[SRU][Q/R][PATCH 0/3] Ease the sysfs call trace which comes from ucsi firmware issue

[AceLan Kao]

From: "Chia-Lin Kao (AceLan)" <acelan.kao at canonical.com>

BugLink: https://bugs.launchpad.net/bugs/2127960

[Impact]
We'll see this call trace while plugged tbt device

Sep 24 13:24:22 ubuntu-202504-36599 kernel: sysfs: cannot create duplicate filename '/devices/platform/USBC000:00/typec/port0/port0.0/partner'
Sep 24 13:24:22 ubuntu-202504-36599 kernel: CPU: 1 UID: 0 PID: 132 Comm: kworker/u64:1 Tainted: G O 6.14.0-1012-oem #12-Ubuntu
Sep 24 13:24:22 ubuntu-202504-36599 kernel: Tainted: [O]=OOT_MODULE
Sep 24 13:24:22 ubuntu-202504-36599 kernel: Hardware name: Dell Inc. /, BIOS x.x.x xx/xx/2025
Sep 24 13:24:22 ubuntu-202504-36599 kernel: Workqueue: USBC000:00-con1 ucsi_poll_worker [typec_ucsi]
Sep 24 13:24:22 ubuntu-202504-36599 kernel: Call Trace:
Sep 24 13:24:22 ubuntu-202504-36599 kernel: <TASK>
Sep 24 13:24:22 ubuntu-202504-36599 kernel: dump_stack_lvl+0x76/0xa0
Sep 24 13:24:22 ubuntu-202504-36599 kernel: dump_stack+0x10/0x20
Sep 24 13:24:22 ubuntu-202504-36599 kernel: sysfs_warn_dup+0x8a/0xb0
Sep 24 13:24:22 ubuntu-202504-36599 kernel: sysfs_do_create_link_sd+0xf1/0x100
Sep 24 13:24:22 ubuntu-202504-36599 kernel: sysfs_create_link+0x21/0x50
Sep 24 13:24:22 ubuntu-202504-36599 kernel: typec_probe+0x7e/0x100 [typec]
Sep 24 13:24:22 ubuntu-202504-36599 kernel: ? driver_sysfs_add+0x66/0xd0
Sep 24 13:24:22 ubuntu-202504-36599 kernel: really_probe+0xee/0x3c0
Sep 24 13:24:22 ubuntu-202504-36599 kernel: __driver_probe_device+0x8c/0x180
Sep 24 13:24:22 ubuntu-202504-36599 kernel: driver_probe_device+0x24/0xd0
Sep 24 13:24:22 ubuntu-202504-36599 kernel: __device_attach_driver+0xcd/0x170
Sep 24 13:24:22 ubuntu-202504-36599 kernel: ? _pfx__device_attach_driver+0x10/0x10
Sep 24 13:24:22 ubuntu-202504-36599 kernel: bus_for_each_drv+0x94/0xf0
Sep 24 13:24:22 ubuntu-202504-36599 kernel: __device_attach+0xb6/0x1d0
Sep 24 13:24:22 ubuntu-202504-36599 kernel: device_initial_probe+0x13/0x20
Sep 24 13:24:22 ubuntu-202504-36599 kernel: bus_probe_device+0x9f/0xb0
Sep 24 13:24:22 ubuntu-202504-36599 kernel: device_add+0x513/0x710
Sep 24 13:24:22 ubuntu-202504-36599 kernel: device_register+0x1a/0x30
Sep 24 13:24:22 ubuntu-202504-36599 kernel: typec_register_altmode+0x253/0x3a0 [typec]
Sep 24 13:24:22 ubuntu-202504-36599 kernel: typec_partner_register_altmode+0xe/0x20 [typec]
Sep 24 13:24:22 ubuntu-202504-36599 kernel: ucsi_register_altmode.constprop.0+0x30e/0x390 [typec_ucsi]
Sep 24 13:24:22 ubuntu-202504-36599 kernel: ucsi_register_altmodes+0x162/0x250 [typec_ucsi]
Sep 24 13:24:22 ubuntu-202504-36599 kernel: ucsi_check_altmodes+0x19/0xb0 [typec_ucsi]
Sep 24 13:24:22 ubuntu-202504-36599 kernel: ucsi_poll_worker+0x3d/0xf0 [typec_ucsi]
Sep 24 13:24:22 ubuntu-202504-36599 kernel: process_one_work+0x178/0x3d0
Sep 24 13:24:22 ubuntu-202504-36599 kernel: worker_thread+0x2de/0x410
Sep 24 13:24:22 ubuntu-202504-36599 kernel: ? __pfx_worker_thread+0x10/0x10
Sep 24 13:24:22 ubuntu-202504-36599 kernel: kthread+0xfb/0x230
Sep 24 13:24:22 ubuntu-202504-36599 kernel: ? __pfx_kthread+0x10/0x10
Sep 24 13:24:22 ubuntu-202504-36599 kernel: ret_from_fork+0x44/0x70
Sep 24 13:24:22 ubuntu-202504-36599 kernel: ? __pfx_kthread+0x10/0x10
Sep 24 13:24:22 ubuntu-202504-36599 kernel: ret_from_fork_asm+0x1a/0x30
Sep 24 13:24:22 ubuntu-202504-36599 kernel: </TASK>
Sep 24 13:24:22 ubuntu-202504-36599 kernel: typec-thunderbolt port0-partner.1: failed to create symlinks
Sep 24 13:24:22 ubuntu-202504-36599 kernel: typec-thunderbolt port0-partner.1: probe with driver typec-thunderbolt failed with error -17

[Fix]
The patch ease the call trace and only shows the firmware bug warning in the log
https://lkml.org/lkml/2025/10/16/154
v3 - https://lore.kernel.org/lkml/20251224070022.4082182-1-acelan.kao@canonical.com/

[Test]
Boot up the machine which shows the same call trace after booted up, the call trace should be replaced by something like this
   ucsi_acpi USBC000:00: con0: Firmware bug: duplicate partner altmode SVID 0x8087 at offset 1, ignoring. Please update your system firmware.

[Where problems could occur]
It doesn't affect functionalities, just detect the duplicated modes and skip it.

Chia-Lin Kao (AceLan) (3):
  usb: typec: ucsi: Detect and skip duplicate altmodes from buggy
    firmware
  usb: typec: ucsi: Add duplicate detection to nvidia registration path
  usb: typec: ucsi: yoga_c630: Remove redundant duplicate altmode
    handling

 drivers/usb/typec/ucsi/ucsi.c           | 102 +++++++++++++++++++++---
 drivers/usb/typec/ucsi/ucsi_yoga_c630.c |  23 ------
 2 files changed, 92 insertions(+), 33 deletions(-)

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2.43.0