From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Rajat Jain <rajatja@google.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
        Jarkko Nikula <jarkko.nikula@linux.intel.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Mika Westerberg <mika.westerberg@linux.intel.com>,
        Wolfram Sang <wsa@the-dreams.de>,
        linux-i2c <linux-i2c@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Lee Jones <lee.jones@linaro.org>,
        "Wysocki, Rafael J" <rafael.j.wysocki@intel.com>,
        Linux PM <linux-pm@vger.kernel.org>, Len Brown <len.brown@intel.com>,
        Furquan Shaikh <furquan@google.com>, Rajat Jain <rajatxjain@gmail.com>
Subject: Re: [PATCH 1/2] i2c: designware: switch to suspend_late/resume_early
Date: Thu, 21 Sep 2017 16:11:19 +0200
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On Thursday, September 21, 2017 3:13:56 AM CEST Rajat Jain wrote:
> On Wed, Sep 20, 2017 at 5:24 PM, Rafael J. Wysocki <rafael@kernel.org> wrote:
> > On Thu, Sep 21, 2017 at 12:31 AM, Rajat Jain <rajatja@google.com> wrote:
> >> Ref: https://lkml.org/lkml/2017/9/19/649
> >>
> >> The bus controllers should suspend the bus operations only after
> >> all of the devices on the bus have suspended their device
> >> completely. Since the i2c_client drivers could be talking to
> >> their devices in their suspend_late() calls, lets ensure that the
> >> bus is alive by that time. Thus moving the controller suspend logic to
> >> suspend_late().
> >>
> >> Signed-off-by: Rajat Jain <rajatja@google.com>
> >> ---
> >>  drivers/i2c/busses/i2c-designware-platdrv.c | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
> >> index 0e65b97842b4..66dd7f844c40 100644
> >> --- a/drivers/i2c/busses/i2c-designware-platdrv.c
> >> +++ b/drivers/i2c/busses/i2c-designware-platdrv.c
> >> @@ -468,7 +468,7 @@ static int dw_i2c_plat_suspend(struct device *dev)
> >>  static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
> >>         .prepare = dw_i2c_plat_prepare,
> >>         .complete = dw_i2c_plat_complete,
> >> -       SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
> >> +       SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
> >>         SET_RUNTIME_PM_OPS(dw_i2c_plat_runtime_suspend,
> >>                            dw_i2c_plat_resume,
> >>                            NULL)
> >
> > No, you can't just do that.
> >
> > I sent patches to do it properly before my trip to LA last week, it
> > shouldn't be overly difficult to find them in the mailing list
> > archives.  I can look them up tomorrow if need be.
> 
> Thanks, I am guessing you mean this?
> 
> https://patchwork.kernel.org/patch/9939807/

Yes, that's what I mean.

Thanks,
Rafael