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

From: Arnd Bergmann
Date: Wed Feb 09 2022 - 10:19:08 EST


On Wed, Feb 9, 2022 at 4:11 PM Sergei Shtylyov
<sergei.shtylyov@xxxxxxxxx> wrote:
>
> On 2/8/22 3:31 PM, Arnd Bergmann 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
>
> Mhm... this commit changes the SH3 code while SH778x are SH4A, no?

This code is shared between both:

arch/sh/kernel/cpu/sh4/Makefile:common-y += $(addprefix
../sh3/, entry.o ex.o)

Arnd