Re: [PARPORT] "Device or resource busy" on loading parport_pc


Greg Ward (gward@ase.com)
Sat, 16 Jan 1999 21:42:39 -0500


On Sat, Jan 16, 1999 at 08:04:44AM +0000, Tim Waugh wrote:
> On Fri, 15 Jan 1999, Greg Ward wrote:
>
> > # insmod parport_pc
> > /lib/modules/2.2.0-pre7/misc/parport_pc.o: init_module: Device or resource busy
> >
> > *Which* device or resource is busy? Is there any way to find out?
>
> Yes - take a look at what "dmesg" says. It should give you a hint as to
> what's going wrong. This kind of thing is usually because of IO space or
> IRQ line, but since you didn't give parport_pc any options it shouldn't be
> either of those.

Well, there's good news and there's bad news. The bad news is that
"dmesg" didn't help much; it just told me that ppa was looking at port
0x378, which is right because that's where my parallel port is, and
that's what ppa was using successfully under Linux 2.0.36.

The good news is, I got things working by tweaking my CMOS. It would
appear that my motherboard is broken; it claims to offer ECP, EPP, and
ECP+EPP modes; I was using its ECP+EPP mode, but ppa under Linux 2.0.36
complained about this:

ppa: Probing port 0378
ppa: SPP port present
ppa: ECP with a 16 byte FIFO present
ppa: PS/2 bidirectional port present
ppa: Failed Intel bug check. (Phony EPP in ECP)
ppa: Found device at ID 6, Attempting to use EPP 32 bit
ppa: Communication established with ID 6 using EPP 32 bit

When I rebooted and tweaked the CMOS to put the parallel port in ECP
mode, I get this under Linux 2.0.36:

ppa: Probing port 0378
ppa: SPP port present
ppa: ECP with a 16 byte FIFO present
ppa: PS/2 bidirectional port present
ppa: Passed Intel bug check.
ppa: Found device at ID 6, Attempting to use EPP 32 bit
ppa: Found device at ID 6, Attempting to use PS/2
ppa: Communication established with ID 6 using PS/2

which looks a little healthier. Best of all, when I leave the parallel
port in ECP mode and boot Linux 2.2.0-pre7, parport and ppa work:

parport0: PC-style at 0x378 [SPP,PS2,ECP,ECPPS2]
ppa: Version 2.03 (for Linux 2.0.0)
ppa: Found device at ID 6, Attempting to use EPP 16 bit
ppa: Found device at ID 6, Attempting to use PS/2
ppa: Communication established with ID 6 using PS/2

Yayyh!!

So, you might want to consider beefing up the error messages in parport
or ppa, or maybe add a note describing this potential pitfall to the
documentation. At the very least, you can add it to your bag o' tricks
to suggest to other people having problems under 2.2.0 with parport/ppa
where ppa worked fine under 2.0.x.

Hey, I just noticed that ppa's announce line says "for Linux 2.0.0" --
is that right??!?

Thanks for the reply --

        Greg

-- 
Greg Ward, programmer-at-large        email: gward@ase.com

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