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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,UNPARSEABLE_RELAY 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 EC950C43381 for ; Mon, 4 Mar 2019 06:58:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA3D120823 for ; Mon, 4 Mar 2019 06:58:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726158AbfCDG6L (ORCPT ); Mon, 4 Mar 2019 01:58:11 -0500 Received: from Mailgw01.mediatek.com ([1.203.163.78]:30822 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1725981AbfCDG6L (ORCPT ); Mon, 4 Mar 2019 01:58:11 -0500 X-UUID: 873b889c21174a91b57c226523e36ca3-20190304 X-UUID: 873b889c21174a91b57c226523e36ca3-20190304 Received: from mtkcas32.mediatek.inc [(172.27.4.253)] by mailgw01.mediatek.com (envelope-from ) (mailgw01.mediatek.com ESMTP with TLS) with ESMTP id 1125917710; Mon, 04 Mar 2019 14:58:07 +0800 Received: from MTKCAS36.mediatek.inc (172.27.4.186) by MTKMBS33N2.mediatek.inc (172.27.4.76) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Mon, 4 Mar 2019 14:58:05 +0800 Received: from [10.17.3.153] (172.27.4.253) by MTKCAS36.mediatek.inc (172.27.4.170) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Mon, 4 Mar 2019 14:58:04 +0800 Message-ID: <1551682684.2210.67.camel@mhfsdcap03> Subject: Re: [PATCH v3 10/12] hikey960: Support usb functionality of Hikey960 From: Chunfeng Yun To: Andy Shevchenko CC: Yu Chen , USB , devicetree , Linux Kernel Mailing List , John Stultz , Suzhuangluan , Kongfei , , , , "Yao Chen" , , , songxiaowei , xu yiping , , , , Arnd Bergmann , "Greg Kroah-Hartman" , Binghui Wang , Heikki Krogerus Date: Mon, 4 Mar 2019 14:58:04 +0800 In-Reply-To: References: <20190302090505.65542-1-chenyu56@huawei.com> <20190302090505.65542-11-chenyu56@huawei.com> <1551664069.2210.64.camel@mhfsdcap03> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-MTK: N Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org hi, On Mon, 2019-03-04 at 08:50 +0200, Andy Shevchenko wrote: > On Mon, Mar 4, 2019 at 3:47 AM Chunfeng Yun wrote: > > On Sat, 2019-03-02 at 17:05 +0800, Yu Chen wrote: > > > > + hisi_hikey_usb->role_sw = usb_role_switch_get(dev); > > > + if (!hisi_hikey_usb->role_sw) > > > + return -EPROBE_DEFER; > > Here return EPROBE_DEFFER means the related device_connection is > > registered after this probe is called, right? > > if not, use IS_ERR_OR_NULL then return PTR_ERR is enough > > How enough? If return value is NULL it would be transformered to 0, > which is success return code from the ->probe() which means we will > have ->probed() and not functional device. > You are right:) > Am I missing something? >