Re: [2.1.98 - CVS] PCI Quirks addition..

Gerard Roudier (groudier@club-internet.fr)
Sat, 2 May 1998 21:38:28 +0200 (MET DST)


On Fri, 1 May 1998, Aaron Tiensivu wrote:

[...]

> I no longer have to bootstrap into DOS with this addition to the pci-quirks
> file. It seems to be register compatible with the Mercury/etc/etc chipsets.
>
> The bootup messages after this patch is applied:
>
> PCI: PCI BIOS revision 2.10 entry at 0xf9eb0
> PCI: Using configuration type 1
> PCI: Probing PCI hardware.
> PCI: 00:28 [8086/0486]: Bridge optimization (00)
> Cache L2: Not supported.
> CPU-PCI posted write: off.Changed! Now on.
> CPU-Memory posted write: on.
> PCI-Memory posted write: off.Changed! Now on.
> PCI burst: off.Changed! Now on.

I donnot think that enabling burst is dangerous, but the 2 other
so called _optimizations_ could be risky IMO.
The BIOS seems not to enable Posted Write in the both directions of
the PCI host bridge. The reasons could be that the bridge might
not behave correctly with regards to PCI ordering rules for bridge.
If it is the case, this quirks management has broken your system.
BTW, some old Intel chipsets are known to be broken for posted
write.

> Which is exactly what I used to do manually with the old ctchip program.
> I really like the layout of pci-quirks. It made this addition really trivial.

In my opinion, the pci-quirks just worked in the opposite direction and
may have broken things instead of having fixed them.

Gerard.

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