On Thu, 21 Feb 2013, Ulf Hansson wrote: > On 20 February 2013 14:19, Mark Brown > <[email protected]> wrote: > > On Fri, Feb 15, 2013 at 12:56:32PM +0000, Lee Jones wrote: > > > >> +static int ab8500_gpadc_suspend(struct device *dev) > >> +{ > >> + struct ab8500_gpadc *gpadc = dev_get_drvdata(dev); > >> + > >> + mutex_lock(&gpadc->ab8500_gpadc_lock); > >> + > >> + pm_runtime_get_sync(dev); > >> + > >> + regulator_disable(gpadc->regu); > >> + return 0; > >> +} > > > > This doesn't look especially sane... You're doing a runtime get, taking > > the lock without releasing it and disabling the regulator. This is > > *very* odd, both the changelog and the code need to explain what's going > > on and why it's safe in a lot more detail here. > > You need to do pm_runtime_get_sync to be able to make sure resources > (which seems to be only the regulator) are safe to switch off. To my > understanding this is a generic way to use for being able to switch > off resources at a device suspend when runtime pm is used in > conjunction. > > Regarding the mutex, I can't tell the reason behind it. It seems > strange but not sure.
Daniel, any thoughts? I'm happy to fixup, once I have the full story. -- Lee Jones Linaro ST-Ericsson Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
