Re: [gphoto-kodak] Re: Kodak DC-265 overrunning linux serial driver?

brian@worldcontrol.com
Sat, 20 Nov 1999 02:05:32 -0800


On Fri, Nov 19, 1999 at 06:35:07PM +0000, Jim Thompson wrote:
> Ted, I get the same buffer overrun on two modern systems: a brand-new
> Dell I3700 laptop, and a SCSI-only P2B-S motherboard. Furthermore, the
> problem will occur when there is relatively little disk activity. On
> the other hand, the error is much more frequent when there's significant
> CPU load.
>
> What about Brian's note about the overruns not occurring when he's
> running a 2.3 kernel? Is there any significant difference between the
> 2.2 and 2.3 serial drivers that would account for this?

The problem will occur when there is no disk activity. One,
I took out all the writes to the local filesystem. Two, I
ran it on a remote fs.

Bottom line, on my laptop 115200 dies right away all the time.

On the other hand, downloading pictures at 115200 on my laptop
works fine in single user mode.

So someone or something does seem to be holding of the servicing
of the serial interrupt in multi-user mode.

Oh, I also, while in multi-user mode, downloaded or attempted to
download pictures at various rates while a netscape was in
an infinite loop trying to hog 100% of the CPU time. This did
not affect the behavior of the downloads. 115200 died all the
time right away. 57600 worked most of the time.

On the other hand, sort of general work (like moving among desktops
in WindowMaker and running mutt and using vi) would cause 57600
downloading to abort regularly.

-- 
Brian Litzinger <brian@litzinger.com>

Copyright (c) 1999 By Brian Litzinger, All Rights Reserved

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