Fix USB4 PCIe hotplug on AMD Pink Sardine

[You-Sheng Yang]

[SRU Justification]

[Impact]

For some reason that PCIe device hotplug is disabled once another OS
stack launches prior to Linux CM, which makes some registers not go
properly, so correct those registers to meet the default value of the
USB4 spec.

[Fix]

Two commits targeting v6.1 to restore the default values.

[Test Case]

To be verified from ODM side.

[Where problems could occur]

These two commits restores the default values as expected from USB4 spec
at being initialized, so it should be the right behaviour anyway.

[Other Info]

While this is for AMD Pink Sardine platforms, only oem-6.0 and newer
are nominated for fix.

========== original bug description ==========

For some reason that PCIe device hotplug is disabled once another OS stack launches prior to Linux CM, which makes some registers not go properly, so correct those registers to meet the default value of the USB4 spec.

https://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt.git/commit/?h=fixes&id=31f87f705b3c1635345d8e8a493697099b43e508

https://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt.git/commit/?h=next&id=5d2569cb4a65c373896ec0217febdf88739ed295

[You-Sheng Yang (vicamo)]

Included in experimental kernel linux-oem-6.0/jammy version 6.0.0-9004.4+exp.8 in https://launchpad.net/~canonical-hwe-team/+archive/ubuntu/intermediate-kernel.

[You-Sheng Yang (vicamo)]

SRU: https://lists.ubuntu.com/archives/kernel-team/2022-September/133485.html (oem-6.0, unstable)

[You-Sheng Yang (vicamo)]

The first commit 31f87f705b3c ("thunderbolt: Explicitly reset plug events delay back to USB4 spec value") has been merged into mainline v6.0, and the second one, commit 5d2569cb4a65 ("thunderbolt: Explicitly enable lane adapter hotplug events at startup") is now in linux-next for v6.1-rc1.

[You-Sheng Yang (vicamo)]

Landed in linux-oem-6.0/jammy version 6.0.0-1005.5.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-oem-6.0/6.0.0-1006.6 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-jammy' to 'verification-done-jammy'. If the problem still exists, change the tag 'verification-needed-jammy' to 'verification-failed-jammy'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Timo Aaltonen (tjaalton)]

fixed in 6.0 1006