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Subject: Re: [PATCH] sh: avoid using IRQ0 on SH3/4
From:   Sergey Shtylyov <s.shtylyov@omp.ru>
To:     Rich Felker <dalias@libc.org>, <linux-sh@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
CC:     Yoshinori Sato <ysato@users.sourceforge.jp>
References: <2f419ed2-66b8-4098-7cd3-0fe698d341c9@omp.ru>
Organization: Open Mobile Platform
Message-ID: <63f06bf0-fc7b-3c5c-8af9-5adfd7628354@omp.ru>
Date:   Fri, 11 Feb 2022 23:28:55 +0300
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On 2/11/22 11:15 PM, Sergey Shtylyov wrote:

> Using IRQ0 by the platform devices is going to be disallowed soon (see [1])
> and the code supporting SH3/4 SoCs maps the IRQ #s starting at 0 -- modify
> that code to start the IRQ #s from 16 instead.
> 
> [1] https://lore.kernel.org/all/5e001ec1-d3f1-bcb8-7f30-a6301fd9930c@omp.ru/
> 
> Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
> 
> ---
> The patch is against Linus Torvalds' 'linux.git' repo.
> 
>  arch/sh/kernel/cpu/sh3/entry.S |    4 ++--
>  include/linux/sh_intc.h        |    6 +++---
>  2 files changed, 5 insertions(+), 5 deletions(-)
> 
> Index: linux/arch/sh/kernel/cpu/sh3/entry.S
> ===================================================================
> --- linux.orig/arch/sh/kernel/cpu/sh3/entry.S
> +++ linux/arch/sh/kernel/cpu/sh3/entry.S
> @@ -470,9 +470,9 @@ ENTRY(handle_interrupt)
>  	mov	r4, r0		! save vector->jmp table offset for later
>  
>  	shlr2	r4		! vector to IRQ# conversion
> -	add	#-0x10, r4
>  
> -	cmp/pz	r4		! is it a valid IRQ?
> +	mov	#0x10, r5
> +	cmp/ge	r5, r4		! is it a valid IRQ?

   Maybe I should've used cmp/hs... my 1st try at SH assembly! :-)

[...]

MBR, Sergey