On Fri, 23 Sep 2011 19:22:56 +0400
Mikhail Kshevetskiy [off-list ref] wrote:

n_gsm use a simple approach: every writing to fifo correspond exactly
one reading from fifo. There are no problem in this approach until we
read less bytes then we write. As result fifo may owerflow. This
leads to packet loss and very slow responce.

We do need to do something here but your change means a single DLCI
will hog the channel, so I think the while loop needs to be one layer
up.

Alan