Subject: Re: dolphin 4079 PCI comm ports (dual serial, 1 parallel)
To: Wolfgang Rupprecht <>
From: Thor Lancelot Simon <>
List: tech-kern
Date: 04/09/2002 12:09:06
On Mon, Apr 08, 2002 at 11:54:00PM -0700, Wolfgang Rupprecht wrote:
> The next thing on the list to investigate is if I can get the kernel
> to run it as a 16650 and use all 32-bytes worth of FIFO.  I added the
> following option and rebuilt, but the chip still gets identified as a
> 16550.

Actually, by default the 16650 either doubles or quadruples the FIFO
threshold values you set so that it does, in fact, use its entire FIFO
(there are '650 variants with both 32 and 64-byte FIFOs).  You do lose
some degree of control over the threshold, of course.  What it doesn't
do is autoflow when you hit the FIFO threshold; you have to put it in '650
mode for that.

> 	  options		COM16650

I've had trouble with this option with several different 16650 cards,
including with a card that worked with the option in one machine, but
not in another!  Early 16650 parts were evidently quite buggy, but I'm
not sure that explains all the driver problems.

 Thor Lancelot Simon	                            
   But as he knew no bad language, he had called him all the names of common
 objects that he could think of, and had screamed: "You lamp!  You towel!  You
 plate!" and so on.              --Sigmund Freud