On Tue, 10 Feb 2015 16:16:00 +0000 Mark Rutland <mark.rutland@xxxxxxx> wrote: > On Tue, Feb 10, 2015 at 03:52:01PM +0000, Boris Brezillon wrote: > > Hi Mark, > > > > On Tue, 10 Feb 2015 15:36:28 +0000 > > Mark Rutland <mark.rutland@xxxxxxx> wrote: > > > > > Hi Boris, > > > > > > On Thu, Jan 29, 2015 at 10:33:38AM +0000, Boris Brezillon wrote: > > > > Add documentation for the virtual irq demuxer. > > > > > > > > Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx> > > > > Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx> > > > > --- > > > > .../bindings/interrupt-controller/dumb-demux.txt | 41 ++++++++++++++++++++++ > > > > 1 file changed, 41 insertions(+) > > > > create mode 100644 Documentation/devicetree/bindings/interrupt-controller/dumb-demux.txt > > > > > > > > diff --git a/Documentation/devicetree/bindings/interrupt-controller/dumb-demux.txt b/Documentation/devicetree/bindings/interrupt-controller/dumb-demux.txt > > > > new file mode 100644 > > > > index 0000000..b9a7830 > > > > --- /dev/null > > > > +++ b/Documentation/devicetree/bindings/interrupt-controller/dumb-demux.txt > > > > @@ -0,0 +1,41 @@ > > > > +* Virtual Interrupt Demultiplexer > > > > + > > > > +This virtual demultiplexer simply forward all incoming interrupts to its > > > > +enabled/unmasked children. > > > > +It is only intended to be used by hardware that do not provide a proper way > > > > +to demultiplex a source interrupt, and thus have to wake all their children > > > > +up so that they can possibly handle the interrupt (if needed). > > > > +This can be seen as an alternative to shared interrupts when at least one > > > > +of the interrupt children is a timer (and require the irq to stay enabled > > > > +on suspend) while others are not. This will prevent calling irq handlers of > > > > +non timer devices while they are suspended. > > > > > > This sounds like a DT-workaround for a Linux implementation problem, and > > > I don't think this the right way to solve your problem. > > > > I understand your concern, but why are you answering while I asked for > > DT maintainers reviews for several days (if not several weeks). > > I am sorry that I did not spot those, and I am very sorry that this > means I am only now able to air my concerns. > > > > Why does this have to be in DT at all? Why can we not fix the core to > > > handle these details? > > > > We already discussed that with Rob and Thomas, and hiding such a > > demuxer chip is not an easy task. > > I'm open to any suggestion to do that, though I'd like you (I mean DT > > guys) to provide a working implementation (or at least a viable concept) > > that would silently demultiplex an irq. > > Is it truly necessary to drop a emux in the middle? > > As far as I can see, all that we're attempting to do here is hide the > IRQF_NO_SUSPEND mismatch from the core IRQ code, though I've only just > started digging and haven't yet figured out where/why the core code > cares. Any hints? You should have a look at this thread [1] ;-) [1]https://lkml.org/lkml/2014/12/15/552 -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
