Instability/Crash with Promise Controller and Athlon Powersaving

[Nils Neumann <nilsn@gmx.net>]

Hello developer,

I don't know what it is, but it seems to be a bug in the promise code.

3 Test Computer

First : 
ECS K7VTA3 Bios 5.0c (newest), Promise PDC20268, Athlon 1800+, kernel 2.4.21 / 
2.4.22 / 2.4.23-rc1 / OS debian stable
Second :
EPOX, Promise PDC20262, Athlon 2600+ kernel 2.6.0test9 / OS gentoo
Third : 
ECS K7VZA3, Promise PDC20268, Duron 1333 (later : Duron 800), kernel 2.4.21 / 
2.4.22 / OS debian testing

Always the same ...
Everything works perfect, but when I enable the STPGNT-Mode (Stop Grant Mode) 
(-> http://www.daniel.nofftz.net/linux/) I get one problem : Writing (large 
files) to a disc on the promise controller. The speed is very slow, or the 
computer hangs after transfering 70-100 Mbyte, but some minutes later it 
works for the next 100 Mbyte. Sometimes the machine totally crashs, but I 
don't get any error messages. Everything else working perfect!!
I have only permanent access to the first configuration if there are 
questions. 

Thanks for help,
Nils 
(please : CC : kernel@knabber.homelinux.net)