From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753112AbaBXIFC (ORCPT ); Mon, 24 Feb 2014 03:05:02 -0500 Received: from mx0b-0016f401.pphosted.com ([67.231.156.173]:27347 "EHLO mx0b-0016f401.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752415AbaBXID0 (ORCPT ); Mon, 24 Feb 2014 03:03:26 -0500 From: Neil Zhang To: , , , CC: Neil Zhang Subject: [PATCH 3/6] usb: gadget: mv_udc: clear corresponding interrupt when flush fifo Date: Mon, 24 Feb 2014 16:03:13 +0800 Message-ID: <1393228996-14787-4-git-send-email-zhangwm@marvell.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1393228996-14787-1-git-send-email-zhangwm@marvell.com> References: <1393228996-14787-1-git-send-email-zhangwm@marvell.com> MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.11.87,1.0.14,0.0.0000 definitions=2014-02-23_03:2014-02-21,2014-02-23,1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=7.0.1-1305240000 definitions=main-1402230265 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The interruts are useless when this endpoint is going to be flushed. Especially in the enumeration phase, let's take get device description for example. 1. Device doesn't ACK the status package from host in time due to irq is disabled by some module. 2. Host find no ACK in time, and send another request. 3. Device gets the chance to handle the interrupt, the sequence is as following. a. Flush pending requests in ep0. b. Queue a request in ep0 according to host's request and change the ep0 state to DATA_STATE_XMIT. c. Handle the pending interrupt for the last status package. But actually it will check the new added request instead of the status package and because of wront ep0 state, device will request an unexpected status package from host. d. The ep0 state is going mad. The solution is that we need clear the pending corresponding interrupt as well as flush endpoint. Signed-off-by: Neil Zhang --- drivers/usb/gadget/mv_udc_core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/usb/gadget/mv_udc_core.c b/drivers/usb/gadget/mv_udc_core.c index 657ac5c..d5a9bdf 100644 --- a/drivers/usb/gadget/mv_udc_core.c +++ b/drivers/usb/gadget/mv_udc_core.c @@ -692,6 +692,8 @@ static void mv_ep_fifo_flush(struct usb_ep *_ep) } loops--; } while (readl(&udc->op_regs->epstatus) & bit_pos); + + writel(bit_pos, &udc->op_regs->epcomplete); } /* queues (submits) an I/O request to an endpoint */ -- 1.7.9.5