Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750993AbaBYHLq (ORCPT ); Tue, 25 Feb 2014 02:11:46 -0500 Received: from mx0a-0016f401.pphosted.com ([67.231.148.174]:6626 "EHLO mx0a-0016f401.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750706AbaBYHLp (ORCPT ); Tue, 25 Feb 2014 02:11:45 -0500 From: Neil Zhang To: Peter Chen CC: "balbi@ti.com" , "gregkh@linuxfoundation.org" , "linux-usb@vger.kernel.org" , "linux-kernel@vger.kernel.org" Date: Mon, 24 Feb 2014 23:11:39 -0800 Subject: RE: [PATCH 2/6] usb: gadget: mv_udc: disable HW zlt for ep0 Thread-Topic: [PATCH 2/6] usb: gadget: mv_udc: disable HW zlt for ep0 Thread-Index: AQHPMTdfHn6q0sLFtkmQnfSG9aPWEJrFsrSA//+qwwCAABEV4IAAIBBQ Message-ID: <175CCF5F49938B4D99B2E3EF7F558EBE54EC4135A5@SC-VEXCH4.marvell.com> References: <1393228996-14787-1-git-send-email-zhangwm@marvell.com> <1393228996-14787-3-git-send-email-zhangwm@marvell.com> <20140225011839.GD7540@shlinux1.ap.freescale.net> <175CCF5F49938B4D99B2E3EF7F558EBE54EC413563@SC-VEXCH4.marvell.com> <6ad74d797ecc473f922ffdb58c3e9c70@BN1PR03MB235.namprd03.prod.outlook.com> In-Reply-To: <6ad74d797ecc473f922ffdb58c3e9c70@BN1PR03MB235.namprd03.prod.outlook.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="gb2312" MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.11.87,1.0.14,0.0.0000 definitions=2014-02-25_01:2014-02-25,2014-02-25,1970-01-01 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-1402240223 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id s1P7CXrK020394 > -----Original Message----- > From: Peter Chen [mailto:Peter.Chen@freescale.com] > Sent: 2014??2??25?? 13:15 > To: Neil Zhang > Cc: balbi@ti.com; gregkh@linuxfoundation.org; linux-usb@vger.kernel.org; > linux-kernel@vger.kernel.org > Subject: RE: [PATCH 2/6] usb: gadget: mv_udc: disable HW zlt for ep0 > > > > > > > On Mon, Feb 24, 2014 at 04:03:12PM +0800, Neil Zhang wrote: > > > > Hardware zlt will try to send the zero length packet automatically > > > > when the data transferd is multiple times of max packet, this will > > > > cause issues on Windows. > > > > So let's disable HW zlt by default. > > > > > > Would you have description that what kinds of issue on Windows if > > > zlt is is selected? > > > > > > > Enumeration will fail. > > > > What causes enumeration fail, why it does not occur before? > A unexpected zero packet cause enumeration fail. It's not easy that the descriptor is actually 1024 bytes, so not easy to be found. > Peter Best Regards, Neil Zhang ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?