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Date: Wed, 21 Feb 2018 04:49:38 +0100
From: Andrew Lunn <andrew@lunn.ch>
To: Arnd Bergmann <arnd@arndb.de>
Cc: arm@kernel.org, Jason Cooper <jason@lakedaemon.net>,
        Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
        Gregory Clement <gregory.clement@free-electrons.com>,
        Russell King <linux@armlinux.org.uk>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Florian Fainelli <f.fainelli@gmail.com>
Subject: Re: [PATCH 2/3] ARM: orion: mark orion_ge00_mvmdio_bus_name as const
Message-ID: <20180221034938.GE14844@lunn.ch>
References: <20180220162519.1498223-1-arnd@arndb.de>
 <20180220162519.1498223-2-arnd@arndb.de>
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On Tue, Feb 20, 2018 at 05:24:51PM +0100, Arnd Bergmann wrote:
> A section type mismatch warning shows up when building with LTO,
> since orion_ge00_mvmdio_bus_name was put in __initconst but not marked
> const itself:
> 
> include/linux/of.h: In function 'spear_setup_of_timer':
> arch/arm/mach-spear/time.c:207:34: error: 'timer_of_match' causes a section type conflict with 'orion_ge00_mvmdio_bus_name'
>  static const struct of_device_id timer_of_match[] __initconst = {
>                                   ^
> arch/arm/plat-orion/common.c:475:32: note: 'orion_ge00_mvmdio_bus_name' was declared here
>  static __initconst const char *orion_ge00_mvmdio_bus_name = "orion-mii";
>
> This marks it const as well.

Hi Arnd

I'm not sure this is the correct fix. orion_ge00_mvmdio_bus_name is
assigned to orion_ge00_switch_board_info->bus_id. This is then passed
to mdiobus_register_board_info() which makes a copy of
orion_ge00_switch_board_info and adds it to its linked list. The
original orion_ge00_switch_board_info will get freed since it is
__initdata, but the copy still has a pointer to
orion_ge00_mvmdio_bus_name, which also gets freed.

I think the correct fix is to remove the __initconst from
orion_ge00_mvmdio_bus_name. Marking it const is however valid.

	Andrew