From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757172Ab3LWJDX (ORCPT ); Mon, 23 Dec 2013 04:03:23 -0500 Received: from mailout1.samsung.com ([203.254.224.24]:25764 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751504Ab3LWJDT (ORCPT ); Mon, 23 Dec 2013 04:03:19 -0500 X-AuditID: cbfee691-b7efc6d0000039d3-23-52b7fc557760 Date: Mon, 23 Dec 2013 09:02:51 +0000 (GMT) From: MyungJoo Ham Subject: Re: Re: [PATCH 1/1] extcon: gpio: Add power resume support To: =?euc-kr?Q?=C3=D6=C2=F9=BF=EC?= , Barry Song <21cnbao@gmail.com> Cc: rjying , LKML , RongJun Ying , Binghua Duan Reply-to: myungjoo.ham@samsung.com MIME-version: 1.0 X-MTR: 20131223082751036@myungjoo.ham Msgkey: 20131223082751036@myungjoo.ham X-EPLocale: ko_KR.euc-kr X-Priority: 3 X-EPWebmail-Msg-Type: personal X-EPWebmail-Reply-Demand: 0 X-EPApproval-Locale: X-EPHeader: ML X-EPTrCode: X-EPTrName: X-MLAttribute: X-RootMTR: 20131223082751036@myungjoo.ham X-ParentMTR: X-ArchiveUser: X-CPGSPASS: N Content-type: text/plain; charset=euc-kr MIME-version: 1.0 Message-id: <2741731.123321387789370147.JavaMail.weblogic@epml01> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFupnleLIzCtJLcpLzFFi42JZI2JSpBv6Z3uQwcO5ohaXd81hc2D0+LxJ LoAxissmJTUnsyy1SN8ugSvj8923TAU/FCvu/XzD1MDYotjFyMkhJKAusWjJSTYQW0LARGLZ yj4mCFtM4sK99UBxLqCapYwSF36vZYYp6vv4nhEiMZ9R4lLPBRaQBIuAqsS7fU+Bujk42AT0 JGZ+TgYJCws4S+yc+48dxBYRSJSYs2MOWC+zwCxGiUWvN7BBXKEksWbfK7A5vAKCEidnPmGB WKYqcePgBiaIuJrE63XroI6QkJg1/QIrhM0rMaP9KVS9nMS0r2ugaqQlzs/awAjzzeLvj6Hi /BLHbu8AuxOk98n9YJgxuzd/gQaEgMTUMwehWrUk7j3rhBrPJ7Fm4VsWmDG7Ti1nhum9v2Uu 2JnMAooSU7ofskPYWhJffuxjQ/cWr4CjxO3PrawTGJVnIUnNQtI+C0k7spoFjCyrGEVTC5IL ipPSi0z1ihNzi0vz0vWS83M3MQITw+l/zybuYLx/wPoQYzIwSiYyS4km5wMTS15JvKGxmZGF qYmpsZG5pRlpwkrivOmPkoKEBNITS1KzU1MLUovii0pzUosPMTJxcEo1MK6P3XBZecUvftWr oleKlgkb955lF9G12tEYyK38qyo1753zgR324unxUxWWNzgH3e/zmbvt71Kx5xyXSiXfnnwZ LRSzjd/+xLflN7XKZ1w4whu0NKLiF0u+AEtnc2/5egWG+6yW996dLj+k4ZO+dZ/49iUmfYK7 a5QNRXTzw/dNzX2tZqdXr8RSnJFoqMVcVJwIAIuEOyQiAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmpgk+LIzCtJLcpLzFFi42I5/e/2TN3QP9uDDN7957W4vGsOmwOjx+dN cgGMUWk2GamJKalFCql5yfkpmXnptkrewfHO8aZmBoa6hpYW5koKeYm5qbZKLj4Bum6ZOUBD lRTKEnNKgUIBicXFSvp2NkX5pSWpChn5xSW2StGG5kZ6RgZ6pkZ6hsaxVoYGBkamQDUJaRmf 775lKvihWHHv5xumBsYWxS5GTg4hAXWJRUtOsoHYEgImEn0f3zNC2GISF+6tB4pzAdXMZ5S4 1HOBBSTBIqAq8W7fU6YuRg4ONgE9iZmfk0HCwgLOEjvn/mMHsUUEEiXm7JjDCNLLLDCLUWLR 6w1sEMuUJNbsewU2h1dAUOLkzCcsEMtUJW4c3MAEEVeTeL1uHTNEXEJi1vQLrBA2r8SM9qdQ 9XIS076ugaqRljg/awPc0Yu/P4aK80scu70D7E6Q3if3g2HG7N78BepfAYmpZw5CtWpJ3HvW CTWeT2LNwrcsMGN2nVrODNN7f8tcsDOZBRQlpnQ/ZIewtSS+/NjHhu4tXgFHidufW1knMMrN QpKahaR9FpJ2ZDULGFlWMYqmFiQXFCelVxjqFSfmFpfmpesl5+duYgSnp2cLdzB+OW99iFGA g1GJh5ejZXuQEGtiWXFl7iFGCQ5mJRHe6B/bgoR4UxIrq1KL8uOLSnNSiw8xJgMjcCKzlGhy PjB15pXEGxobm5iZmFqaWBiYmpMmrCTOe/dmUpCQQHpiSWp2ampBahHMFiYOTqkGxnmnHU8t Np+XuOHsYZca3hOp3L5S/087KczeILr5yfSIM+/MH4tMO7miU+Sjk8njWw53lXoOb1Xjv3h2 m3N6d+W8iiNstxqqnkg6p7hEmq7NrFjxO9nh9Oyyf19Cr8c0ykwSTYx7ONHvwv+7azZ0P3rz M7dqywP9GdHbHpnM4T6y+WYOX/Wsh5uUWIozEg21mIuKEwFEAU1VkwMAAA== DLP-Filter: Pass X-CFilter-Loop: Reflected 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 rBN93UGC024856 > On 12/23/2013 05:13 PM, Barry Song wrote: > > 2013/12/23 Chanwoo Choi : > >> On 12/23/2013 04:36 PM, Barry Song wrote: > >>> 2013/12/23 Chanwoo Choi : > >>>> On 12/23/2013 03:10 PM, Barry Song wrote: > >>>>> 2013/12/23 Chanwoo Choi : > >>>>>> On 12/20/2013 05:09 PM, rjying wrote: > >>>>>>> From: Rongjun Ying > >>>>>>> > >>>>>>> After system resume, need send extcon uevent to userspace > >>>>>> > >>>>>> Why did extcon send uevent after wakeup from suspend? > >>>>>> > >>>>>> If extcon cable is attatched or detached on suspend state, > >>>>>> Kernel can detect the interrupt about changed state of extcon. > >>>>> > >>>>> irq controller has lost power in suspend, so there is no pending interrupt. > >>>>> and HW will not pend any interrupt when we hotplug cable during sleep. > >>>> > >>>> No, SoC in suspend state must maintain the minimum power under 1mA > >>>> if completed the power-optimization on suspend state. > >>>> > >>>> If user insert USB cable to target, the external interrupt connected to > >>>> USB port is happened. And kernel would be waked up from suspend state > >>>> to operate proper interrupt handler of external interrupt. > >>> > >>> no. not every USB supports that. that depends on the power domain design of SoC. > >> > >> USB is only example for gpio control in suspend state. > >> > >>> > >>>> > >>>> Also, > >>>> Input subsystem used gpio-keys driver for power button.. > >>>> If user press power button in suspend state, target would be waked up from suspend state. > >>>> It is same case both extcon gpio and gpio-keys of input subsystem. > >>> > >>> no. it depends on the SoC design. many SoC only support 1 special key > >>> which can work as ON-KEY as wakeup source. and this kind of keys might > >>> not be GPIO at all. > >>> there is a special power domain which is still open for it. > >> > >> many SoC? > >> > >> As I knew, most SoC has supported various wakeup source. > >> As you comment, if specific SoC support only one special key > >> for wakeup from suspend state, I think it isn't common. > >> > >> Also, > >> This patch isn't necessary on SoCs which support various wakeup source (e.g., external interrupt). > >> As you comment, this issue has dependecy on specific SoC. Why did you think this common code? > > > > i am not thinking this patch must be common codes but i think the > > extcon should provide common codes to support all chips. that is what > > a framework should consider. > > > > if there is no this or things similar with this, how could extcon > > support the chips which don't support receiving sleep gpio interrupts? > > Sure, subsystem should support all cases related to this issue. > > I'd like to send common patch to support all cases as we discussed. > If some patch support all case, I would review and apply it. > > Chanwoo Choi Dear Barry and Chanwoo, What about having a flag in extcon platform data that describes whether this extcon-gpio requires status double checking at resume or not? Cheers, MyungJoo {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I