[coreboot] AMD DBM690T PowerNow table problems

Carl-Daniel Hailfinger c-d.hailfinger.devel.2006 at gmx.net
Fri Jan 9 10:05:31 CET 2009

On 08.01.2009 17:52, Marc Jones wrote:
> On Wed, Jan 7, 2009 at 7:34 PM, Carl-Daniel Hailfinger
> <c-d.hailfinger.devel.2006 at gmx.net> wrote:
>> On 06.01.2009 17:47, Marc Jones wrote:
>>> On Mon, Jan 5, 2009 at 6:36 PM, Bao, Zheng <Zheng.Bao at amd.com> wrote:
>>>> If fid_multiplier is 0, it doesn't seem to have any sense. So I agree.
>>>> Acked-by: zheng bao <zheng.bao at amd.com>
>>> I also fixed this in acpi_tables.c Pistachio.
>>> r 3847
>> Thanks!
>> The Linux kernel powernow-k8 driver doesn't complain anymore, but now
>> the machine will lock up or reboot once I put some load on it.
>> Blacklisting the powernow-k8 driver avoids the issue, but that makes
>> frequency scaling impossible.
>> AFAICS the standard cpu frequency governor is ondemand and it scales the
>> frequency down from 1800 MHz to 1000 Mhz. That seems to work fine, but
>> scaling up again will cause the lockups/reboots. By the way, coreboot
>> reports a BIST failure after such reboots. Not nice.
>> Rudolf's PowerNow tables had entries for 1000/1600/1800 MHz. The
>> proprietary BIOS and coreboot only have entries for 1000/1800 MHz.
>> According to the docs, scaling from 1000 MHz to 1800 MHz can't be done
>> in a single step. Is that maybe the reason for the problems I'm seeing?
> Can you dump the current tables or can you not get that far before a
> crash? The entries are end points and the driver takes care of the
> stepping that needs to be done to get to those points. We need to
> check that the table generated the correct vid setting for the fid. It
> is well described in the bkdg section 10.6.

I managed to boot fine with the proprietary BIOS, blacklisted the
k8-powernow driver and rebooted with coreboot.

Attached are the following files:
_PSS with coreboot (crash)
_PSS with proprietary BIOS (ok)

If I combine the _PSS from the proprietary BIOS with the other tables
from coreboot, the machine does not crash. I'll try to narrow it down



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