From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Shevchenko Subject: Re: [PATCH] i2c: designware: Do nothing in system suspend/resume when RT suspended Date: Tue, 20 Jun 2017 19:08:58 +0300 Message-ID: <1497974938.22624.170.camel@linux.intel.com> References: <20170330120444.12499-1-jarkko.nikula@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Return-path: Received: from mga07.intel.com ([134.134.136.100]:7484 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750773AbdFTQNh (ORCPT ); Tue, 20 Jun 2017 12:13:37 -0400 In-Reply-To: Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: Ulf Hansson , Jarkko Nikula , John Stultz Cc: "linux-i2c@vger.kernel.org" , "linux-pm@vger.kernel.org" , Wolfram Sang , "Rafael J . Wysocki" , Mika Westerberg On Tue, 2017-06-20 at 15:07 +0200, Ulf Hansson wrote: > On 16 June 2017 at 15:49, Ulf Hansson wrote: > > Jarkko, Andy, > > > > I just wanted to mention that I haven't forgot about this, I am > > doing > > the final changes for the ACPI PM domain at this very moment, > > however > > I need a couple of more days more before I can post something. > > > > I have now published a branch at: > > git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc.git > acpi_pm_domain_wip > > It contains both changes for the i2c designware platform driver and > for the ACPI PM domain. If you by coincidence happen to have slack > time (probably not), then please try it out. > > The branch is based upon today's version of Rafael's pm tree linux- > next branch. > > If everything goes well, I intend to post the patches after some more > tests. > I have gone through the series briefly. My concern is a quite nasty bug we have workaround for in acpi_lpss.c, i.e. auto power gating of DesignWare DMA on Intel Braswell (CherryTrail) platforms when it's enumerated via ACPI. Below is the sequence to test if it works and survives removal and system sleep (lpss-power.sh is the script which shows a power state of selected devices along with PMC Atom status registers and runtime PM): 0 lpss-power.sh     1 mount -t debugfs none /sys/kernel/debug    2 lpss-power.sh     3 modprobe i2c-designware-platform    4 lpss-power.sh     5 modprobe sdhci-acpi    6 lpss-power.sh     7 lsmod    8 modprobe dw-dmac    9 lpss-power.sh    10 modprobe -r dw-dmac   11 lpss-power.sh    12 modprobe dw-dmac   13 lpss-power.sh    14 rtcwake -m mem -s3   15 lpss-power.sh    16 modprobe -r dw-dmac   17 lpss-power.sh    18 modprobe dw-dmac   19 lpss-power.sh    20 stty -F /dev/ttyS2 921600   21 dmesg > /dev/ttyS2   22 cat /proc/interrupts    23 cat < /dev/ttyS1   24 lpss-power.sh    25 cat < /dev/ttyS1 &   26 lpss-power.sh    27 rtcwake -m mem -s3   28 lpss-power.sh   29 fg   30 lpss-power.sh  Be aware that DMA is not enabled for I2C! -- Andy Shevchenko Intel Finland Oy