On 04:08:52PM Jan 07, Peter De Schrijver wrote: > On Wed, Jan 07, 2015 at 02:27:10PM +0100, Thierry Reding wrote: > > > > Yeah. I plan to have the information of all the clock client of the > > > partitions and > > > the memory clients be defined statically in c source, e.g. pmc-tegra124.c. > > > All modules can declare which domain they belong to in DT. One domain can > > > be really power gated only when no module is awake. Note the clock clients > > > of > > > one domain might not equal to the clocks of the module. The reset is not > > > either. > > > So I don't get the clock and reset from module. How do you think? > > > > This whole situation is quite messy. The above sequence basically means > > that drivers can't reset hardware modules because otherwise they might > > race with the power domain code. It also means that we can't powergate > > The powerdomain framework won't call any powergating method as long as a > module in the domain is still active. So as long as drivers don't try to > reset the hw without having done a pm_runtime_get(), we shouldn't have such > a race? Agree. And as long as the driver has the correct reset procedure, that should be fine to occur between power ungating and gating sequences.
> > > modules on demand because they might be in the same power domain as one > > other module that's still busy. > > > > The powerdomain framework keeps track of which modules are active (by hooking > into runtime pm) and won't try to shutdown a domain unless all modules are > inactive. Yeah. By the way, that means we should start supporting runtime pm for all the modules to use generic power domain. Thanks, Vince > > > How would we handle a situation where a hardware module hangs and we can > > only get it back via a reset? > > > > Cheers, > > Peter. -- 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/