> Okay. But what is missing in the driver because of which it should
> mask out I2C_FUNC_SMBUS_QUICK.

From the spec:

The case when ``length of \field{write_buf}''=0, and at the same time,
``length of \field{read_buf}''=0 doesn't make any sense.

I mentioned this in my first reply and to my understanding I did not get
a reply that this has changed meanwhile.