quoted

Is there a use case for odd lengths? Apart from 1.

There's sfp_cotsworks_fixup_check() that does a 3-byte access :
	
	id->base.phys_id = SFF8024_ID_SFF_8472;
	id->base.phys_ext_id = SFP_PHYS_EXT_ID_SFP;
	id->base.connector = SFF8024_CONNECTOR_LC;
	sfp_write(sfp, false, SFP_PHYS_ID, &id->base, 3);

Ah, fixing those broken cotsworks PHYs.

It may be possible to turn that into 2 2-byte accesses if we write

	id->base.phys_id = SFF8024_ID_SFF_8472;
	id->base.phys_ext_id = SFP_PHYS_EXT_ID_SFP;

and then

	id->base.phys_ext_id = SFP_PHYS_EXT_ID_SFP;
	id->base.connector = SFF8024_CONNECTOR_LC;

Or just don't bother fixing the EEPROM, leave it broken, but use the
corrected values internally.

But let's first figure-out if word-only smbus are really a thing

Some grep foo on /drivers/i2c/busses might answer that.

     Andrew