Re: [PATCH] sh: Avoid using IRQ0 on SH3 and SH4

[Sergei Shtylyov]

On 7/12/23 11:12 AM, David Laight wrote:

>> Sent: 09 July 2023 00:13
> ....
>> Looking at arch/sh/boards/mach-r2d/irq.c, there is some IRQ translation going
>> on and maybe that's the part where we need to correct the offset by 16?
> 
> Would it be less problematic to use (say) 16 for IRQ_0
> leaving IRQ_1+ as 1+ ?

   I don't think so.

> At least that would only cause issues for code that needed
> to use IRQ_0.
> 
> (It has to be said that making IRQ 0 invalid seemed wrong
> to me. x86 (IBM PC) gets away with it because IRQ 0 is
> always assigned to platform specific hardware.)

   Not only x86, IIRC.
   Have you seen the commit below?

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ce753ad1549cbe9ccaea4c06a1f5fa47432c8289

   IOW, try arguing with Linus. :-)

> 	David

MBR, Sergey