From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932583AbaEGJxz (ORCPT ); Wed, 7 May 2014 05:53:55 -0400 Received: from mga11.intel.com ([192.55.52.93]:60980 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932073AbaEGJxy (ORCPT ); Wed, 7 May 2014 05:53:54 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,1001,1389772800"; d="scan'208";a="527703175" Date: Wed, 7 May 2014 17:53:44 -0400 From: Zhuang Jin Can To: Felipe Balbi Cc: linux-usb@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, liping.zhou@intel.com, david.a.cohen@linux.intel.com Subject: [PATCH] usb: dwc3: ep0: fix delayed status is queued too early Message-ID: <20140507215344.GH19925@intel.com> Reply-To: jin.can.zhuang@intel.com MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A delayed status request may be queued before composite framework returns USB_GADGET_DELAYED_STATUS, because the thread queueing the request can run on a different core in parallel with the control request irq. SETUP XferComplete IRQ fsg_main_thread ---------------------- --------------- | | spin_lock_irqsave(&dwc->lock) sleeping | | ... ... dwc3_ep0_inspect_setup() | | | dwc3_ep0_delegate_req() | | | ... | spin_unlock(&dwc->lock); | | | fsg_set_alt() ======> Signal Wakeup ====> | | | other gadgets->set_alt() handle exception | | | usb_composite_setup_continue() | | | spin_lock_irqsave(&dwc->lock) | __dwc3_gadget_ep0_queue() | delay_status is false | spin_unlock_irqrestore(&dwc->lock) | | | sleeping spin_lock(&dwc->lock); | | | delayed_status=true | | | STATUS XferNotReady IRQ ------------------------ | dwc3_ep0_xfernotready() | delayed_status is true, return; The result is the status packet will never be transferred, and delayed_status is not cleared. Signed-off-by: Zhuang Jin Can Reported-by: Zhou Liping --- drivers/usb/dwc3/ep0.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c index 21a3520..07292c0 100644 --- a/drivers/usb/dwc3/ep0.c +++ b/drivers/usb/dwc3/ep0.c @@ -1020,7 +1020,11 @@ static void dwc3_ep0_xfernotready(struct dwc3 *dwc, if (dwc->delayed_status) { WARN_ON_ONCE(event->endpoint_number != 1); dev_vdbg(dwc->dev, "Mass Storage delayed status\n"); - return; + + if (list_empty(&dwc->eps[0]->request_list)) + return; + else + dwc->delayed_status = false; } dwc3_ep0_do_control_status(dwc, event); -- 1.7.9.5