[PATCH net-next v3 0/4] net: dsa: mxl862xx: support firmware update

[Daniel Golle <daniel@makrotopia.org>]

The firmware of MxL862xx managed Ethernet switches can be updated
in-system via the same MDIO bus which is also used to manage the
switch. Wire up the devlink flash_update operation for DSA drivers
and implement firmware update and version reporting in the mxl862xx
driver.

Changes since v2 [2]:
 - validate the firmware image, including both CRCs, before taking
   down any ports, so that a malformed file is rejected without
   disturbing the running switch and without the needless flash and
   reprobe cycle it previously triggered
 - reject images whose declared payload sizes overflow when summed
   (check_add_overflow) or sum up to zero; the latter previously
   erased the flash without writing anything back
 - allocate the reprobe work item and take the module and device
   references before starting the update, so scheduling the reprobe
   can no longer fail after the switch has been pushed into MCUboot
 - prevent the stats poll work from being re-armed and cancel the
   CRC error work before starting the transfer
 - check the host-blocking flags in mxl862xx_api_wrap() under the
   MDIO bus lock to close the race window where an API command
   which had already passed the check could reach the bus after the
   switch rebooted into MCUboot
 - check the return value of SB PDI data word writes so a failed
   MDIO transaction aborts the transfer instead of being noticed
   only through a corrupted image
 - report a per-model chip name (e.g. "MaxLinear MxL86252") as the
   devlink "asic.id" fixed version instead of the devicetree
   compatible string, whose comma is awkward for userspace
   consumers such as fwupd (see discussion on v2 patch 3)
 - report the canonical null version "0.0.0" instead of
   "mcuboot-rescue" as the running firmware version in rescue mode,
   so that version-comparing update tools like fwupd treat every
   available release as an upgrade and offer it for recovery

Changes since RFC [1]:
 - detect a switch stuck in MCUboot rescue mode at probe, register
   the switch without any ports and report "mcuboot-rescue" as the
   running firmware version, so devlink flash can recover from a
   failed or interrupted update (Andrew Lunn)
 - clarify in the commit message of patch 2 that the per-transaction
   MDIO bus locking is about other, non-switch devices on the same
   MDIO bus (Andrew Lunn)
 - mention in the commit message of patch 3 that closing the ports
   also stops phylib from polling the switch-internal PHYs during
   the transfer (Andrew Lunn)
 - split up run-on sentence and explain the dynamically allocated
   reprobe work item instead of just pointing at iwlwifi in the
   commit message of patch 3 (Manuel Ebner)
 - use kzalloc_obj() (Manuel Ebner)
 - state the actual duration of a complete flash and reprobe cycle
   (just under a minute) in comments and the commit message, and
   clarify that the timeout values are generous upper bounds
   (Manuel Ebner)

[1] https://lore.kernel.org/all/ak0J-HgzMRea53om@makrotopia.org/
[2] https://lore.kernel.org/all/cover.1783988826.git.daniel@makrotopia.org/

Daniel Golle (4):
  net: dsa: wire flash_update devlink callback to drivers
  net: dsa: mxl862xx: add SMDIO clause-22 register access
  net: dsa: mxl862xx: add devlink flash_update and info_get
  net: dsa: mxl862xx: recover switch stuck in MCUboot rescue mode

 drivers/net/dsa/mxl862xx/Makefile           |   2 +-
 drivers/net/dsa/mxl862xx/mxl862xx-cmd.h     |   1 +
 drivers/net/dsa/mxl862xx/mxl862xx-fw.c      | 482 ++++++++++++++++++++
 drivers/net/dsa/mxl862xx/mxl862xx-fw.h      |  18 +
 drivers/net/dsa/mxl862xx/mxl862xx-host.c    |  51 +++
 drivers/net/dsa/mxl862xx/mxl862xx-host.h    |   2 +
 drivers/net/dsa/mxl862xx/mxl862xx-phylink.c |   2 +
 drivers/net/dsa/mxl862xx/mxl862xx.c         |  45 +-
 drivers/net/dsa/mxl862xx/mxl862xx.h         |   9 +
 include/net/dsa.h                           |   3 +
 net/dsa/devlink.c                           |  13 +
 11 files changed, 622 insertions(+), 6 deletions(-)
 create mode 100644 drivers/net/dsa/mxl862xx/mxl862xx-fw.c
 create mode 100644 drivers/net/dsa/mxl862xx/mxl862xx-fw.h


base-commit: ce6b4d3216b63f902bb8e9695ee6c10c83415f65
-- 
2.55.0