Re: [PARPORT] BackPack Cdrom Woes


grant@torque.net
Wed, 22 Jul 1998 20:31:24 -0400 (EDT)


> > But you haven't actually told us if the pd driver detected EPP mode ...
>
> well, whenever i start up parport, it informs me via the log message that :
>
> parport0: PC-style at 0x378, irq 7, dma 3 [SPP,PS2,ECP,ECPPS2]

There's no EPP there, but that's parport's opinion. I want to know what
epat says. When you load pd with the SparQ attached, the epat protocol
module tells you what mode it found.

> parport0: PC-style at 0x378, irq 7, dma 3 [SPP,ECP,ECPPS2]

No EPP there, either.

> IF i reboot the laptop, and then change the bios, and then boot linux,
> it detects only the SPP mode. Could the bios not be changing the PC87338
> chip properly

Exactly.

> (does linux totally manage all of the hardware or does the bios still
> have some say ?)

The BIOS is generally responsible for setting up the initial state of
the hardware. The parallel port chips can be wired up in different ways,
and some have registers that only appear after you sacrifice a black
crow at midnight while whispering a special incantation.

(A common trick is to enable the configuration registers only if a
specific sequence is written in rapid succession to a single io address.)

Since most good BIOSes make all the different port settings available,
we haven't made it a high priority to detect and reinitialise the chips.

More and more BIOSes seem to be limiting the number of available
selections - so it's becoming more urgent for us to solve this problem.

> LPT = 0378, E0 E0 FF 00 07
> Bidirectional
> Chipset : NatSemi PC87338
> Mode : Bidirectional

Did you try using it with -epp to force the chip into EPP mode ?

(If that works, we can probably solve this problem before too long.)

> does MSI have a nd policy ? could / would it be possible for me to
> get technical ref. out of them if i was willing to sign one (i know nd usually
> also applies to source code, which could get into the stick situation that we
> are in with the neomagick chipset driver for Xwindows atm)

MSI does not release technical information to anyone. Full stop. Forget
this. There are MSI people reading this mailing list, and they do what
they can to help, but they cannot release any of the company's secrets.

Everything we know about the MSI products has been obtained by reverse
engineering.

Whenever we encounter a situation like yours, we do traces, analyse them,
and enhance the driver. It is a continuous game of catch up.

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Grant R. Guenther grant@torque.net
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