Re: [IDE] meaningless #ifndef?

[Andrzej Krzysztofowicz <ankry@pg.gda.pl>]

"Pozsar Balazs wrote:"
> from drivers/ide/ide-features.c:
> 
> /*
>  *  All hosts that use the 80c ribbon mus use!
>  */
> byte eighty_ninty_three (ide_drive_t *drive)
> {
>         return ((byte) ((HWIF(drive)->udma_four) &&
> #ifndef CONFIG_IDEDMA_IVB
>                         (drive->id->hw_config & 0x4000) &&
> #endif /* CONFIG_IDEDMA_IVB */
>                         (drive->id->hw_config & 0x6000)) ? 1 : 0);
> }
> 
> If i see well, then this is always same whether CONFIG_IDEDMA_IVB is
> defined or not.

No, it is not the same. But it duplicates the test when CONFIG_IDEDMA_IVB
is not set. If both tests are done and the first is true, the second also
must be true. If the first is false, the second is meaningless.
Maybe the above code should be:

        return ((byte) ((HWIF(drive)->udma_four) &&
#ifndef CONFIG_IDEDMA_IVB
                        (drive->id->hw_config & 0x4000)
#else
                        (drive->id->hw_config & 0x6000)
#endif /* CONFIG_IDEDMA_IVB */
			) ? 1 : 0);

Just my 0.03 PLN... 
--
=======================================================================
  Andrzej M. Krzysztofowicz               ankry@mif.pg.gda.pl
  phone (48)(58) 347 14 61
Faculty of Applied Phys. & Math.,   Technical University of Gdansk