Change in coreboot[master]: soc/intel/common/block/acpi: Return existing Object for _DSM subfunction

[Tim Wawrzynczak (Code Review)]

Attention is currently required from: Tim Wawrzynczak, Paul Menzel, Patrick Rudolph.
Hello build bot (Jenkins), Matt DeVillier, Shobhit Srivastava, Patrick Rudolph,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/61868

to look at the new patch set (#4).

Change subject: soc/intel/common/block/acpi: Return existing Object for _DSM subfunction
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soc/intel/common/block/acpi: Return existing Object for _DSM subfunction

Currently the LPIT Get Constraints _DSM subfunction returns a package
containing the path to a nonexistent device (\NULL). This is used to
work around an issue with Windows, where returning an empty package will
cause a BSOD.  However, using this non-existent device can also cause
confusion, as on Linux, it shows an error in dmesg, e.g.

ACPI Error: AE_NOT_FOUND, While resolving a named reference package
    element - \NULL (20200925/dspkginit-438)

Therefore, this patch modifies this returned package slightly to include
the path to ACPI_CPU_STRING for CPU 0, which should always be emitted on
Intel platforms that use the PEP driver.

Tested on google/brya0 on ChromeOS 5.10 kernel
Tested with current Windows 11 ISO

Signed-off-by: Tim Wawrzynczak 
Change-Id: If74a1620ff0de33bcdba06e1225c5e28c64253e1
---
M src/soc/intel/common/block/acpi/pep.c
1 file changed, 10 insertions(+), 5 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/68/61868/4