Re: mustek aha1520B problems

aanderson = (
Fri, 2 Jul 1999 20:49:55 -0600 (MDT)

>Douglas Gilbert <> responded:
>Did the bigger buffers improve performance and lessen
>the following problems?

To be honest I didn't see any difference, which is why I think
think there are problems with the driver. The performance wasnt
bad in either case, tho, except for the hangups and crashes, the
latter of which typically occurred on large scans where improvement
might have been more apparent. I was careful to get the buffer logistics
right, altho I am suspicious that it seemed to crash more often with
the large buffers..

>My advansys 5140 (ISA aha1540 clone) slows anything else on the
>same SCSI bus cause my UMAX 1220S doesn't support 'disconnects',
>but the rest of my system goes ok (eg my advansys 940UW with my
>root file system on it).

Thanks.. that is the behavior I expected. I'm glad SANE isn't
supposed to behave the way I have been experiencing.

>Time taken to DMA/block_move data to and from the SCSI device
>and any polling that the aha152x driver does will _not_
>show on a command prefixed with "time ".
I assumed the polling should show up under 'sys', but that there
should still be lots of idle time between scsi commands.
What concerned me more was that it seemed to keep on polling even after
the scan stopped.
>Does 'cat /proc/interrupts' show a reasonable count
>of interrupts on the aha152x driver?
Excellent question, thanks. A scan of 1.2 Mb generated 298 interrupts
for 4500 b/interrupt, which seems reasonable for an 8k FIFO. So
that part seems ok.
>Perhaps you could post that info/patch through to
>the aha152x maintainer who is
>Juergen Fischer <>.
I was reluctant to post the patch until I satisfied myself there wasn't
something wrong with the configuration. The fact that that card had been
removed from the 2.2.10 driver is certainly suspicious, which seems
reinforced by the SANE behavior. He may be just the person to run this
by, tho, so I will do that.

>Interesting SCSI version ...
That is what shows. The revision number is also earlier than that in
sane-mustek man page for what that's worth. >

From Al Anderson
- Anything NOT worth NOT worth doing well! AA

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