On Thu, Dec 12, 2013 at 7:02 AM, Kyösti Mälkki kyosti.malkki@gmail.com wrote:
Hi
After commit 872c922 there is some trouble on PCI configuration access with Asus M4A785-M. This could apply to other amdfam10 too, although I have not yet received such reports.
As the commit message stated, I had discovered that in the beginning of ramstage all PCI configuration access used the IO (0xcf8) method even though Kconfig specified MMCONF_SUPPORT_DEFAULT which should imply all PCI config access is done with MMCONF unless IO is explicitly requested.
AFAICS, for all cores the MSR enabling MMCONF is programmed very early in the romstage. So second option for failure is there exists cases where IO must be used instead of MMCONF, but I could not find such documentation yet.
I hope Dennis can reproduce the failure log and post it in the next few days.
Which devices weren't working? IIRC, on old AMD processors rev E and maybe rev F the northbridge config space couldn't be accessed by MMCONF -- only the cf8/cfc method.
-Aaron