[3315] in linux-scsi channel archive
Warning low DMA Buffers
daemon@ATHENA.MIT.EDU (flavio santos)
Fri Feb 13 11:21:40 1998
Date: Fri, 13 Feb 1998 11:50:28 -0300
From: flavio santos <flavio@dtpdf.gov.br>
Reply-To: flavio@dtpdf.gov.br
To: eric@andante.jic.com
CC: linux-scsi@vger.rutgers.edu
Using AHA 1542CF with a SCSI-CD Sony and having the Warning message
"Running low on DMA buffers". The message is just a warninng, the CD is
working. The computaer has 32 Mb RAM. The free command show tha buffers
going almost to ZERO.
Mr. Eric Youngdale (eric@andante.jic.com) gave me a helpful orientation
telling to check out the source code in sd.c and sr.c and locate the
line of code that matches the message. I have still some questions ...
I have examined the sd.c and sr.c files. I've examined the amount of
free buffers while running the scsi CD. For sure I can manage the
source code to avoid that message (at least it gives me a braek :/ ),
but the resources are still slow. I'm using the AHA1542 criver (not
1542CF) as a module, and I've compiled it using kernell 3.0.33 (3.0.30
or 32 makes no difference in this case).
An interesting point: after a fresh install of RedHat or Slackware, the
SCSI works well without that warning message. Probably fresh
installation uses another drive such as standard SCSI.
Shouldn't the AHA1542 driver manage to negotiate the traffic betwen the
AHA board and the buffers?
