* Brian Norris <briannorris@xxxxxxxxxxxx> [171207 00:32]: > On Wed, Dec 06, 2017 at 04:17:54PM -0800, Tony Lindgren wrote: > > * Brian Norris <briannorris@xxxxxxxxxxxx> [171206 19:36]: > > > By the way, it seems pretty ambiguous how we want to handle things like > > > (a) multiple devices sharing the same WAKE# > > > (b) systems where a slot is swappable > > > > > > For (a), the main problem is that if we have to repeat the interrupt > > > definition in multiple devices, then we have to deal with something like > > > IRQF_SHARED. That can be done, but it makes it much harder to use the > > > dedicated wakeirq helpers. > > > > This will get messy, let's not go there :) That is unless the hardware > > really has a single interrupt wired to multiple devices. And in that > > case almost certainly a custom interrupt handler is needed. > > As Rafael mentioned, the spec doesn't clearly delineate a required > hierarchy to the WAKE# pin, and it's certainly possible to share it. I'm > fine dodging that question for now, and only writing said custom > interrupt handler if/when needed. OK if the WAKE# pin is shared then PCI (or hardware specific?) code needs to figure out from where it came from. > But device tree bindings are "forever", so it seems reasonable to at > least agree how it should be defined. Well that's why we're just using the existing interrupts-extended binding there :) It does not leave out the option for shared interrupts, it's just that drivers/base/power/wakeirq.c can't deal with them in a sane way or at least we'd have to add a flag to not enable/disable the wakeirq automatically. Regards, Tony
