From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753628AbbETMmO (ORCPT ); Wed, 20 May 2015 08:42:14 -0400 Received: from mx0b-0016f401.pphosted.com ([67.231.156.173]:41102 "EHLO mx0b-0016f401.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752660AbbETMmG (ORCPT ); Wed, 20 May 2015 08:42:06 -0400 Date: Wed, 20 May 2015 20:38:10 +0800 From: Jisheng Zhang To: Mika Westerberg , CC: , , Subject: Re: [PATCH] i2c: designware: separate ops for system_sleep_pm and runtime_pm Message-ID: <20150520203810.2fa5b489@xhacker> In-Reply-To: <20150520203430.24edd2a8@xhacker> References: <1431693099-2292-1-git-send-email-jszhang@marvell.com> <20150518082823.GH1490@lahna.fi.intel.com> <20150519203242.74617ad6@xhacker> <20150519131516.GO1490@lahna.fi.intel.com> <20150520193422.73de7d90@xhacker> <20150520121506.GU1490@lahna.fi.intel.com> <20150520203430.24edd2a8@xhacker> X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.25; x86_64-pc-linux-gnu) Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.14.151,1.0.33,0.0.0000 definitions=2015-05-20_03:2015-05-19,2015-05-20,1970-01-01 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=7.0.1-1402240000 definitions=main-1505200167 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 20 May 2015 20:34:30 +0800 Jisheng Zhang wrote: > Dear Mika, > > On Wed, 20 May 2015 15:15:06 +0300 > Mika Westerberg wrote: > > > On Wed, May 20, 2015 at 07:34:22PM +0800, Jisheng Zhang wrote: > > > Sorry for confusion. Considering one platform which doesn't support power off > > > the i2c host but it can disable the host's clock. So in such platform, when > > > the host is runtime suspended, its clock is disabled, then i2c_dw_disable() will > > > hang when s2ram. > > > > Right. This happens also when the platform powers off the device. > > > > > Except using the runtime pm API to ensure the host is in > > > a correct state, is there any other solution? AFAIK, 'dev->power.direct_complete' > > > doesn't help such case. > > > > What I had in mind is something like below: > > > > static int i2c_dw_prepare(struct device *dev) > > { > > return pm_runtime_suspended(dev); > > } > > > > static void i2c_dw_complete(struct device *dev) > > { > > if (dev->power.direct_complete) > > pm_request_resume(dev); > > } > > > > In other words it checks if the device is already runtime suspended and > > prevents ->suspend() etc. from being called. > > What amazing! I wrote the same code as yours after sending out the last email. > > > > > If that does not work (I didn't try as this problem does not exist on > > It works! How to submit the patch? Do you mind if I cook the patch and add > you signed-off? > PS: If you cook the patch instead, feel free to add my acked-by and tested-by Thanks a lot for the direct_complete idea, Jisheng