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SubjectRe: [PATCH] M68k IDE updates
On Mon, 14 Apr 2003, Linus Torvalds wrote:
> On Mon, 14 Apr 2003, Paul Mackerras wrote:
> > Since __ide_mm_insw doesn't get told whether it is transferring normal
> > sector data or drive ID data, it can't necessarily do the right thing
> > in both situations.
>
> Can we please then just separate the two functions out into "fetch sector
> data" and "fetch drive ID"? And NOT playing with another frigging broken
> passed-down flag that people get wrong and isn't obvious what it does
> anyway? It's a lot easier to do
>
> /* On sane architectures, data and ID are accessed the same */
> #define ide_fetch_sector_data(...) __ide_fetch_data(..)
> #define ide_fetch_id_data(...) __ide_fetch_data(..)
>
> than it is to carry a flag around and having to remember to get it right
> in every place this is used.

OK, I took a closer look at the IDE identification innards.

It's quite easy to call hwif->ata_input_id() instead of hwif->ata_input_data()
for reading the drive ID. Then hwif->ata_input_id() can take care of the
byteswapping for hardwired byteswapped IDE busses.

However, there's also a routine that involves more magic:
taskfile_lib_get_identify(). While trying to understand that one, I found more
commands that should call the (possible byteswapping) hwif->ata_input_id()
operations, like SMART commands. So first we need a clearer differentiation
between commands that transfer on-platter data, or other drive data.

Any comments from the IDE experts?

Gr{oetje,eeting}s,
Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds


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