Messages in this thread | | | Date | Fri, 22 Feb 2013 07:55:35 +0000 | From | Lee Jones <> | Subject | Re: [PATCH 01/35] mfd: ab8500-gpadc: Implemented suspend/resume |
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On Thu, 21 Feb 2013, Ulf Hansson wrote:
> On 20 February 2013 14:19, Mark Brown > <broonie@opensource.wolfsonmicro.com> 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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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