Re: CMD640B detection bug

Dirk Peter van der Werf (dirkp@pc54.ph.rhbnc.ac.uk)
Fri, 8 Mar 1996 09:21:41 +0000 (GMT)

Ulrich wrote
>
> I know a board where you can disable the built-in CMD640B. When you
> boot a Linux kernel with support for it compiled in, the kernel still
> detects the chip, but gives an error message that the CMD640 can't be
> reset sucessfully. Maybe someone can find out how to detect that the
> CMD640 is disabled.
>
> Just wanted to mention it.
>
> Ulrich
>

I have a Gateway 2000 P4D-100. It has a built in CMD640.
A 1G disk and a NEC cdrom at ide0 and a 540 M DISK at ide1.

Even with the chip enabled, the 1.3 kernels cannot reset the second ide.
In 1.3.59 it was possible to set CMD640_NORMAL_INIT to 0 in cmd640.c,
but this option is dissapeared in the later versions. Although I
found the part in the cmd640.c file wich can be disabled in 1.3.59, I
do not know if it is save to disable this part in the later versions.

By the way, with a high load on the disks, the system often hangs, while the
disk light is burning. I thought it was due to the CMD640B, and I am thinking
in buying another ide chip. But I read that also other chipsets have the same
problem.

Cheers,

Dirk Peter

-- 
D. P. van der Werf    
Department of Physics 
Royal Holloway        
University of London  
Egham                 
Surrey TW20 OEX       
Tel +44 1784 443457
Fax +44 1784 472794
e-mail: dirkp@pc54.ph.rhbnc.ac.uk