Re: [PATCH 2/3] i2c: sh_mobile: Use platform_get_irq_optional() to get the interrupt

[Arnd Bergmann]

On Mon, Dec 20, 2021 at 12:53 PM Sergei Shtylyov
<sergei.shtylyov@xxxxxxxxx> wrote:
> On 20.12.2021 13:17, Geert Uytterhoeven wrote:
>
> > I might have missed something, but it seems the only user of IRQ 0 on
> > SuperH is smsc911x Ethernet in arch/sh/boards/board-apsh4a3a.c and
> > arch/sh/boards/board-apsh4ad0a.c, which use evt2irq(0x200).
> > These should have been seeing the "0 is an invalid IRQ number"
> > warning splat since it was introduced in commit a85a6c86c25be2d2
> > ("driver core: platform: Clarify that IRQ 0 is invalid"). Or not:
>
>     Warning or no warning, 0 is still returned. :-/
>     My attempt to put an end to this has stuck waiting a review from the IRQ
> people...

I had another look at this after you asked about it on IRC. I don't
know much SH assembly, but I suspect IRQ 0 has not been delivered
since 2009 after 1e1030dccb10 ("sh: nmi_debug support."). On a
related note, CONFIG_INTC_BALANCING was broken in 2be6bb0c79c7
("sh: intc: Split up the INTC code.") by inadvertently removing the Kconfig
symbol.

        Arnd