Bjørn Mork bjorn at mork.no
Tue Mar 1 14:05:39 UTC 2016

nietzsche at lysator.liu.se writes:

> OK, this is the pcap dump of the start and connect sequence on Windows 10
> with Telenor SE.

Thanks!  Educating stuff.  A quick analysis:

The Windows driver sends a "reset function" request after the "get NTB
parameters" request.  The Linux driver doesn't do that.  Might make a
difference.  And it sends another "reset function" request just when
you'd think the setup was complete, restarting it all.  Don't know why
it does that.  Makes no sense to me.  But we could try it just for

The Windows driver sets a sane NTB input size as well, just like Linux.
Unfortunately it seems all request data is missing in this dump?  But
the response size is 32768, so that must be what was requested. Not too
far away from our default (16384).  But we could try the exact same
value to elimininate this unnecessary difference.

The Windows driver requests 32bit mode, even with the reduced buffers.
We cannot do that without adding a bit of code to the driver.  But it is
worth trying as a last resort if we cannot get this to work in 16bit

The Windows driver issues "set NTB input size" before "set NTB format".
We should definitely try that.  Trying to set 16bit format while the
input size is > 2^16 might be considered invalid by the firmware. An
error response would bave been nice, but experience has taught us that
we cannot expect that.  Silent failures seems to be the rule here...


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