RE: [PATCH 1/3] dt-bindings/irq: add binding for NXP INTMUX interrupt multiplexer

[Marc Zyngier]

On 2019-12-18 11:34, Joakim Zhang wrote:
> > -----Original Message-----
> > From: Joakim Zhang <qiangqing.zhang@xxxxxxx>
> > Sent: 2019å12æ18æ 18:22
> > To: Marc Zyngier <maz@xxxxxxxxxx>
> > Cc: tglx@xxxxxxxxxxxxx; jason@xxxxxxxxxxxxxx; robh+dt@xxxxxxxxxx;
> > mark.rutland@xxxxxxx; shawnguo@xxxxxxxxxx; s.hauer@xxxxxxxxxxxxxx; 
> > S.j.
> > Wang <shengjiu.wang@xxxxxxx>; kernel@xxxxxxxxxxxxxx;
> > festevam@xxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>;
> > linux-kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx;
> > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; Andy Duan 
> > <fugang.duan@xxxxxxx>;
> > Aisheng Dong <aisheng.dong@xxxxxxx>
> > Subject: RE: [PATCH 1/3] dt-bindings/irq: add binding for NXP INTMUX 
> > interrupt
> > multiplexer

[...]

> > > What I don't understand is how the interrupt descriptor can 
> > indicate
> > > which channel it is multiplexed on. The driver doesn't makes this
> > > clear either, and I strongly suspect that it was never tested with 
> > more than a
> > single channel...
> >
> > Yes, to be frank, I tested with a signle channel, I will take this 
> > into
> > consideration. Thanks.
> Hi Marc,
>
> I tested channels from 1 to 8, and no issue found.
>
> We register irq handler with irq_set_chained_handler_and_data(), so
> the interrupt descriptor could find the controller's private data, 
> and
> channel index is one part of private data.
> I think this can explain the interrupt descriptor how to indicate
> which channel it is multiplexed.

But that doesn't explain how the driver can find which channel a given
interrupts is wired to. Nothing in your binding shows how you can 
extract
the channel number from the interrupt descriptor. Nothing in the driver
even *computes* a channel number.

As far as I can see, you register a bunch of domains, all with the same
OF node, so all your interrupts end-up with the same domain. Is it 
really
what you expect?

This driver looks terribly wrong.

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