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Message-ID: <36f05f50-ff5e-71fb-3afb-475c3ac5a376@physik.fu-berlin.de>
Date:   Wed, 2 Mar 2022 11:10:23 +0100
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Subject: Re: [PATCH] sh: avoid using IRQ0 on SH3/4
Content-Language: en-US
To:     Sergey Shtylyov <s.shtylyov@omp.ru>, 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>
From:   John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
In-Reply-To: <2f419ed2-66b8-4098-7cd3-0fe698d341c9@omp.ru>
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Hello!

On 2/11/22 21:15, 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?
>  	bt	10f
>  
>  	/*
> Index: linux/include/linux/sh_intc.h
> ===================================================================
> --- linux.orig/include/linux/sh_intc.h
> +++ linux/include/linux/sh_intc.h
> @@ -13,9 +13,9 @@
>  /*
>   * Convert back and forth between INTEVT and IRQ values.
>   */
> -#ifdef CONFIG_CPU_HAS_INTEVT
> -#define evt2irq(evt)		(((evt) >> 5) - 16)
> -#define irq2evt(irq)		(((irq) + 16) << 5)
> +#ifdef CONFIG_CPU_HAS_INTEVT	/* Avoid IRQ0 (invalid for platform devices) */
> +#define evt2irq(evt)		((evt) >> 5)
> +#define irq2evt(irq)		((irq) << 5)
>  #else
>  #define evt2irq(evt)		(evt)
>  #define irq2evt(irq)		(irq)

Successfully boot-tested without any issues on my SH-7785LCR on top of fb184c4af9b9.

Tested-By: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>

Thanks,
Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz@debian.org
`. `'   Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
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