[U-Boot] MIPS: Fix GCC-4.2 'discards qualifiers from pointer target type' warnings

[Wolfgang Denk]

Dear Shinya Kuribayashi,

In message <49A0E17B.9090300 at ruby.dti.ne.jp> you wrote:
> Compiling dbau1x00 and gth2 boards with GCC-4.2, you would see new warnings
> like this:
> 
> skuribay at ubuntu:u-boot.git$ ./MAKEALL dbau1000
> Configuring for dbau1x00 board...
> au1x00_eth.c: In function 'au1x00_send':
> au1x00_eth.c:158: warning: passing argument 1 of 'virt_to_phys' discards qualifiers from pointer target type
> au1x00_eth.c: In function 'au1x00_recv':
> au1x00_eth.c:211: warning: passing argument 1 of 'virt_to_phys' discards qualifiers from pointer target type
> au1x00_eth.c: In function 'au1x00_init':
> au1x00_eth.c:252: warning: passing argument 1 of 'virt_to_phys' discards qualifiers from pointer target type
> au1x00_eth.c: In function 'au1x00_recv':
> au1x00_eth.c:211: warning: passing argument 1 of 'virt_to_phys' discards qualifiers from pointer target type
> au1x00_eth.c: In function 'au1x00_init':
> au1x00_eth.c:252: warning: passing argument 1 of 'virt_to_phys' discards qualifiers from pointer target type
> au1x00_eth.c: In function 'au1x00_send':
> au1x00_eth.c:158: warning: passing argument 1 of 'virt_to_phys' discards qualifiers from pointer target type
> 
> We're passing a volatile pointer to a function which is expecting a non-
> volatile pointer.  That's potentially dangerous, so gcc warns about it.
> Confirmed with ELDK 4.2 (GCC 4.2.2) and Sourcey G++ 4.2 (GCC 4.2.3).
> 
> To fix this, we add a volatile attribute to the argument in question.
> The virt_to_phys function in Linux kernel also does the same thing.
> 
> Signed-off-by: Stefan Roese <sr at denx.de>
> Signed-off-by: Shinya Kuribayashi <skuribay at ruby.dti.ne.jp>
> ---
> Sorry for late reply,
> 
> Stefan: I think this is a reasonable fix.  I believe this works for ELDK
> as well, of course.
> 
> Walfgang: Please pick this up directly, thanks in advance.
> 
> 
>  include/asm-mips/io.h |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)

Applied, thanks.

Best regards,

Wolfgang Denk

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