Re: use_10_for_ms revisited?

[Jeff Garzik <jgarzik@pobox.com>]

Matthew Dharm wrote:
> I'm somewhat concerned that, just as we're finding something that works,
> we're going to go off in another direction.
> 
> I certainly wouldn't mind removing the code that manipulates the SCSI
> revision number.

I'm talking about code in the scsi core that does stuff like ("if 
scsi_level <= 2" ...), which is wrong for MMC, where version==0 is a 
valid value on modern atapi and usb devices.


> But, the 6-to-10 conversion code (at least for USB) is all about to go
> away, once we settle on how sr.c (and friends) should handle use_10_for_ms
> -- so one of your reasons to change all this is already moot.

Not really, see below.


> I guess, in part, I'm hesitant to rely on fields in the INQUIRY data that
> nobody has checked to verify that they are actually useful.  Most USB
> devices are made on ultra-low testing, and commonly have bad bits in any
> field that isn't used by Windows or MacOS.

MMC-4 is the culmination of the stuff that's in the field now.

Really, sr wants to know "are you mmc-compliant?"

If the answer is yes, it should only use MMC-defined commands (mode 
sense 10, etc.).

use_10_for_ms is a subset of that.

	Jeff