Re: [PATCH 2.6.18-rc4 1/5] ieee1394: sbp2: workaround for write protectbit of Initio firmware

[Jeff Garzik]

Linus Torvalds wrote:
> I don't think there really is _ever_ any reason to use the 10-byte version 
> if the 6-byte version is expected to work. Is there?

Yes, but not really important:  10-byte allows a 16-bit allocation 
length (additional data section), where 6-byte only allows 8-bit.

However, the mode pages the kernel requests from the device are normally 
<= 256 bytes.

In general, your intuition is correct.  use_10_for_foo is largely meant 
for the subclass of "SCSI" devices which often don't bother to implement 
the 6-byte commands, forcing the software driver to emulate 6-byte. 
use_10_for_foo allows the software driver to eliminate that in-kernel 
emulation code.

	Jeff


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