>>> About 50% of *all* VLB systems have this problem,
>> Fifty percent? How do you derive that number?
>All Gateway-2000 386/486 systems had this problem for about a year.
>GW2000 owns a huge piece of the market, and other companies were
>also using the same chips -- including other biggies like DELL.
The CMD640 and RZ1000 problems are well known, and defensive
programming of the chipset can circumvent the problem. FreeBSD does
so without any need to disable interrupts during IDE disk I/O.
>Again, the problem occurs rarely (usually required simultaneous floppy
>use).
Even if your estimate of 50% is accurate, by this time in 1997, the
percentage of Linux users with such systems would certainly be a very
small minority.
With such a small number of users to be affected, It would be much
better to enable interrupts during IDE disk I/O in the kernel and give
users a LILO/LOADLIN parameter to override the default behavior.
The various distributions could even apply the override in their boot
disks if they were fearful of negative user feedback.
Changing the Linux kernel default to ENABLE interrupts during IDE disk
I/O would be FAR SUPERIOR to probing for a recognizable PCI controller
in an effort to determine whether it seems "safe" to enable interrupts
during IDE disk I/O. With so many PCI users now, why go to such great
lengths merely to maintain a Linux tradition?
Any why be hidebound by tradition? Just change the default and give
users a boot-time parm to override it!
John