[PATCH net v4 0/2] net: ravb: fix PTP clock lifetime

[Xuanqiang Luo <xuanqiang.luo@linux.dev>]

From: Xuanqiang Luo <luoxuanqiang@kylinos.cn>

This series fixes RAVB PTP clock lifetime handling. It reports a cached PHC
index without accessing the clock pointer and drains PTP interrupts before
unregistering the clock.

Patch 1 caches the PHC index and handles registration failures.

Patch 2 detaches the clock with xchg() and drains the PTP IRQs before
unregistering it.

---
Changes:
v4:
  - Rebase onto Linux 7.2-rc7.
  Patch 1:
  - Cache the PHC index separately instead of locking clock access.
    (Vadim Fedorenko)
  - Reword the subject and update the commit message for the cached PHC
    index approach.
  - Add Vadim Fedorenko's Reviewed-by tag.
  Patch 2:
  - Replace priv->lock serialization with PTP interrupt disabling and IRQ
    draining before unregistering the clock. (Vadim Fedorenko)
  - Use READ_ONCE() and WRITE_ONCE() for lockless clock pointer access and
    xchg() to detach the clock atomically.
  - Track the error and management IRQs and synchronize all IRQs that can
    invoke the PTP handler.
  - Update the commit message to describe the interrupt handler race and
    the new teardown sequence.

v3: https://lore.kernel.org/all/20260806095126.57803-1-xuanqiang.luo@linux.dev/
  Patch 1:
  - Omit Niklas Söderlund's Reviewed-by tag because the implementation he
    reviewed has changed.
  - Describe the NULL pointer dereference before the first open as the most
    likely failure mode in the commit message. (Jakub Kicinski, Sashiko)
  - Normalize PTP clock registration failures to NULL.
    (Jakub Kicinski, Sashiko)
  - Keep hardware timestamping capabilities independent of PHC
    availability. (Jakub Kicinski, Sashiko)
  Patch 2 (new):
  - Serialize PTP clock publication and access with priv->lock, and detach
    the clock before unregistering it. (Jakub Kicinski, Sashiko)

v2: https://lore.kernel.org/all/20260802090750.116215-1-xuanqiang.luo@linux.dev/
  - Only advertise hardware timestamping support when a PHC is available
    (Niklas Söderlund).

v1: https://lore.kernel.org/all/20260731063254.71260-1-xuanqiang.luo@linux.dev/

Xuanqiang Luo (2):
  net: ravb: avoid dereferencing an invalid PTP clock
  net: ravb: serialize PTP clock teardown

 drivers/net/ethernet/renesas/ravb.h      |  3 ++
 drivers/net/ethernet/renesas/ravb_main.c |  9 +++--
 drivers/net/ethernet/renesas/ravb_ptp.c  | 44 ++++++++++++++++++++----
 3 files changed, 47 insertions(+), 9 deletions(-)


base-commit: db2ddb87143519e20a95aa36c60b36107b736a58
-- 
2.43.0