Parallel port not recognized after latest update?

[x0054]

I have a Compaq ProLiant 5500 runing testing tree of Debian. After last
update yesterday my parallel port is not recognized any more. During the
update the kernel was updated from 2.4.27-2-686-smp to 2.4.27-3-686-smp.
Also X server was updated and some libs.

During the update the message instructed me to reboot the computer after
update is done. After the update I rebooted with new 2.4.27-3-686-smp
kernel, but my parallel port was not recognized. I did try going back to
the previous working kernel, but now the parallel port isn't recognized
under that kernel as well.

Just to see what happens I also installed 2.6.15-1-686-smp and 2.6.11-1-
686-smp. Both run fine, but do not recognize the parallel port. What
happens now is the LPT1 port outputs 1 (high) on all 8 data pins. It
used to be at address 0x3bc. There is no /dev/lp0 and no mention of LPT
port in the /proc/ioports.

I did try running "modeprob parport" which did not give me any errors.
After that I looked at /proc/modules and parport is listed as such:
parport 32840 0 - Live 0xf8c00000

but the port does not work nonetheless.


I am not sure if this is a bug or just something happen during the
install. I am not sure what to do. Any suggestions would be very
helpful.

Thank you,

- Bogdan

[burnit]

partport kernel module is needed to control the parallel port, but you should also load some other module to get a printer working. I'm not sure, but you should load also the lp module.

However, if you're running cups for printing, this module should be loaded automatically. Can you post the output of lsmod?

[x0054]

It terns out that the lp module would not load after the update.
Everything works after doing "modprob lp"

Thank you for the suggestion,

- Bogdan

[yongluouk]

Can you tell me how to check whether parallel port is loaded in Debian? If not, how to load it step by step? I don't have much knowledge of Linux administration. I want to use parallel port to derive a stepper motor.

Thank you.

It terns out that the lp module would not load after the update.
Everything works after doing "modprob lp"

Thank you for the suggestion,

- Bogdan

[x0054]

Do

cat /proc/ioports

That will show you all the ioports. If you have LPT port properly loaded it should show up as a parport0 [or LPTsomething] in the list.

Then read about using that port here:
http://www.epanorama.net/circuits/parallel_output.html

That page has nice c++ code for linux, I used it to build my own control. You would replace the port offset they use in the code with port offset that you found in /proc/ioports. Default though should work fine on most standard boxes.

PS, do not run the motor directly from the port, I am guessing that's obvious though

Good luck,

- Bogdan