Hi Peter,

quoted

I still didn't understand why can't this just be taken care of in your
I2C host driver? Why can't you just read 4 bytes at a time in your
master_xfer hook until you have received as much as the message is
asking, and only after that return?

The I2C host hardware *cannot* read more than 4 bytes in any one xfer
according to the HW designers. Seriously broken crap, that piece of
hardware... (If that assertion from the HW designers is indeed true?
I suspect that it can be made to work, but the docs are closed and I
don't have HW to experiment with, so it remains a suspicion...)

And the I2C host driver *cannot* be expected to know exactly how any
one client device needs to split xfers into many when the 4 byte limit
is getting in the way, and neither can the I2C core. Because I bet
there are devices where it's not even possible to split xfers while
keeping semantics equivalent...

So, every client driver will need to adjust to this quirk if they are
to operate with this worthless I2C host (or others with similar
limitations, if there are any?). Fortunately, most client drivers don't
read in bulk. Unfortunately, many do...

OK, thanks for the explanation.

I think I'm repeating these questions. You guys already went through
this, so sorry for the noise.


Thanks,