[PATCH 1/2] mtd mxc_nand: use 32bit copy functions

Sascha Hauer s.hauer at pengutronix.de
Fri May 25 10:59:01 EDT 2012


On Fri, May 25, 2012 at 05:58:22PM +0300, Artem Bityutskiy wrote:
> On Fri, 2012-05-25 at 16:22 +0200, Sascha Hauer wrote:
> > The following commit changes the function used to copy from/to
> > the hardware buffer to memcpy_[from|to]io. This does not work
> > since the hardware cannot handle the byte accesses used by these
> > functions. Instead of reverting this patch introduce 32bit
> > correspondents of these functions.
> 
> Could you please take a look at the checkpatch.pl updates?

Will do.

> 
> WARNING:LONG_LINE: line over 80 characters
> #103: FILE: drivers/mtd/nand/mxc_nand.c:276:
> +static void memcpy32_fromio(void *trg, const volatile void __iomem  *src, size_t size)
> 
> WARNING:VOLATILE: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt
> #103: FILE: drivers/mtd/nand/mxc_nand.c:276:
> +static void memcpy32_fromio(void *trg, const volatile void __iomem  *src, size_t size)

This makes me wonder a bit, I basically copied the prototype from
the _memcpy_*_io template from arch/arm/kernel/io.c. Should they
be wrong?
otoh I also wondered why there were volatiles in arch/arm/kernel/io.c
in the first place ;)

Sascha

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