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Date:   Thu, 27 Aug 2020 18:24:28 +0300
From:   Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
To:     Marc Zyngier <maz@kernel.org>
Cc:     Rob Herring <robh@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Jason Cooper <jason@lakedaemon.net>,
        Andreas =?iso-8859-1?Q?F=E4rber?= <afaerber@suse.de>,
        Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
        linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
        "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" 
        <linux-arm-kernel@lists.infradead.org>,
        linux-actions@lists.infradead.org
Subject: Re: [PATCH v5 1/3] dt-bindings: interrupt-controller: Add Actions
 SIRQ controller binding
Message-ID: <20200827152428.GA2467154@BV030612LT>
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Hi Marc,

On Thu, Aug 27, 2020 at 11:35:06AM +0100, Marc Zyngier wrote:
> On 2020-08-27 11:06, Cristian Ciocaltea wrote:
> > On Wed, Aug 26, 2020 at 04:48:38PM -0600, Rob Herring wrote:
> > > On Wed, Aug 26, 2020 at 3:42 PM Cristian Ciocaltea
> > > <cristian.ciocaltea@gmail.com> wrote:
> 
> [...]
> 
> > > Ultimately the GIC trigger type has to be
> > > something. Is it fixed or passed thru? If the latter, just use 0
> > > (IRQ_TYPE_NONE) if the GIC trigger mode is not fixed. Having some sort
> > > of translation of the trigger is pretty common.
> > 
> > Yes, as explained above, the SIRQ controller performs indeed the
> > translation of the incoming signal. So if I understand correctly, your
> > suggestion would be to use the following inside the sirq node:
> > 
> > interrupts = <GIC_SPI 13 IRQ_TYPE_NONE>, /* SIRQ0 */
> >              [...]
> 
> Please don't. If you are describing a GIC interrupt, use a
> trigger that actually exists. Given that you have a 1:1
> mapping between input and output, just encode the output
> trigger that matches the input.

Understood, the only remark here is that internally, the driver will
not use this information and instead will continue to rely on the input
to properly set the trigger type for the output.

The question is if the driver should also emit a warning (or error?)
when the trigger type supplied via DT doesn't match the expected value.

If yes, we should also clarify what the user is supposed to provide in
the controller node: the trigger type before the conversion (the input)
or the one after the conversion (the output). 

>         M.
> -- 
> Jazz is not dead. It just smells funny...

Thanks,
Cristi