daisy chained thunderbolt devices not working at reboot on AMD strix platforms

[You-Sheng Yang]

[SRU Justification]

[Impact]

Devices on PCIe bus on some AMD based systems may not function normally.

Boot firmware (typically BIOS) might have created tunnels of its own. The tunnel configuration that it does might be sub-optimal. For instance it may only support HBR2 monitors so the DisplayPort tunnels it created may limit Linux graphics drivers. In addition there is an issue on some AMD based systems where the BIOS does not allocate enough PCIe resources for future topology extension.

[Fix]

4 commits already in upstream linux repo that resets USB4 v1 routers in addition to already reset v2 routes to align the behavior with Windows Connection Manager.

[Test Case]

On affected platforms with monitor connected across reboots, the DUT reboots into linux with blank screen. This should turn it back to normal as expected.

[Where problems could occur]

No. The reset triggers Linux to re-allocate necessary resources for its own, and this is what Windows does, too.

[Other Info]

While this is in v6.9-rc1 and backported to stable at v6.8.8, Noble and oem-6.8 are nominated.

========== original but report ==========

Boot firmware (typically BIOS) might have created tunnels of its own. The tunnel configuration that it does might be sub-optimal. For instance it may only support HBR2 monitors so the DisplayPort tunnels it created may limit Linux graphics drivers. In addition there is an issue on some AMD based systems where the BIOS does not allocate enough PCIe resources for future topology extension. By resetting the USB4 topology the PCIe links will be reset as well allowing Linux to re-allocate.

This aligns the behavior with Windows Connection Manager.

Fixes merged to linus tree for v6.9-rc1:
* 59a54c5f3dbde thunderbolt: Reset topology created by the boot firmware
* ec8162b3f0683 thunderbolt: Make tb_switch_reset() support Thunderbolt 2, 3 and USB4 routers
* b35c1d7b11da8 thunderbolt: Introduce tb_path_deactivate_hop()
* 01da6b99d49f6 thunderbolt: Introduce tb_port_reset()

[You-Sheng Yang (vicamo)]

SRU:
* https://kernel.ubuntu.com/gitea/kernel/noble-linux-oem/pulls/3 (oem-6.8)

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

This bug is awaiting verification that the linux-oem-6.8/6.8.0-1006.6 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-noble-linux-oem-6.8' to 'verification-done-noble-linux-oem-6.8'. If the problem still exists, change the tag 'verification-needed-noble-linux-oem-6.8' to 'verification-failed-noble-linux-oem-6.8'.

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!

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux-oem-6.8 - 6.8.0-1006.6

---------------
linux-oem-6.8 (6.8.0-1006.6) noble; urgency=medium

  * noble/linux-oem-6.8: 6.8.0-1006.6 -proposed tracker (LP: #2064336)

  * Packaging resync (LP: #1786013)
    - debian.oem/dkms-versions -- update from kernel-versions (main/2024.04.29)

  * Resync CI Runner Configuration (LP: #2024199)
    - [CI] resync ci configuration

  * AMD Strix s2idle failure due to AMD VPE driver init (LP: #2065365)
    - drm/amdgpu/vpe: power on vpe when hw_init

  * daisy chained thunderbolt devices not working at reboot on AMD strix
    platforms (LP: #2058333)
    - thunderbolt: Introduce tb_port_reset()
    - thunderbolt: Introduce tb_path_deactivate_hop()
    - thunderbolt: Make tb_switch_reset() support Thunderbolt 2, 3 and USB4
      routers
    - thunderbolt: Reset topology created by the boot firmware

  * Update amd_sfh for AMD strix series (LP: #2058331)
    - HID: amd_sfh: Increase sensor command timeout
    - HID: amd_sfh: Improve boot time when SFH is available
    - HID: amd_sfh: Extend MP2 register access to SFH
    - HID: amd_sfh: Set the AMD SFH driver to depend on x86

  * Update amd-pmf for AMD strix series (LP: #2058330)
    - platform/x86/amd/pmf: Differentiate PMF ACPI versions
    - platform/x86/amd/pmf: Disable debugfs support for querying power thermals
    - platform/x86/amd/pmf: Add support to get sbios requests in PMF driver
    - platform/x86/amd/pmf: Add support to notify sbios heart beat event
    - platform/x86/amd/pmf: Add support to get APTS index numbers for static
      slider
    - platform/x86/amd/pmf: Add support to get sps default APTS index values
    - platform/x86/amd/pmf: Update sps power thermals according to the platform-
      profiles

  * Miscellaneous Ubuntu changes
    - [Config] Update config after rebase.

  [ Ubuntu: 6.8.0-34.34 ]

  * noble/linux: 6.8.0-34.34 -proposed tracker (LP: #2065167)
  * Packaging resync (LP: #1786013)
    - [Packaging] debian.master/dkms-versions -- update from kernel-versions
      (main/2024.04.29)

  [ Ubuntu: 6.8.0-32.32 ]

  * noble/linux: 6.8.0-32.32 -proposed tracker (LP: #2064344)
  * Packaging resync (LP: #1786013)
    - [Packaging] drop getabis data
    - [Packaging] update variants
    - [Packaging] update annotations scripts
    - [Packaging] debian.master/dkms-versions -- update from kernel-versions
      (main/2024.04.29)
  * Enable Nezha board (LP: #1975592)
    - [Config] Enable CONFIG_REGULATOR_FIXED_VOLTAGE on riscv64
  * Enable Nezha board (LP: #1975592) // Enable StarFive VisionFive 2 board
    (LP: #2013232)
    - [Config] Enable CONFIG_SERIAL_8250_DW on riscv64
  * RISC-V kernel config is out of sync with other archs (LP: #1981437)
    - [Config] Sync riscv64 config with other architectures
  * obsolete out-of-tree ivsc dkms in favor of in-tree one (LP: #2061747)
    - ACPI: scan: Defer enumeration of devices with a _DEP pointing to IVSC device
    - Revert "mei: vsc: Call wake_up() in the threaded IRQ handler"
    - mei: vsc: Unregister interrupt handler for system suspend
    - media: ipu-bridge: Add ov01a10 in Dell XPS 9315
    - SAUCE: media: ipu-bridge: Support more sensors
  *...

[You-Sheng Yang (vicamo)]

Noble Ubuntu-6.8.0-38.38 ships with v6.8.8 stable fixes.