[Bug 220904] New: [BUG] ucsi_acpi: USB 3.0 SuperSpeed not negotiated on USB-C hot-plug

[Bug 220904] New: [BUG] ucsi_acpi: USB 3.0 SuperSpeed not negotiated on USB-C hot-plug

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=220904

            Bug ID: 220904
           Summary: [BUG] ucsi_acpi: USB 3.0 SuperSpeed not negotiated on
                    USB-C hot-plug
           Product: Drivers
           Version: 2.5
    Kernel Version: 6.18.2-zen2-1-zen
          Hardware: Intel
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P3
         Component: USB
          Assignee: drivers_usb@kernel-bugs.kernel.org
          Reporter: thomas@jetzinger.com
        Regression: No

Created attachment 309074
  --> https://bugzilla.kernel.org/attachment.cgi?id=309074&action=edit
Kernel .config for 6.18.2-zen2-1-zen (Arch Linux zen kernel)

[1.] One line summary of the problem:
USB-C dock USB 3.0 devices fail to enumerate on hot-plug (only USB 2.0 works);
works at boot and on Windows

[2.] Full description of the problem/report:
On ThinkPad X1 Carbon Gen 11 with ThinkPad USB-C Dock Gen2 (40AS), USB 3.0
devices
(including ethernet adapter) do not enumerate when hot-plugging the dock. Only
USB 2.0
devices (audio, HID) enumerate. The same dock works correctly when connected at
boot,
and hot-plug works correctly on Windows 11, indicating this is a Linux driver
issue.

Detailed analysis:
- At boot: Dock connects via Thunderbolt 4 controller (0000:00:0d.0), USB 3.0
devices
  enumerate on Bus 2 (20Gbps SuperSpeed), ethernet (r8152) works
- On hot-plug: Thunderbolt USB buses report "root hub lost power or was reset"
but
  dock falls back to internal xHCI controller (0000:00:14.0) Bus 3 at USB 2.0
speeds only

The typec subsystem shows the issue:
- At boot: dock connects as port0-partner, port0 has USB connector bindings
  (usb2-port1, usb3-port1, usb4_port1)
- On hot-plug: dock may connect as port1-partner, but port1 has NO USB
connector
  bindings in ACPI (possible BIOS deficiency)
- Even when hot-plugging to port0: SuperSpeed lanes are not negotiated, only
USB 2.0

dmesg on hot-plug shows:
  usb usb1: root hub lost power or was reset
  usb usb2: root hub lost power or was reset
  usb 3-1: new high-speed USB device  <-- Only USB 2.0 enumeration, no
SuperSpeed

The UCSI driver does not appear to trigger USB 3.0 SuperSpeed lane
renegotiation
on partner connect. No typec connector binding messages appear on hot-plug.

Tested workarounds that do NOT fix the issue:
- xHCI controller unbind/rebind (echo 0000:00:0d.0 >
/sys/bus/pci/drivers/xhci_hcd/unbind)
- UCSI driver reload (modprobe -r ucsi_acpi && modprobe ucsi_acpi)
- Using either physical USB-C port

Working workaround: Boot with dock already connected.

[3.] Keywords (i.e., modules, networking, kernel):
ucsi_acpi, typec_ucsi, typec, USB-C, Thunderbolt, hot-plug, SuperSpeed,
xhci_hcd

[4.] Kernel information
[4.1.] Kernel version (from /proc/version):
Linux version 6.18.2-zen2-1-zen (linux-zen@archlinux) (gcc (GCC) 15.2.1
20251112, GNU ld (GNU Binutils) 2.45.1) #1 ZEN SMP PREEMPT_DYNAMIC Thu, 18 Dec
2025 18:00:58 +0000

[4.2.] Kernel .config file:
[Attached separately as kernel-config.txt]

[5.] Most recent kernel version which did not have the bug:
Unknown

[6.] Output of Oops.. message (if applicable) with symbolic information:
No kernel oops. The only relevant messages are:
  usb usb1: root hub lost power or was reset
  usb usb2: root hub lost power or was reset
And then USB 2.0-only enumeration on Bus 3 instead of SuperSpeed on Bus 2.

[7.] A small shell script or example program which triggers the problem (if
possible):
# Reproduce steps:
# 1. Boot system WITHOUT dock connected
# 2. Log in to desktop
# 3. Connect ThinkPad USB-C Dock Gen2 via USB-C cable
# 4. Check USB topology:
lsusb -t
# Expected: Dock on Bus 2 with 20000M devices
# Actual: Dock on Bus 3 with 480M devices only, Bus 2 empty

# Diagnostic commands:
ls /sys/class/typec/  # Shows port0-partner or port1-partner
ls /sys/class/typec/port0/usb*  # port0 has bindings
ls /sys/class/typec/port1/usb*  # port1 has NO bindings (ACPI issue?)
ip link show | grep enp  # Ethernet interface missing on hot-plug

[8.] Environment:
Hardware: Lenovo ThinkPad X1 Carbon Gen 11 (21HMCTO1WW)
BIOS: N3XET63W (1.38) dated 2025-10-08
Dock: ThinkPad USB-C Dock Gen2 (40AS), firmware 5.05.00
OS: Arch Linux (rolling)
Desktop: Hyprland (Wayland)

USB Controllers:
- 0000:00:0d.0: Intel Thunderbolt 4 (USB 3.2, buses 1+2)
- 0000:00:14.0: Intel Alder Lake xHCI (USB 3.1, buses 3+4)

ACPI USB-C controller: USBC000:00 with two ports (device:a2=port0,
device:a3=port1)

Related bug reports:
- Red Hat Bugzilla #2248484: UCSI driver bug
- Arch Linux Forum: https://bbs.archlinux.org/viewtopic.php?id=308325

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[Bug 220904] [BUG] ucsi_acpi: USB 3.0 SuperSpeed not negotiated on USB-C hot-plug

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=220904

Heikki Krogerus (heikki.krogerus@linux.intel.com) changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mika.westerberg@linux.intel
                   |                            |.com

--- Comment #1 from Heikki Krogerus (heikki.krogerus@linux.intel.com) ---
There are no logs here so I'm not completely sure what's going on, but the
symptoms sound very similar to a know issue with USB4/TBT where the PCI devices
fail to enumerate after resume.

This probable is not a Type-C issue, because this is UCSI system, and UCSI is
just a status interface. But you can always confirm that by disabling the ucsi
drivers before reproducing the issues.

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[Bug 220904] [BUG] ucsi_acpi: USB 3.0 SuperSpeed not negotiated on USB-C hot-plug

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=220904

--- Comment #2 from Thomas Jetzinger (thomas@jetzinger.com) ---
Created attachment 309097
  --> https://bugzilla.kernel.org/attachment.cgi?id=309097&action=edit
Disabling UCSI does NOT resolve the issue

Hi Heikki,

Here are the logs from two test scenarios. Both tests confirm the issue
persists regardless of UCSI driver status.

## System Info
 - ThinkPad X1 Carbon Gen 11 (21HMCTO1WW)
 - BIOS: N3XET63W (1.38)
 - Kernel: 6.18.2-zen2-1-zen (custom build, also tested on stock 6.12)
 - Dock: ThinkPad USB-C Dock Gen2 (40AS)

## Test 1: UCSI Enabled (Normal Configuration)

**Boot with dock connected:** USB 3.0 works
 - Ethernet (17ef:a387) on Bus 002 @ 5000M
 - USB3.1 Hub (17ef:a391) on Bus 002 @ 10000M

**After disconnect + reconnect:** USB 3.0 FAILS
 - Only USB 2.0 devices enumerate (480M on Bus 003)
 - Bus 002 (20Gbps SuperSpeed) is completely empty
 - Ethernet and USB 3.0 hub missing

Key log pattern:
 usb usb1: root hub lost power or was reset
 usb usb2: root hub lost power or was reset
 usb 3-3: new high-speed USB device number 14 using xhci_hcd  ← USB 2.0 only

## Test 2: UCSI Disabled (blacklist ucsi_acpi)

**Boot with dock connected:** USB 3.0 works (same as Test 1)

**After disconnect + reconnect:** USB 3.0 STILL FAILS
 - Identical failure pattern to Test 1
 - Same "root hub lost power or was reset" messages
 - Only high-speed (USB 2.0) enumeration

## Conclusion

Disabling UCSI does NOT resolve the issue. The problem appears to be in the
USB-C/Thunderbolt physical layer negotiation, not the UCSI driver. The repeated
"root hub lost power or was reset" messages on usb1/usb2 (Thunderbolt/USB4
buses) during hot-plug suggest the xHCI controller is being reset but failing
to re-enumerate SuperSpeed devices.

Full logs attached:
 - bug-220904-test1-ucsi-enabled.txt (Test 1 with UCSI)
 - bug-220904-test2-ucsi-disabled.txt (Test 2 without UCSI)

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[Bug 220904] [BUG] ucsi_acpi: USB 3.0 SuperSpeed not negotiated on USB-C hot-plug

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https://bugzilla.kernel.org/show_bug.cgi?id=220904

--- Comment #3 from Mika Westerberg (mika.westerberg@linux.intel.com) ---
Can you attach full dmesg of the repro with "thunderbolt.dyndbg=+p" in the
kernel command line?

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[Bug 220904] [BUG] ucsi_acpi: USB 3.0 SuperSpeed not negotiated on USB-C hot-plug

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=220904

--- Comment #4 from Thomas Jetzinger (thomas@jetzinger.com) ---
Created attachment 309100
  --> https://bugzilla.kernel.org/attachment.cgi?id=309100&action=edit
full dmesg with thunderbolt.dyndbg=+p

Kernel: 6.18.2-arch2-1

Repro: Boot with dock → ethernet works. Unplug/replug dock → ethernet gone.

Key logs:
- Boot: cdc_ether registered at usb-0000:00:0d.0-3.1
- Unplug [178.9s]: r8152-cfgselector disconnect, cdc_ether unregister
- Replug [189.1s]: Thunderbolt resumed, USB hubs + HID + audio re-enumerated
- Ethernet (2-3.1) never re-registered

Note: "r8152-cfgselector: Unknown version 0x0000" at boot - driver falls back
to cdc_ether.

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[Bug 220904] [BUG] ucsi_acpi: USB 3.0 SuperSpeed not negotiated on USB-C hot-plug

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https://bugzilla.kernel.org/show_bug.cgi?id=220904

--- Comment #5 from Mika Westerberg (mika.westerberg@linux.intel.com) ---
Okay thanks! This dock is not TB/USB4 so not related to USB4 link. I wonder if
you tried to disable runtime PM from the 0d.0 xHCI?

# echo on > /sys/bus/pci/devices/0000:00:0d.0/power/control

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[Bug 220904] [BUG] ucsi_acpi: USB 3.0 SuperSpeed not negotiated on USB-C hot-plug

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https://bugzilla.kernel.org/show_bug.cgi?id=220904

--- Comment #6 from Thomas Jetzinger (thomas@jetzinger.com) ---
Thanks Mika, your xHCI runtime PM suggestion was correct.

Root cause: /sys/bus/pci/devices/0000:00:0d.0/power/control was auto.

Fix: Removed xhci_hcd from TLP's RUNTIME_PM_DRIVER_DENYLIST so TLP sets xHCI to
on on AC.

Result: Hot-plug works. Dock enumerates on USB 3.0 with ethernet at 5000M.

Note: TLP ships with xhci_hcd in the default denylist (defaults.conf), leaving
xHCI at kernel default (auto).

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[Bug 220904] [BUG] ucsi_acpi: USB 3.0 SuperSpeed not negotiated on USB-C hot-plug

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--- Comment #7 from Mika Westerberg (mika.westerberg@linux.intel.com) ---
These ports should wake up on plug. Summoning Mathias if he has any ideas why
it is not working.

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[Bug 220904] [BUG] ucsi_acpi: USB 3.0 SuperSpeed not negotiated on USB-C hot-plug

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--- Comment #8 from Thomas Jetzinger (thomas@jetzinger.com) ---
After further testing, I can confirm that the USB ports also fail to recover
after suspend/resume cycles. Will share logs later.

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[Bug 220904] [BUG] ucsi_acpi: USB 3.0 SuperSpeed not negotiated on USB-C hot-plug

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--- Comment #9 from Mathias Nyman (mathias.nyman@linux.intel.com) ---
The log entries about 'root hub lost power or was reset' means
xHC controller failed to resume properly, and will be reset and re-initialized.

There are no other log entries after this from that xHC, so it's possible
there is something failing during re-initialization.

could you enable xhci and usb core dynamic debug and send a new dmesg of a
failing case:

echo 'module xhci_hcd =p' >/sys/kernel/debug/dynamic_debug/control
echo 'module usbcore =p' >/sys/kernel/debug/dynamic_debug/control

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--- Comment #10 from Thomas Jetzinger (thomas@jetzinger.com) ---
Created attachment 309154
  --> https://bugzilla.kernel.org/attachment.cgi?id=309154&action=edit
Tested with dynamic debug enabled. s2idle suspend/resume issue:

After resume, Thunderbolt xHCI (00:0d.0) reports "root hub lost power":

  usb usb1: root hub lost power or was reset
  usb usb2: root hub lost power or was reset
  usb 2-3: Waited 2000ms for CONNECT
  usb 2-3: can't resume, status -19
  usb 2-3: USB disconnect
  r8152-cfgselector 2-3.1: USB disconnect

All USB3 devices on Bus 2 disconnect and don't recover. Requires reboot.

Full dmesg with xhci_hcd and usbcore debug attached.

Kernel: 6.18.3-arch1-1

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