[Linux-parport] Re: RFC: add udev support to parport_pc

Jason Dravet dravet at hotmail.com
Sat Dec 31 13:07:47 EST 2005

Thank you for the reply.  Comments inline.

>I would prefer to actually see == 0x378 in the code, because the
>hexademical number is what you see everywhere else, such as the BIOS POST
>and /proc/ioports. This also applies to 0x278 and 0x3BC below.
This is what I wanted but I could not figure out how do it.  If you tell me 
how I will be happy to change it.  I tried  if (p->base == 0x378) but then 
class_device_create does not get executed.

> > +	{
> > +		class_device_create(parallel_class, NULL, MKDEV(6, 0), NULL,
> > "lp0");
> > +		class_device_create(parallel_class, NULL, MKDEV(99, 0), NULL,
> > "parport0");
> > +	}
>Background info before: Because I burnt my on-board LPT port (applying too
>much volts or milliamps), I bought a dual-slot PCI add-in card. This card
>provides "parport1" and "parport2" at ports at 0xC800 and 0xC00
The last experience I have with off board cards was about 5 years ago.  The 
choices for the two parallel ports were 378, 278, or 3BC.  I was not aware 
that you had flexibility now.
>There are a number of problems in your code:
>1- testing just for 0x378/0x278/0x3BC is not enough
>2- parport0 could be 0xC800 (address may vary) if you do not
>    have any onboard LPT ports.
>     2=> that is why I think you should not reserver "lp0"/"parport0"
>         for 0x378.
As I said above I was not aware todays off board parallel ports had more 
choices.  I will see what I can do to fix this.  Do you have any 


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