I ran into an odd problem yesterday. A customer wanted me to set up a
parallel port fingerprint scanner on a new system. I've got a working
driver for the scanner, confirmed working on a SuSE 2.2.14 setup at this
site. Since the target machine was not quite ready, we replaced the
hard drive.
The new system was to use a TurboLinux distro, also 2.2.14. I did the
install, added the modules, and found that the parallel port reads were
all reading zero. I've seen this before during module development,
where the parallel hardware was left in the wrong mode. That bug is
supposedly fixed. With full debugging on I can see that all the
handshakes are taking place, the device is receiving commands correctly,
it is sending the proper number of bytes in responses, it negotiates,
but all the data reads are zero.
We can eliminate hardware variations because with the other hard drive
in this same system everything runs correctly. It is some software
variation. The parallel driver code is the same, but it is recompiled
to use the Turbo provided includes.
Any hints about likely places to check or configuration items that might
disable the read drivers?
R Horn rjh@world.std.com
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This archive was generated by hypermail 2b29 : Fri Sep 29 2000 - 07:26:27 EDT