Re: [RFC PATCH 4/4] sdio: pm: set device's power state after driver runtime suspended it

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Saturday 20 of October 2012 15:15:41 Aaron Lu wrote:
> On Fri, Oct 19, 2012 at 08:08:38PM +0200, Rafael J. Wysocki wrote:
> > On Friday 19 of October 2012 01:39:25 Rafael J. Wysocki wrote:
> > > On Friday 12 of October 2012 11:12:41 Aaron Lu wrote:
> > > > In sdio bus level runtime callback function, after call the driver's
> > > > runtime suspend callback, we will check if the device supports a
> > > > platform level power management, and if so, a proper power state is
> > > > chosen by the corresponding platform callback and then set.
> > > > 
> > > > Platform level runtime wakeup is also set, if device is enabled for
> > > > runtime wakeup by its driver, it will be armed the ability to generate
> > > > a wakeup event by the platform.
> > > > 
> > > > Signed-off-by: Aaron Lu <aaron.lu@intel.com>
> > > > ---
> > > >  drivers/mmc/core/sdio_bus.c | 49 +++++++++++++++++++++++++++++++++++++++++++--
> > > >  1 file changed, 47 insertions(+), 2 deletions(-)
> > > > 
> > > > diff --git a/drivers/mmc/core/sdio_bus.c b/drivers/mmc/core/sdio_bus.c
> > > > index aaec9e2..d83dea8 100644
> > > > --- a/drivers/mmc/core/sdio_bus.c
> > > > +++ b/drivers/mmc/core/sdio_bus.c
> > > > @@ -23,6 +23,7 @@
> > > >  
> > > >  #include "sdio_cis.h"
> > > >  #include "sdio_bus.h"
> > > > +#include "sdio.h"
> > > >  #include "sdio_acpi.h"
> > > >  
> > > >  /* show configuration fields */
> > > > @@ -194,10 +195,54 @@ static int sdio_bus_remove(struct device *dev)
> > > >  }
> > > >  
> > > >  #ifdef CONFIG_PM
> > > > +
> > > > +static int sdio_bus_runtime_suspend(struct device *dev)
> > > > +{
> > > > +	int ret;
> > > > +	sdio_power_t state;
> > > > +
> > > > +	ret = pm_generic_runtime_suspend(dev);
> > > > +	if (ret)
> > > > +		goto out;
> > > > +
> > > > +	if (!platform_sdio_power_manageable(dev))
> > > > +		goto out;
> > > > +
> > > > +	platform_sdio_run_wake(dev, true);
> > > > +
> > > > +	state = platform_sdio_choose_power_state(dev);
> > > > +	if (state == SDIO_POWER_ERROR) {
> > > > +		ret = -EIO;
> > > > +		goto out;
> > > > +	}
> > > > +
> > > > +	ret = platform_sdio_set_power_state(dev, state);
> > > > +
> > > > +out:
> > > > +	return ret;
> > > > +}
> > > > +
> > > > +static int sdio_bus_runtime_resume(struct device *dev)
> > > > +{
> > > > +	int ret;
> > > > +
> > > > +	if (platform_sdio_power_manageable(dev)) {
> > > > +		platform_sdio_run_wake(dev, false);
> > > > +		ret = platform_sdio_set_power_state(dev, SDIO_D0);
> > > > +		if (ret)
> > > > +			goto out;
> > > > +	}
> > > > +
> > > > +	ret = pm_generic_runtime_resume(dev);
> > > > +
> > > > +out:
> > > > +	return ret;
> > > > +}
> > > > +
> > > 
> > > Most likely we will need to make analogous changes for other bus types that
> > > don't support power management natively, like platform, SPI, I2C etc.  In all
> > > of them the _runtime_suspend() and _runtime_resume() routine will look
> > > almost exactly the same except for the platform_sdio_ prefix.
> > > 
> > > For this reason, I think it would be better to simply define two functions
> > > acpi_pm_runtime_suspend() and acpi_pm_runtime_resume() that will do all of
> > > the ACPI-specific operations related to runtime suspend/resume.  Then, we
> > > will be able to use these functions for all of the bus types in question
> > > in the same way (we may also need to add analogous functions for system
> > > suspend/resume handling).
> > 
> > Something like in the (totally untested) patch below.
> 
> Looks good to me.
> I'll test the code and put it into v2 of the patchset with your
> sign-off, is it OK?

I'd rather do it a bit differently in the signed-off version (I'm working
on these patches, they should be ready around Tuesday), but if you can test
it in its current form, that'd be useful too.

Thanks,
Rafael


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.