> Using the initial GTM value is the right thing to do because both are
> trying to check firmware setting and by the time ->cable_detect runs
> the controller is already forced into PIO0 by reset.
As we only look at the DMA bits that doesn't matter but I agree it would
be cleaner if we were more careful. Also our mode setting outside
pata_acpi doesn't touch the ACPI settings so its ok for that reason too.
> + * Determine cable type from UDMA configuration in @gtm. If UDMA is
> + * disabled, it returns ATA_CBL_PATA_UNK. If UDMA is enabled and
> + * faster than 33, PATA_80; otherwise, PATA_40.
NAK
Consider the case of a UDMA 33 capable device on an 80 wire cable. We
simply can't use the cable detect methods to prove it is 40 wire this way.
What we actually know is
If UDMA > 33 selected -> UDMA > 33 works
80 wire
Short
or SATA
If UDMA > 33 not selected Unknown
40 wire
80 + Drive limit
80 + Controller limit
80 + BIOS is set to PIO
etc
The only case I can see you could reasonably suggest 40 wire would be
IFF the drive is capable of UDMA > 33 _and_ the ACPI mode is UDMA 33.
Alan
-
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
