Messages in this thread | | | Date | Fri, 11 Jul 2003 21:04:39 +0000 | From | xi <> | Subject | Re: AMD760MPX: bogus chispset ? (was PROBLEM: sound is stutter, sizzle with lasts kernel releases) |
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Alan Cox wrote: > On Gwe, 2003-07-11 at 18:02, xi wrote: > >>Now I have done some investigations, and I think I have found the >>problem: It has appeared between kernel-2.4.18-pre9 and kernel-2.4.18-rc1 >>If I am not wrong, between these two versions, Alan Cox did a change in >>drivers/pci/quirks.c and this is this change which cause the problem. > > > As I read the documentation the other change is also required in this > situation to avoid a chipset lockup. It might be worth you rechecking > the AMD errata docs for 762/768 again to be sure I didnt screw up and > there are not newer rules for other revisions. >
Ok, I have rechecked the errata docs. I have not found any recommandation change for PCI compliance configuration registers.
And one interesting thing: in the AMD762 datasheet (24462.pdf) page 231 (Recommanded BIOS settings), I can see this: "Numerical Values shown with h or b are preferred settings." ; and AMD recommand this: -> set bits 2 and 1 of register 0x4C to "0b" -> set bits 23 and 3 respectively to "0b" and "1b"
I can confirm that these settings works much more better, even if they don't exactly follow PCI specs. And I don't think this is specific to my cards since I have tested others. Furthermore, my AMD762 is revision B1 (just before the last one: C0), and my AMD768 revision is B2, the last one.
Would you accept I make a patch which doesn't make any change in these registers at least up to AMD762 revision B1 (ie keeping recommanded values from AMD) ? Or could you propose an other solution ?
Regards, Xavier
-- E-mail: ctrl.alt.sup@free.fr xizard@chez.com Please no longer use xizard@enib.fr, this e-mail will be removed soon.
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