Hi,
On Sunday 30 March 2008, Geert Uytterhoeven wrote:
> Hi Bart,
>
> On Sun, 30 Mar 2008, Bartlomiej Zolnierkiewicz wrote:
> > * Add ->atapi_{in,out}put_bytes and ->ata_{in,out}put_data methods to
> > falconide and q40ide host drivers (->ata_* methods are implemented on
> > top of ->atapi_* methods so they also do byte-swapping now).
> >
> > * Cleanup atapi_{in,out}put_bytes().
>
> Thanks!
>
> One remaining issue (for which the fix has never been submitted upstream so
> far) with Atari and Q40 is that due to the byteswapped interface, the driveid
> is also byteswapped, so it has to be unswapped again in ide_fix_driveid().
My patch causes unswapping for _all_ data coming from the device so I wonder
whether the ide_fix_driveid() fix is still needed?
[ I now recall some discussion that we shouldn't un-swap fs requests because
of how the things were done in the past fs itself is stored byte-swapped on
the disk - if this is the case I will recast the patch to pass rq to
->ata_*put_data in ide_pio_sector() and check rq->cmd_type == REQ_TYPE_FS
in falconide/q40ide_*put_data() to decide whether to unswap data or not ]
Thanks,
Bart
> Here's a very old and unclean but working patch:
>
> --- a/drivers/ide/ide-iops.c
> +++ b/drivers/ide/ide-iops.c
> @@ -284,6 +284,23 @@ void ide_fix_driveid (struct hd_driveid
> int i;
> u16 *stringcast;
>
> +#ifdef __mc68000__
> + if (!MACH_IS_AMIGA && !MACH_IS_MAC && !MACH_IS_Q40 && !MACH_IS_ATARI)
> + return;
> +
> +#ifdef M68K_IDE_SWAPW
> + if (M68K_IDE_SWAPW) { /* fix bus byteorder first */
> + u_char *p = (u_char *)id;
> + u_char t;
> + for (i = 0; i < 512; i += 2) {
> + t = p[i];
> + p[i] = p[i+1];
> + p[i+1] = t;
> + }
> + }
> +#endif
> +#endif /* __mc68000__ */
> +
> id->config = __le16_to_cpu(id->config);
> id->cyls = __le16_to_cpu(id->cyls);
> id->reserved2 = __le16_to_cpu(id->reserved2);
>
> Note that include/asm-m68k/ide.h has
>
> #define M68K_IDE_SWAPW (MACH_IS_Q40 || MACH_IS_ATARI)
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
>
> 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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