From: Boris Brezillon <boris.brezillon@free-electrons.com>
To: Mark Rutland <mark.rutland@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Jason Cooper <jason@lakedaemon.net>,
Nicolas Ferre <nicolas.ferre@atmel.com>,
Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>,
Alexandre Belloni <alexandre.belloni@free-electrons.com>,
Rob Herring <robh+dt@kernel.org>, Pawel Moll <Pawel.Moll@arm.com>,
Ian Campbell <ijc+devicetree@hellion.org.uk>,
Kumar Gala <galak@codeaurora.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v4 3/5] irqchip: Add DT binding doc for the virtual irq demuxer chip
Date: Tue, 10 Feb 2015 16:52:01 +0100 [thread overview]
Message-ID: <20150210165201.634bc04b@bbrezillon> (raw)
In-Reply-To: <20150210153628.GF9432@leverpostej>
Hi Mark,
On Tue, 10 Feb 2015 15:36:28 +0000
Mark Rutland <mark.rutland@arm.com> 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@free-electrons.com>
> > Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
> > ---
> > .../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).
>
> 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.
>
> I am very much not keen on this binding.
Yes, but do you have anything else to propose.
We're experiencing this warning for 2 releases now, and this is time to
find a solution (even if it's not a perfect one).
>
> > +
> > +Required properties:
> > +- compatible: Should be "virtual,irq-demux".
> > +- interrupt-controller: Identifies the node as an interrupt controller.
> > +- interrupts-extended or interrupt-parent and interrupts: Reference the source
> > + interrupt connected to this dumb demuxer.
> > +- #interrupt-cells: The number of cells to define the interrupts (should be 1).
> > + The only cell is the IRQ number.
> > +- irqs: u32 bitfield specifying the interrupts provided by the demuxer.
>
> Arbitrary limitation?
I first proposed to make this field unlimited, but Thomas suggested to
keep it limited to 32 bits (and I didn't complain since my HW needs
far less than 32 interrupts).
Best Regards,
Boris
--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
next prev parent reply other threads:[~2015-02-10 15:52 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-29 10:33 [PATCH v4 0/5] ARM: at91: fix irq_pm_install_action WARNING Boris Brezillon
2015-01-29 10:33 ` [PATCH v4 1/5] genirq: Authorize chained handlers to remain disabled when initialized Boris Brezillon
2015-01-29 10:33 ` [PATCH v4 2/5] irqchip: add virtual demultiplexer implementation Boris Brezillon
2015-02-10 15:00 ` Peter Zijlstra
2015-02-10 15:20 ` Boris Brezillon
2015-02-10 15:43 ` [PATCH] genirq: fix virtual irq demuxer related comments Boris Brezillon
2015-02-10 16:14 ` Peter Zijlstra
2015-02-20 16:12 ` Mark Rutland
2015-02-20 16:17 ` Peter Zijlstra
2015-02-10 15:48 ` [PATCH v4 2/5] irqchip: add virtual demultiplexer implementation Mark Rutland
2015-01-29 10:33 ` [PATCH v4 3/5] irqchip: Add DT binding doc for the virtual irq demuxer chip Boris Brezillon
2015-02-10 15:36 ` Mark Rutland
2015-02-10 15:52 ` Boris Brezillon [this message]
2015-02-10 16:06 ` Boris Brezillon
2015-02-10 16:16 ` Mark Rutland
2015-02-10 16:20 ` Boris Brezillon
2015-02-10 20:48 ` Mark Rutland
2015-02-11 8:53 ` Boris Brezillon
2015-02-11 11:11 ` Mark Rutland
2015-02-11 12:24 ` Boris Brezillon
2015-02-11 12:36 ` Mark Rutland
2015-02-11 13:38 ` Alexandre Belloni
2015-02-11 13:48 ` Mark Rutland
2015-02-11 14:55 ` Rafael J. Wysocki
2015-02-11 14:43 ` Mark Rutland
2015-02-11 15:17 ` Rafael J. Wysocki
2015-02-11 15:03 ` Boris Brezillon
2015-02-11 15:39 ` Rafael J. Wysocki
2015-02-11 15:23 ` Mark Rutland
2015-02-11 15:12 ` Mark Rutland
2015-02-11 15:51 ` Rafael J. Wysocki
2015-02-11 15:57 ` Mark Rutland
2015-02-11 16:15 ` Boris Brezillon
2015-02-11 16:32 ` Mark Rutland
2015-02-11 16:38 ` Boris Brezillon
2015-02-11 17:17 ` Mark Rutland
2015-02-20 14:22 ` Mark Rutland
2015-02-20 14:53 ` Boris Brezillon
2015-02-20 15:16 ` Mark Rutland
2015-02-23 17:00 ` Boris Brezillon
2015-02-23 18:14 ` Mark Rutland
2015-02-23 20:16 ` Boris Brezillon
2015-02-11 16:42 ` Rafael J. Wysocki
2015-02-11 16:28 ` Boris Brezillon
2015-02-11 17:13 ` Mark Rutland
2015-02-11 17:29 ` Boris Brezillon
2015-02-12 10:52 ` Mark Rutland
2015-02-12 11:09 ` Boris Brezillon
2015-02-12 11:23 ` Mark Rutland
2015-02-16 9:49 ` Peter Zijlstra
2015-02-16 9:28 ` Peter Zijlstra
2015-02-16 12:23 ` Mark Rutland
2015-02-19 1:16 ` Rafael J. Wysocki
2015-02-19 11:23 ` Mark Rutland
2015-02-19 22:35 ` Rafael J. Wysocki
2015-02-20 10:31 ` Mark Rutland
2015-02-24 1:02 ` Rafael J. Wysocki
2015-02-24 8:42 ` Boris Brezillon
2015-02-11 14:45 ` Boris Brezillon
2015-02-11 14:39 ` Rafael J. Wysocki
2015-02-11 9:11 ` Peter Zijlstra
2015-02-11 11:15 ` Mark Rutland
2015-02-11 14:31 ` Rafael J. Wysocki
2015-02-11 14:14 ` Mark Rutland
2015-02-11 15:07 ` Rafael J. Wysocki
2015-02-11 15:03 ` Mark Rutland
2015-02-11 14:34 ` Rafael J. Wysocki
2015-01-29 10:33 ` [PATCH v4 4/5] ARM: at91/dt: select VIRT_IRQ_DEMUX for all at91 SoCs Boris Brezillon
2015-01-29 10:33 ` [PATCH v4 5/5] ARM: at91/dt: define a virtual irq demultiplexer chip connected on irq1 Boris Brezillon
2015-02-09 15:47 ` [PATCH v4 0/5] ARM: at91: fix irq_pm_install_action WARNING Boris Brezillon
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