[Linux-parport] Kernel & libieee1284 report BIOS ECP mode as EPP

Eddy De Greef edg1 at tiscali.be
Tue Sep 28 17:14:17 EDT 2004


on my PC, when the parallel port is set to (only) ECP mode in the
BIOS, the kernel reports that it supports EPP mode too (through
This can also be seen from the dmesg output:
parport0: PC-style at 0x378 (0x778), irq 7, dma 3
As a result, libieee1284 also reports the availability of EPP to the
application (a scanner driver in my case).
However, when the driver tries to access the port in EPP mode, this
works a few times and then libieee1284 gets stuck in a system call and
the driver hangs.

I've been able to reproduce this problem on my PC with recent 2.4
kernels and with the kernel.
I've had several reports of other people having the same problem on
different hardware.

When I set the BIOS to EPP or ECP+EPP, everything works fine.

I've been digging through the parport list archives, but I haven't
found anything on this issue. Is this a known problem?
Is there any chance that this will get solved?

Best regards,


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