[PATCH net-next v5 0/2] net: pse-pd: add poll path and LED trigger support

[Carlo Szelinsky <github@szelinsky.de>]

Thanks to Kory, Oleksij, Krzysztof, Andrew and Jakub for all the
helpful feedback on earlier versions:-) I really appreciate the time
you put into reviewing this. I hope this is now the last round ;-)

This series adds poll-based event detection and LED trigger support
to the PSE core subsystem.

Patch 1 introduces the poll path independently of LED support,
so it can be tested in isolation on boards with and without IRQ
configured.

Patch 2 adds LED triggers that hook into the shared event handling
path introduced by patch 1.

Note: while reworking the poll teardown for v5, I noticed
pse_release_pis() (which kfree()s the pi[] array) runs before
disable_irq() / cancel_delayed_work_sync() in
pse_controller_unregister(). A concurrent IRQ or poll worker that
fires in that window would read through a freed pi[]. This is
pre-existing for the IRQ path (since fc0e6db30941, "Add support for
reporting events"); the v5 poll cancel inherits the same placement
for symmetry. Does it make sense that I send a separate fix that disables
both async sources before pse_release_pis() or am I wrong here?

Changes since v4:
- Rebased on top of "net: pse-pd: fix out-of-bounds bitmap access in
  pse_isr() on 32-bit" (5099807f335c, merged via net). Extended the
  same bitmap-pointer pattern to the new pse_handle_events() and
  pse_poll_worker() code paths so for_each_set_bit() does not read
  past a single unsigned long when nr_lines > BITS_PER_LONG (Jakub,
  Kory)
- Cancel the poll work explicitly in pse_controller_unregister(),
  next to the existing disable_irq() for the IRQ path, instead of
  relying on devm_add_action_or_reset() LIFO ordering. Makes the
  helper safe even when a driver registers it in the standard order
  (helper before devm_pse_controller_register()) (Jakub)
- struct pse_pi_led_triggers no longer wrapped in
  #if IS_ENABLED(CONFIG_LEDS_TRIGGERS); only the function bodies
  remain ifdef'd, so reference sites no longer need their own
  ifdefs (Jakub)
- Added .activate callbacks for both LED triggers. Without these,
  an LED bound to a trigger after pse_controller_register() (e.g.
  via sysfs) would stay dark until the next hardware event toggled
  state (Jakub)
- Run the post-registration initial-state pass under pcdev->lock,
  matching pse_led_update()'s documented locking contract and
  avoiding races with concurrent regulator_enable() that share
  last_delivering / last_enabled and the hardware ops (Jakub)
- On partial pse_led_triggers_register() failure, NULL out
  pcdev->pi_led_trigs so the existing early-return guard in
  pse_led_update() short-circuits any later calls onto
  partially-registered triggers (Jakub)

Changes since v3:
- Dropped the dt-bindings poll-interval-ms patch: the poll interval
  is a driver decision, not a hardware property (Krzysztof)
- Removed of_property_read_u32() for poll-interval-ms from
  devm_pse_poll_helper(); the 500ms default is now hardcoded but
  drivers can override pcdev->poll_interval_ms before calling the
  helper
- Rebased on net-next/main

Changes since v2:
- Based on net-next/main, added net-next subject prefix
- Added --base tree information
- Added CC for devicetree list and DT maintainers
- Collected Reviewed-by from Kory Maincent on patch 1/3
- Fixed build error when CONFIG_LEDS_TRIGGERS is disabled:
  moved LED registration before list_add(), removing the
  pcdev->pi_led_trigs = NULL assignment on conditionally
  compiled struct member (reported by kernel test robot)
- Fixed use-after-free on device unbind: poll work is now
  cancelled via devm_add_action_or_reset() to ensure correct
  devres teardown ordering (poll_work cancelled before
  poll_notifs is freed)
- Used system_freezable_wq for poll worker to prevent hardware
  access during system suspend
- Added PoDL power status and admin state checks to LED triggers
  so they work for both C33 and PoDL controller types
- Used dev_name(dev) for LED trigger names to ensure uniqueness
  across multiple PSE controllers (of_node->name can be generic)
- Added initial LED state query at registration so already-active
  ports are reflected immediately
- Added pse_led_update() calls in regulator enable/disable paths
  so ethtool admin state changes are reflected in LEDs
- Moved LED trigger registration before list_add() to prevent
  race where IRQ/poll could invoke pse_led_update() on partially
  initialized triggers

Changes since v1:
- Split single patch into 3 separate patches
- Extracted pse_handle_events() and devm_pse_poll_helper() as a
  standalone poll path (patches 1-2), testable without LED code
- Added DT binding for poll-interval-ms as a separate patch
- Renamed led-poll-interval-ms to poll-interval-ms for generic use
- Fire LED triggers from the notification path rather than a
  separate poll loop

Tested on Realtek RTL9303 with HS104 PoE chip, poll path only
(without IRQ configured). Verified PD connect/disconnect notifications
and LED trigger state changes.

Link: https://lore.kernel.org/all/20260410124428.809943-1-github@szelinsky.de/
Link: https://lore.kernel.org/all/20260329153124.2823980-1-github@szelinsky.de/
Link: https://lore.kernel.org/all/20260323201225.1836561-1-github@szelinsky.de/

Carlo Szelinsky (2):
  net: pse-pd: add devm_pse_poll_helper()
  net: pse-pd: add LED trigger support via notification path

 drivers/net/pse-pd/pse_core.c | 355 +++++++++++++++++++++++++++++++---
 include/linux/pse-pd/pse.h    |  32 +++
 2 files changed, 356 insertions(+), 31 deletions(-)


base-commit: 09942ddedcb960f9e78fd817ec33f501d1040c5b
--
2.43.0