[PATCH net-next 0/9] ptp: ocp: TAP CPLD follow-up fixes

[Sagi Maimon <maimon.sagi@gmail.com>]

Follow-up to the automated review of the TAP CPLD series, as Jakub asked
for on the v15 posting.  Nothing here changes what the driver puts on the
I2C wire: the ISP command sequence, the frame contents and the arbitration
timing are untouched.

Patches 1-5 answer the review of 3/4.  Patch 1 is the one with real
runtime behaviour to it: the CPLD identification read shared
ptp_ocp_sync_work() with the 1 Hz in-sync poller, and a claim that has to
wait for the MicroBlaze can occupy that work item for seconds, delaying
the dpll change notification and stalling the cancel_delayed_work_sync()
that ptp_ocp_remove() - also the .shutdown handler - starts with.  Patch 2
is the point the review rated High: the hand-back can fail, and the driver
would then cache and publish whatever answered on the TMC segment as the
board serial and id.

Patches 6-9 answer the review of 4/4.  Three of them remove ways the
driver could report success, or keep reporting an identity, when the part
had not done what was asked:

 - a latched FAILED made every later flash of a part that had failed once
   return -EIO at the enable step, before reaching the ERASE and REFRESH
   that would recover it (patch 8);
 - the post-REFRESH predicate was already satisfied by the state SET_DONE
   leaves behind, so a REFRESH that was ACKed but never latched passed it
   with the old image still running (patch 9);
 - the cached identity was dropped after the erase *wait* rather than
   before the erase was issued, and it dropped cpld.id too, which is the
   silicon IDCODE and cannot change (patch 7).

Patch 6 stops publishing the string "unknown" as a devlink running
version.  The review pointed out that devlink_info_version_put() invokes
its version_cb before the empty-value early-out, so an empty value still
registers the component name for devlink_flash_component_get() - which is
what a placeholder was needed for - while emitting no version attribute.

Tested on an ADVA TimeCard X1: the CPLD programs and activates as before
with the whole series applied, so the two checks that decide whether an
operation is believed - ENAB after EN_CFG_TP in patch 8, and ENAB clear
after REFRESH in patch 9 - agree with the part.  Patches 2-4 sit on the
hand-back timeout and adapter-lookup failure paths, which do not trigger
in normal operation; the hand-back measures about 670 ms against its 2 s
budget.

v15: https://lore.kernel.org/netdev/20260916153242.157171-1-sagi.maimon@adtran.com/T/#u


Sagi Maimon (9):
  ptp: ocp: move the CPLD identification read off the sync worker
  ptp: ocp: do not cache EEPROM content after a failed TMC bus hand-back
  ptp: ocp: hand the TMC bus back once on an acquire timeout
  ptp: ocp: forget a CPLD i2c adapter number that no longer resolves
  ptp: ocp: correct the CPLD bookkeeping comments and the flash progress
  ptp: ocp: report fw.cpld with an empty value until the USERCODE is
    read
  ptp: ocp: drop only the USERCODE when flashing, and drop it before
    erasing
  ptp: ocp: tolerate a latched FAILED when entering configuration mode
  ptp: ocp: confirm the CPLD really left configuration mode after
    REFRESH

 Documentation/ABI/testing/sysfs-timecard     |   8 +-
 Documentation/networking/devlink/ptp_ocp.rst |  28 ++-
 drivers/ptp/ptp_ocp.c                        | 188 +++++++++++++++----
 3 files changed, 170 insertions(+), 54 deletions(-)


base-commit: 10cfa109c880092df32e396647b4afdca9be8350
-- 
2.47.0