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In-Reply-To: <20180102110141.1853608-1-arnd@arndb.de>
References: <20180102110141.1853608-1-arnd@arndb.de>
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Tue, 2 Jan 2018 15:23:09 +0100
Message-ID: <CAMuHMdVrb56oxz-UuxXAT5c-97J42f+JJ0EY+G6d2vLucDTu5Q@mail.gmail.com>
Subject: Re: [PATCH] arc: fix iounmap prototype
To: Arnd Bergmann <arnd@arndb.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
        Linux-Arch <linux-arch@vger.kernel.org>,
        Vineet Gupta <vgupta@synopsys.com>,
        arcml <linux-snps-arc@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Sender: linux-kernel-owner@vger.kernel.org

Hi Arnd,

On Tue, Jan 2, 2018 at 12:01 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> The missing 'volatile' keyword on the iounmap argument leads to lots of
> harmless warnings in an allmodconfig build:
>
> sound/pci/echoaudio/echoaudio.c:1879:10: warning: passing argument 1 of 'iounmap' discards 'volatile' qualifier f
> pointer target type [-Wdiscarded-qualifiers]
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  arch/arc/include/asm/io.h | 4 ++--
>  arch/arc/mm/ioremap.c     | 2 +-
>  2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arc/include/asm/io.h b/arch/arc/include/asm/io.h
> index c22b181e8206..2c9b98fabf82 100644
> --- a/arch/arc/include/asm/io.h
> +++ b/arch/arc/include/asm/io.h
> @@ -30,11 +30,11 @@ static inline void __iomem *ioport_map(unsigned long port, unsigned int nr)
>         return (void __iomem *)port;
>  }
>
> -static inline void ioport_unmap(void __iomem *addr)
> +static inline void ioport_unmap(volatile void __iomem *addr)
>  {
>  }
>
> -extern void iounmap(const void __iomem *addr);
> +extern void iounmap(const volatile void __iomem *addr);

Note that include/asm-generic/io.h also lacks the volatiles?

>
>  #define ioremap_nocache(phy, sz)       ioremap(phy, sz)
>  #define ioremap_wc(phy, sz)            ioremap(phy, sz)
> diff --git a/arch/arc/mm/ioremap.c b/arch/arc/mm/ioremap.c
> index 9881bd740ccc..94d0116063a8 100644
> --- a/arch/arc/mm/ioremap.c
> +++ b/arch/arc/mm/ioremap.c
> @@ -95,7 +95,7 @@ void __iomem *ioremap_prot(phys_addr_t paddr, unsigned long size,
>  EXPORT_SYMBOL(ioremap_prot);
>
>
> -void iounmap(const void __iomem *addr)
> +void iounmap(volatile const void __iomem *addr)

const volatile?

>  {
>         /* weird double cast to handle phys_addr_t > 32 bits */
>         if (arc_uncached_addr_space((phys_addr_t)(u32)addr))

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds