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Date: Mon, 14 May 2018 01:23:03 -0700
From: Olof Johansson <olof@lixom.net>
To: Stefan Agner <stefan@agner.ch>
Cc: arm@kernel.org, arnd@arndb.de, linux@armlinux.org.uk,
        ard.biesheuvel@linaro.org, robin.murphy@arm.com,
        nicolas.pitre@linaro.org, marc.zyngier@arm.com,
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        Bernhard.Rosenkranzer@linaro.org, mka@chromium.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] bus: arm-cci: remove unnecessary unreachable()
Message-ID: <20180514082303.abk3rnj45i4i2bqn@localhost>
References: <20180508142726.11646-1-stefan@agner.ch>
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On Tue, May 08, 2018 at 04:27:26PM +0200, Stefan Agner wrote:
> Mixing asm and C code is not recommended in a naked function by
> gcc and leads to an error when using clang:
>   drivers/bus/arm-cci.c:2107:2: error: non-ASM statement in naked
>   function is not supported
>         unreachable();
>         ^
> 
> While the function is marked __naked it actually properly return
> in asm. There is no need for the unreachable() call.
> 
> GCC 7.2 generates identical object files before and after, other
> than (for obvious reasons) the line numbers generated by
> WANT_WARN_ON_SLOWPATH for all the WARN()s appearing later in the
> file.
> 
> Suggested-by: Russell King <linux@arm.linux.org.uk>
> Signed-off-by: Stefan Agner <stefan@agner.ch>
> Acked-by: Nicolas Pitre <nico@linaro.org>
> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
> ---
> Changes in v3:
> - Fix subject and enhance commit message
> Changes in v2:
> - Don't add assembly ASM_UNREACHABLE, just drop unreachable()

Applied to next/drivers for v4.18 merge window now. Thanks!


-Olof