Re: [RFT][PATCH v2 2/2] PM / i2c: designware: Clean up system sleep handling without ACPI

Mika Westerberg
2017-09-05T15:27:15Z

On Tue, Sep 05, 2017 at 05:04:21PM +0200, Rafael J. Wysocki wrote:
> On Tuesday, September 5, 2017 5:07:44 PM CEST Mika Westerberg wrote:
> > On Tue, Sep 05, 2017 at 04:55:44PM +0200, Rafael J. Wysocki wrote:
> > > On Tuesday, September 5, 2017 4:58:35 PM CEST Mika Westerberg wrote:
> > > > On Tue, Sep 05, 2017 at 04:46:11PM +0200, Rafael J. Wysocki wrote:
> > > > > On Tuesday, September 5, 2017 4:45:11 PM CEST Mika Westerberg wrote:
> > > > > > On Mon, Sep 04, 2017 at 12:01:54PM +0200, Rafael J. Wysocki wrote:
> > > > > > > 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_RUNTIME_PM_OPS(dw_i2c_plat_runtime_suspend,
> > > > > > > - dw_i2c_plat_resume,
> > > > > > > - NULL)
> > > > > > > + SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
> > > > > >
> > > > > > This seems to cause problem with intel-lpss MFD driver because it uses
> > > > > > .suspend() and .resume() instead of .suspend_late() and .resume_early().
> > > > >
> > > > > OK, so there is one more dependency here.
> > > > >
> > > > > Can you please point me to this code?
> > > >
> > > > It is in drivers/mfd/intel-lpss.c. See intel_lpss_resume().
> > > >
> > >
> > > Looking at it, but I don't quite see how this is related to the
> > > i2c-designware-platedv suspend/resume ...
> >
> > intel-lpss is the parent device for i2c-designware-platdrv. It is
> > supposed to handle all LPSS specific stuff, like bringing the PCI device
> > out of reset before the i2c-designware-platdrv does its own resume
> > things.
>
> Yes, I see.
>
> OK, so what about moving its suspend/resume to the late/early stages?
>
> Would the parent of it be confused?

It seems to work. I did following change and now suspend/resume works
fine with your patch series.

diff --git a/drivers/mfd/intel-lpss.h b/drivers/mfd/intel-lpss.h
index 694116630ffa..c987f7fe6c74 100644
--- a/drivers/mfd/intel-lpss.h
+++ b/drivers/mfd/intel-lpss.h
@@ -38,8 +38,8 @@ int intel_lpss_resume(struct device *dev);
#ifdef CONFIG_PM_SLEEP
#define INTEL_LPSS_SLEEP_PM_OPS \
.prepare = intel_lpss_prepare, \
- .suspend = intel_lpss_suspend, \
- .resume = intel_lpss_resume, \
+ .suspend_late = intel_lpss_suspend, \
+ .resume_early = intel_lpss_resume, \
.freeze = intel_lpss_suspend, \
.thaw = intel_lpss_resume, \
.poweroff = intel_lpss_suspend, \