LPT port in RHEL 5

**Sun-Kem** · 09-28-2011

Hi everyone,
Please help me the way to check LPT port in RHEL 5.
I want to install printer through LPT port, but when install, I can not see LPT port in Printer configuration.
Thanks a lot.

***Roxoff*** · 09-28-2011

The Printer Port isn't disabled in the machine's BIOS settings is it? On every computer I've set up for the last five or more years I've gone into the BIOS and disabled and parallel and serial ports - they're hardly ever needed these days.

**atreyu** · 09-28-2011

Is the parallel port kernel driver already loaded? Check with:

Code:

lsmod|grep parp

You should see possibly parport, parport_pc and lp.

If not, try loading it:

Code:

modprobe parport

Make sure they're not blacklisted (prevented from loading):

Code:

grep ^blacklist\ parp /etc/modprobe.d/blacklist

Note: the location of your blacklist might be different.

Make sure the driver has not been disabled at boot-time:

Code:

cat /proc/cmdline|grep parport

See if the parallel port has acquired an IRQ:

Code:

cat /proc/interrupts |grep parp

**Sun-Kem** · 10-05-2011

Thanks atreyu and Roxoff very much.
- Printer port is enable in BIOS setting
the parallel port kernel driver already loaded? Check with:
Code:

Code:

lsmod|grep parp => parport 37513 1 lp

You should see possibly parport, parport_pc and lp.

If not, try loading it:
Code:

modprobe parport

Make sure they're not blacklisted (prevented from loading):
Code:

Code:

grep ^blacklist\ parp /etc/modprobe.d/blacklist.conf => nothing

Note: the location of your blacklist might be different.

Make sure the driver has not been disabled at boot-time:
Code:

Code:

cat /proc/cmdline|grep parport => nothing

See if the parallel port has acquired an IRQ:
Code:

Code:

cat /proc/interrupts |grep parp => nothing

Is there anything else I should try?
One more thing, in printer configuration, I do not see usb port, too, although my computer has 3 usb ports.

**atreyu** · 10-05-2011

Hmmm...so the parport kernel driver loaded and what's more the lp driver is using it. But what about parport_pc? Maybe it needs to be loaded (I have no idea), try:

Code:

modprobe parport_pc

I don't know much about parallel ports, but it seems not good that the parallel port is not getting assigned an IRQ. On my machine w/a parallel port, it is getting an IRQ anyway.

Also, run this to get kernel messages relateted to the parallel port:

Code:

dmesg|egrep -i 'paral|parp'

Do you have the proper char device available?

Code:

ls -l /dev/parport0

**Sun-Kem** · 10-07-2011

Thanks for your quick reply, atreyu.

Here are the results when I try your suggestion:
Code:

Code:

modprobe parport_pc
=> FATAL: Error inserting parport_pc (/lib/modules/2/6/18-238.el5/kernel/drivers/parport/parport_pc.ko): Invalid argument

Code:

dmesg|egrep -i 'paral|parp'
=> (appear 4 lines below)
parport_pc: '0x378' invalid for parameter 'io'

the proper char device available?

Code:

Code:

ls -l /dev/parport0
=> crw-rw---- 1 root lp 99 0 Oct 7 09:53 /dev/parport0

**atreyu** · 10-07-2011

I'm not sure what to make of those parport_pc errors. Maybe you have a wacky parallel port that wants to use a different base address? Is the address of the parallel port settable in the BIOS? If it isn't 0x378, try changing it to it.

Also, in any event, reboot and then run the dmesg|egrep -i 'paral|parp' command again.

**Sun-Kem** · 10-11-2011

The old address of parallel port is 0x278, I changed to 0x378, but got the same results.
How I change default address 0x378 for parport to 0x278 (default address in bios setting)?

**atreyu** · 10-11-2011

Check out the kernel parameters listed here. Search for parport= to see the parameters you can pass to the kernel at boot time.

Thread Tools

Display

LPT port in RHEL 5

Posting Permissions