[PATCH v5 0/3] driver core: add enumeration failure uevent helper
From: Akshay Gujar
Date: Wed Jul 15 2026 - 07:48:56 EST
Hotpluggable buses can detect that a device is physically present, but
enumeration may still fail early due to protocol-level errors. Today,
such failures are only reported via kernel log messages, with no
structured userspace notification.
This series introduces a small, generic helper in the driver core that
emits a KOBJ_CHANGE uevent when enumeration fails, and wires it into the
USB hub enumeration failure path as an initial user.
The USB change is intentionally minimal and serves as an initial user of
the generic helper. Other subsystems may use the helper independently if
needed.
---
Changes in v5:
- Update ABI doc (date, version)
Changes in v4:
- Remove duplicate kerneldoc from device.h; keep only in core.c
- Clarify @dev description
- Update ABI doc (date)
Changes in v3:
- Rename 'parent' to 'dev'
- Remove 'id_name'; derive identifier via dev_name()
- Improve comments and commit messages
- Add kernel-doc in device.h
- Update ABI doc (date, version, example)
- usb: hub: pass &port_dev->dev directly
Changes in v2:
- Move helper from USB-specific code into driver core
- Add ABI documentation
- Split into a 3-patch series
v4: https://lore.kernel.org/all/2026071012-hesitancy-doornail-3dab@gregkh/
v3: https://lore.kernel.org/all/0b39693a-d8b0-4c95-97ee-07b3882c4b6a@xxxxxxxxxxxxxxxxxxx/
v2: https://lore.kernel.org/all/2026010726-grimy-variably-b10e@gregkh/
v1: https://lore.kernel.org/all/2025022131-silo-impeach-3f24@gregkh/
Akshay Gujar (3):
driver core: add device_enumeration_failure_notify() helper
Documentation: ABI: document DEVICE_ENUMERATION_FAILURE uevent
usb: hub: send enumeration failure uevent
Documentation/ABI/testing/sysfs-uevent | 25 +++++++++++++++
drivers/base/core.c | 44 ++++++++++++++++++++++++++
drivers/usb/core/hub.c | 4 ++-
include/linux/device.h | 2 ++
4 files changed, 74 insertions(+), 1 deletion(-)
base-commit: 0f26556c5eeea62cc934fa8938b148aa5844a6b6
--
2.19.0