[...] > > > > Well is it actually a problem to not specify the flag? I guess it's just > > a potential problem if the genpd is ever powered off, but given that the > > governor decides to leave it always enabled it doesn't actually matter? > > So it's not really fixing anything besides silencing a harmless warning? > > The warning is indeed harmless. > > The "interesting" case is the case where no warning is printed, as no > IRQ-safe device is present. In that case, the absence of the > GENPD_FLAG_ALWAYS_ON flag means that the core PM Domain code will > consider the domain for power-off, and will loop over all devices part > of it, which is suboptimal. Setting the flag avoids that. > > Thanks for your continued questions, it made me realize I need to add more > meat to the description to these "simple" patches! > > For the PM people: would it make sense to add a > WARN(!genpd->power_off && !genpd_is_always_on(genpd), "...") check to > pm_genpd_init()? > Or set GENPD_FLAG_ALWAYS_ON automatically if !genpd->power_off?
Well, wouldn't it be possible that the power is provided through a master domain, thus not having the ->power_off() callback assigned for the subdomain is perfectly fine, even without having GENPD_FLAG_ALWAYS_ON not set. Kind regards Uffe
