[coreboot] [RFH] Native AMD fam10-15 support

[qtux]

On 15/06/18 02:42, Kyösti Mälkki wrote:
> On Thu, Jun 14, 2018 at 4:38 AM, qtux <mail at qtux.eu> wrote:
>> On 13/06/18 22:12, Kyösti Mälkki wrote:
>> Hi,
>>
>> S3 is __not__ working on my KCMA-D8. The last time I tried, I had to
>> remove the power cord for a couple of seconds to be able to boot again.
>>
>> Interestingly, this issue looks similar to another one I had with a
>> flash chip which seems not to be supported by coreboot. Here the
>> relevant part of the logs regarding the bad chip:
>> Manufacturer: ef
>> SF: Unsupported Winbond ID 4014
>> SF: Unsupported manufacturer!
>>
> 
> Thanks, [1] should take care of this.
> 

Thank you! I will test the Winbond chip when I find some time to do so.

>> Coreboot did work well, but froze sometimes when booting during the
>> assigning resources step (more or less exactly after assigning the PCI
>> 14.3 or PNP 002e.2 device, which happen to be close to each other inside
>> the devicetree). I had to remove the power cord in order to be able to
>> boot again (or to get the next random freeze...). Rarely, after such an
>> recovery, I have got flooded by IOMMU warnings in Linux which would only
>> disappear after another reboot.
> 
> Ah, that resume reboot-loop issue. The bit that tells to do S3 resume
> is a sticky register backed up by Vstb rail. With [2] you should not
> need to do full power-cycling at least. We should extend this work to
> other platforms.
> 

I am not sure whether the term resume reboot-loop applies for my issue
(side note: I used a serial connection to monitor the boot process):

Rebooting (via holding the power button for some seconds) after
encountering a freeze (aka stopping at the assign resource step)
resulted into having no output from serial at all. I could repeat this
with no effect at all, the computer seemed to be dead. Only removing the
power cord could solve the issue.

This issue could occur when rebooting but even when cold booting.

>> Replacing the chip seems to have solved this random boot freeze problem.
>> But maybe the S3 issue and the issue I had with the wrong chip are
>> related as they both lock down the machine until I remove the power cord.
> 
> Yes, it's connected. Having a non-supported SPI part ID there would
> prevent ACPI S3 resume, and likely enter the loop.>

Just to be sure: The S3 resume does not work with the __supported__ SPI
chip. I did not test S3 with the unsupported one.

> If someone takes the task of testing and/or bisecting please note:
> 
> Regression present between: 714709f .. a26377b
> 
> Regression present between: 9e94dbf .. c2a921b (for kcma-d8) 8a8386e
> (for kgpe-d16)
> 
> Now, since commit babb2e6 that claims to add S3 support on kgpe-d16 is
> within the latter period, I do not quite see how S3 support could have
> worked with that commit on kgpe-d16.  Or maybe this feature was never
> retested once it was rebased and upstreamed. Nor can I see how it
> could have worked for any commit in 4.6, so I must be missing
> something here. So I will need some logs.
> 
> 
> [1] https://review.coreboot.org/#/c/coreboot/+/27107
> [2] https://review.coreboot.org/#/c/coreboot/+/27108
> 
> Kyösti
> 

Answers are inside the text.
I forgot to mention that I am currently on commit 793ae846e8.

Cheers,
Matthias