Re: [PATCH] arc: fix iounmap prototype

[Vineet Gupta]

On 01/02/2018 06:23 AM, Geert Uytterhoeven wrote:
> Hi Arnd,
>
> On Tue, Jan 2, 2018 at 12:01 PM, Arnd Bergmann <arnd@xxxxxxxx> 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@xxxxxxxx>

Arnd, do you agree to Geert's comments - if you are busy I can respin a v2 ?

Thx,
-Vineet

> > ---
> >   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