> On the other hand, you're still not answering my question about
> why the low level driver(s) would care about that state.  They
> have one job:  "respond to requests from upper levels".  It's
> the upper levels who are responsible for ensuring that only
> valid requests get passed down.  (Leaving no reason for the low
> level code to care about TAP states.

It has nothing to do with valid or invalid requests as such.

Today, in the driver model, the lower level drivers know what
the TAP state is as each request has the end state passsed down.

This can be used in hardware acceleration to queue both e.g.
clocking out of bits *and* navigating to the end state in a single
operation.

After a tms sequence, the upper levels have to tell the lower level
driver what state it is in after that tms sequence. With the
change, the add tms sequence is now identical to all the
other interface_ fn's in that regard.



-- 
Øyvind Harboe

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