Subject: Re: com rumblings...
To: Garrett D'Amore <>
From: Charles M. Hannum <mycroft@MIT.EDU>
List: tech-kern
Date: 06/15/2006 16:07:55
On Thu, Jun 15, 2006 at 12:54:53PM -0700, Garrett D'Amore wrote:
> There is a ring buffer in the middle that is used to transfer between
> the hard and soft interrupts, but if the soft interrupt doesn't get
> timely enough service, then even that will fill up.

It certainly will.  And that's better than dropping random intermittent
bytes in the hardware interrupt handler -- because in that case you get
livelock with PPP and SLIP.

Which is to say, you haven't understood the purpose of the flow control
architecture in the driver, so please don't mess with it.

As for zs vs. com, notice that their guts are almost identical.  Maybe
this is because I retooled both of them at the same time...