[REGRESSION] mainline boot regression on AMD Stoney Ridge Chromebooks

[Laura Nao]

Hello,

KernelCI has identified a mainline boot regression [1] on the following
AMD Stoney Ridge Chromebooks (grunt family), between v6.8 (e8f897) and
v6.8-1185-g855684c7d938 (855684):
- Acer Chromebook Spin 311 R721T (codename kasumi360)
- HP Chromebook 14 (codename careena)
- HP Chromebook 11A G6 EE (codename barla)

The kernel doesn't boot at all and nothing is reported on the serial
console after "Starting kernel ...". The issue is still present on the
latest mainline revision.
The defconfig used by KernelCI for the boot tests can be found in [2].

Sending this report in order to track the regression while a fix is
identified.

Thanks,

Laura

[1] https://linux.kernelci.org/test/case/id/65fca98e3883a392524c4380/
[2]
https://storage.kernelci.org/mainline/master/v6.8-11837-g2ac2b1665d3fb/x86_64/x86_64_defconfig%2Bx86-board/gcc-10/config/kernel.config

#regzbot introduced: v6.8..v6.8-1185-g855684c7d938