On 22 February 2013 11:38, Mark Brown <broo...@opensource.wolfsonmicro.com> wrote: > On Thu, Feb 21, 2013 at 11:45:08PM +0100, Ulf Hansson wrote: >> On 20 February 2013 14:19, Mark Brown > >> > 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. > > Are you sure this actually does what you think it does, especially when > run on modern kernels?
Not sure, what you are thinking of more precisely here. Runtime pm has been in the kernel for quite some time now. Anyway, to make it a bit clearer, we switch the regulator on/off at the runtime suspend/resume callbacks. We want to take similar actions in device suspend/resume. To accomplish this a pm_runtime_get_sync is done in suspend and vice verse in resume, otherwise you can not safely handle the regulator. Kind regards Ulf Hansson -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/