.vbus_session-> composite_disconnect ->pm_runtime_put_sync(&_gadget->dev), the composite_disconnect will call fsg_disable, but fsg_disable calls usb_ep_disable using async way, there are register accesses for usb_ep_disable. So sometimes, I get system hang due to visit register without clock, sometimes not. The Linux Kernel USB maintainer Alan Stern suggests this kinds of solution. See: http://marc.info/?l=linux-usb&m=138541769810983&w=2. Cc: #v4.9+ Signed-off-by: Peter Chen Link: https://lore.kernel.org/r/20190820020503.27080-2-peter.chen@nxp.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/chipidea/udc.c | 32 ++++++++++++++++++++++++-------- 1 file changed, 24 insertions(+), 8 deletions(-) diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c index 6a5ee8e6da10..67ad40b0a05b 100644 --- a/drivers/usb/chipidea/udc.c +++ b/drivers/usb/chipidea/udc.c @@ -709,12 +709,6 @@ static int _gadget_stop_activity(struct usb_gadget *gadget) struct ci_hdrc *ci = container_of(gadget, struct ci_hdrc, gadget); unsigned long flags; - spin_lock_irqsave(&ci->lock, flags); - ci->gadget.speed = USB_SPEED_UNKNOWN; - ci->remote_wakeup = 0; - ci->suspended = 0; - spin_unlock_irqrestore(&ci->lock, flags); - /* flush all endpoints */ gadget_for_each_ep(ep, gadget) { usb_ep_fifo_flush(ep); @@ -732,6 +726,12 @@ static int _gadget_stop_activity(struct usb_gadget *gadget) ci->status = NULL; } + spin_lock_irqsave(&ci->lock, flags); + ci->gadget.speed = USB_SPEED_UNKNOWN; + ci->remote_wakeup = 0; + ci->suspended = 0; + spin_unlock_irqrestore(&ci->lock, flags); + return 0; } @@ -1303,6 +1303,10 @@ static int ep_disable(struct usb_ep *ep) return -EBUSY; spin_lock_irqsave(hwep->lock, flags); + if (hwep->ci->gadget.speed == USB_SPEED_UNKNOWN) { + spin_unlock_irqrestore(hwep->lock, flags); + return 0; + } /* only internal SW should disable ctrl endpts */ @@ -1392,6 +1396,10 @@ static int ep_queue(struct usb_ep *ep, struct usb_request *req, return -EINVAL; spin_lock_irqsave(hwep->lock, flags); + if (hwep->ci->gadget.speed == USB_SPEED_UNKNOWN) { + spin_unlock_irqrestore(hwep->lock, flags); + return 0; + } retval = _ep_queue(ep, req, gfp_flags); spin_unlock_irqrestore(hwep->lock, flags); return retval; @@ -1415,8 +1423,8 @@ static int ep_dequeue(struct usb_ep *ep, struct usb_request *req) return -EINVAL; spin_lock_irqsave(hwep->lock, flags); - - hw_ep_flush(hwep->ci, hwep->num, hwep->dir); + if (hwep->ci->gadget.speed != USB_SPEED_UNKNOWN) + hw_ep_flush(hwep->ci, hwep->num, hwep->dir); list_for_each_entry_safe(node, tmpnode, &hwreq->tds, td) { dma_pool_free(hwep->td_pool, node->ptr, node->dma); @@ -1487,6 +1495,10 @@ static void ep_fifo_flush(struct usb_ep *ep) } spin_lock_irqsave(hwep->lock, flags); + if (hwep->ci->gadget.speed == USB_SPEED_UNKNOWN) { + spin_unlock_irqrestore(hwep->lock, flags); + return; + } hw_ep_flush(hwep->ci, hwep->num, hwep->dir); @@ -1559,6 +1571,10 @@ static int ci_udc_wakeup(struct usb_gadget *_gadget) int ret = 0; spin_lock_irqsave(&ci->lock, flags); + if (ci->gadget.speed == USB_SPEED_UNKNOWN) { + spin_unlock_irqrestore(&ci->lock, flags); + return 0; + } if (!ci->remote_wakeup) { ret = -EOPNOTSUPP; goto out; -- 2.23.0