[Linux-parport] parallel port detection problem on Thinkpad 600E

Igor Antokhin igor at sai.msu.ru
Thu Mar 31 07:49:51 EST 2005

Hi all,

the problem with the laptop is that the parallel port is not working in 
any Linux distribution. I tried Fedora Core 3, FC2, RH9.0, knoppix, 
kernels from 2.4.x , 2.9.x, 2.10.x - no dice. The sympthoms are these:

I set the io address of the parport through ThinkPad Configuration 
Utility (this is the only way to change BIOS setting on this laptop, no 
menus on BIOS pages) in windows XP, irq=none, disable ECP/EPP modes 
for simplicity, CHECK THAT THE PORT IS WORKING IN WINDOWS, reboot to 
Linux, dmesg says:

lp: driver is loaded but no devices found.

OK, I rmmod lp, parport_pc, parport, and load parport_pc manually 
providing the io address and irq as parameters, e.g.

modprobe parport_pc io=0x378, irq=none

I also have the line

alias parport_lowlevel parport_pc

in /etc/modprobe.conf as recommended in several places.

after that, dmesg says

parport 0x378 (WARNING): CTR: wrote 0x0c, read 0xff
parport 0x378 (WARNING): DATA: wrote 0xaa, read 0xff
parport 0x378: You gave this address, but there is probably no parallel port 
parport0: PC-style at 0x378 [PCSPP,TRISTATE]

Again, the combination io=0x378 and irq=none was set in windows and was
working there. I tried io = 0x278, 0x3bc, different irqs, set ECP/EPP 
modes (of course first setting these parameters in windows, checking, 
then using the same pars in Linux) - nothing helps...

Also disabled dma in Linux adding the option dma=none to the modprobe 
command - same result.

There is a bug with the similar results described on a RedHat page

but it seems it is a different bug as it shows a specific call trace 
during the system boot, which does not happen in my case.

This is a real pity as the only reason for buying this old laptop was 
that my son was going to use it under Linux to program microcontrollers 
through the parallel port...

Any help would be greatly appreciated. The current linux distribution on 
the laptop is FC3 with its native kernel.


PS: Sorry I am not a registered user of this mailing list. I shall 
check it or please send a direct message to igor at sai.msu.ru.

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