PPP feature request (Tx queue len + close)

[Jean Tourrilhes <jt@bougret.hpl.hp.com>]

	Hi,

	While working with IrNET, I came across one problems that
would require some changes minor to the ppp_generic kernel code. I
will describe this feature and then we can start to flame each other
or discuss how to implement them.

	IrNET is PPP over an IrDA socket. A good analogy would be PPP
over TCP/IP. If you thing in those terms, you will get the proper
context. IrNET is a PPP driver hooking directly in ppp_generic.

Tx queue length
---------------
	Problem : IrDA does its buffering (IrTTP is a sliding window
protocol). PPP does its buffering (1 packet in ppp_generic +
dev->tx_queue_len = 3). End result : a large number of packets queued
for transmissions, which result in some network performance issues.

	Solution : could we allow the PPP channel to overwrite
dev->tx_queue_len ?
	This is similar to the channel beeing able to set the MTUs and
other parameters...

	Have fun...

	Jean