4.3 dropping characters ?

[Chris Torek]

In article <323 at uwmacc.UUCP> edwards at uwmacc.UUCP (mark edwards) writes:
>   We have emulex dmfs. It seems either the first character of a line
>   or the last character of a line get dropped occasionally.

The Emulex DMF emulators (CS11 and CS21 series, I believe) do not
exactly emulate DEC DMFs:  They follow only the manuals.  The 4.3BSD
driver's DMA code expects the word count register to be updated by
bytes, not words, and so becomes confused and drops characters.

A very quick fix is to raise dmf_mindma (I think: check /sys/vaxuba/dmf.c
for the exact name).  If you set this beyond 60, no standard 4.3
kernel will do DMA, since 4.3's CBLOCK is set to 64.  Keith Muller
<muller at sdcsvax> has better fixes.  I am using an entirely different
DMF driver myself.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 1516)
UUCP:	seismo!umcp-cs!chris
CSNet:	chris at umcp-cs		ARPA:	chris at mimsy.umd.edu