Messages in this thread | | | Date | Mon, 30 Aug 2004 13:20:31 -0400 (EDT) | From | "Richard B. Johnson" <> | Subject | Re: Celistica with AMD chip-set |
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On Mon, 30 Aug 2004, Andi Kleen wrote:
> Alan Cox <alan@lxorguk.ukuu.org.uk> writes: > > > On Llu, 2004-08-30 at 15:02, Richard B. Johnson wrote: > >> Hello all, > >> > >> The Celistica server with the AMD chip-set has very poor > >> PCI performance with Linux (and probably W$ too). > >> > >> The problem was traced to incorrect bridge configuration > >> in the HyperTransport(tm) chips that connect up pairs > >> of slots. > > > while((pdev = pci_find_device(0x1022, 0x7450, pdev)) != NULL) > > pci_write_config_dword(pdev, 0x4c, 0x2ec1); > > > > Can you get Celestica to mail me their PCI subvendor > > id/devid's for the problem configuration or DMI strings > > and then we can do a PCI quirk properly for this. > > Celistica is just the contract manufacturer for the AMD > reference design, they're really AMD designs. 0122/7450 > is the AMD 8131 PCI-X bridge. > > I doubt it is a good idea to blindly change the configuration of the > bridge like this in the kernel. It is probably better to wait for an > BIOS update or if you really need an urgent fix to do it from user > space. Any fix should probably read/change bit/write the register, not > blindly overwrite. > > -Andi > It is NOT "blindly" overwritten. We know what was in that register (0x2c01).
Also, it is a "fix" for those who are getting crappy performance from their boxes. Hopefully a new BIOS will be out with more permanent fixes.
Cheers, Dick Johnson Penguin : Linux version 2.4.26 on an i686 machine (5570.56 BogoMips). Note 96.31% of all statistics are fiction.
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