I am happy to see this driver upstream.

Arnd's concern was that the rmnet_data0 network device does not
have the benefit of information about the state of the underlying
IPA hardware in order to be effective in controlling TX flow.
The feared result is over-buffering of TX packets (bufferbloat).
I began working on some simple experiments to see whether (or how
much) his concern was warranted.  But it turned out that completing
these experiments was much more work than had been hoped.

Members of the bufferbloat project *care*, and have tools and testbeds for
exploring these issues. It would be good to establish a relationship with
the vendor, obtain hardware, and other (technical and financial) support, if
possible.

Is there any specific hardware now available (generally or in beta) that
can be obtained by us to take a harder look? A contact at linaro or QCA
willing discuss options?