Re: [PATCH] ath9k: fix calibration data endianness

[Andrew Lunn]

> |       if (ah->eep_ops->get_eepmisc(ah) & AR5416_EEPMISC_BIG_ENDIAN) {
> |               *swap_needed = true;
> |               ath_dbg(common, EEPROM,
> |                       "Big Endian EEPROM detected according to EEPMISC register.\n");
> |       } else {
> |               *swap_needed = false;
> |       }
> 
> This doesn't take into consideration that swapping is not needed if
> the data is in big endian format on a big endian device. So, this
> could be changed so that the *swap_needed is only true if the flag and
> device endiannes disagrees?

There are versions of the macro which performs the swap which
understands the CPU endianness and become a NOP when it is not
required. htons()/ntohs() are the classic examples. So you need to
consider:

Despite swap_needed being true, it is possible no swap it actually
happening, because such a macro is being used.

and

Maybe using these variant can make the code simpler, by just doing the
NOP swap when the CPU endianess does not require it.

    Andrew