use_10_for_ms revisited?

[Jeff Garzik <jgarzik@pobox.com>]

I was reading the specs just now, and I see that the inquiry page 
defines how ATAPI and USB devices indicate they are compliant with MMC-4.

And, MMC-4 does not define read/write/modesen/modesel 6-byte commands at 
all.

My conclusion is that we should notice up front when MMC-4 is supported, 
and simply adhere to the spec by always sending 10-byte commands for 
that device.  I do not think that translation of 6-to-10 byte commands 
is answer, which is what happens now.  Our SCSI layer (sr.c, etc.) 
should, IMO, be compliant with MMC-4 and simply send the right commands.

This also implies that use_10_for_ms simply need not exist -- "first try 
10 byte commands for this device" is false...  for some devices we 
should be unconditionally sending 10 byte commands, no ifs, ands, or buts :)

I'll see if I can work up a patch, if noone objects...

	Jeff, debugging atapi support in his ata-scsi driver