[PATCH 0/2][SRU][OEM-6.0/Unstable] Fix USB4 PCIe hotplug on AMD Pink Sardine

You-Sheng Yang vicamo.yang at canonical.com
Tue Sep 27 08:18:12 UTC 2022

From: "You-Sheng Yang (vicamo)" <vicamo.yang at canonical.com>

BugLink: https://bugs.launchpad.net/bugs/1990922


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.


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 Phoenix/Phoenix2 platforms, only oem-6.0 and newer
are nominated for fix.

Mario Limonciello (2):
  thunderbolt: Explicitly reset plug events delay back to USB4 spec
  UBUNTU: SAUCE: thunderbolt: Explicitly enable lane adapter hotplug
    events at startup

 drivers/thunderbolt/switch.c  | 25 +++++++++++++++++++++++++
 drivers/thunderbolt/tb.h      |  1 +
 drivers/thunderbolt/tb_regs.h |  1 +
 drivers/thunderbolt/usb4.c    | 20 ++++++++++++++++++++
 4 files changed, 47 insertions(+)


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