[Linux-parport] pf: Oops with Imation SuperDisk

Adam Baker parport at baker-net.org.uk
Mon Jul 4 15:39:15 EDT 2005

On Sunday 03 July 2005 12:47, Ondrej Zary wrote:
> I've tried to use my external Imation SuperDisk parallel port drive in
> Linux 2.6.12 but failed. The drive is detected properly but when I try
> to mount a floppy, I get errors (they look like timeouts), the system is
> unresponsive (even framebuffer cursor stops blinking) and then it oopses
>   (see below). Also when I configure the port to ECP/EPP in BIOS, the
> driver is unable to use any EPP mode (uses 8-bit and the oops is the same).

If EPP is enabled in the BIOS but can't be detected you may be suffering from 
the same issue as I and some others have found, the lines around line 1880 in 

        /* Check for Intel bug. */
        if (priv->ecr) {
                unsigned char i;
                for (i = 0x00; i < 0x80; i += 0x20) {
                        ECR_WRITE (pb, i);
                        if (clear_epp_timeout (pb)) {
                                /* Phony EPP in ECP. */
                                return 0;

Incorrectly identify your parallel port as being one with broken EPP support. 
If you are able to recompile the parport_pc module with those lines commented 
out and retest it I'd be interested to hear the result. It would also be 
useful to know what motherboard you have and what SuperIO chip is on it.

I found that the onscsi driver used to generate random hangs in the kernel 
until I removed those lines to get EPP support working so this MAY explain 
the problem you are getting.

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