[PATCH net-next v3 0/2] net: sfp: quirk support for XGS-PON ONT sticks with unclean EEPROMs

[Martino Dell'Ambrogio]

Some clone XGS-PON ONT sticks return EEPROM reads where the vendor PN
field contains non-printable garbage past the legitimate string instead
of the SFF-8472 mandated space padding. sfp_strlen() then can't trim
the field, the exact-length check in sfp_match() rejects the quirk
entry before the string comparison runs, and the quirk silently never
applies - so the kernel honors the module's spurious TX_FAULT and
eventually disables it.

Patch 1 adds an opt-in part-prefix-matching flag to the quirk table so
such modules can still be matched; the vendor name is always matched
exactly and existing entries behave as before. Patch 2 adds two ONT
stick entries wired to the existing potron fixup: the "OEM"
XGSPONST2001, which needs the prefix matching (it returns trailing
garbage in the PN field on cold power-up reads), and the Fiberstore
XGS-SFP-ONT-MACI, whose PN field is fully occupied by the truncated
product name and matches exactly.

Both quirks are in production use on a Bananapi BPI-R4 (MT7988A)
router on an XGS-PON uplink, backported onto 6.12.

v3, addressing Jakub's review [1][2]:
 - prefix matching is now scoped to the part field only; the vendor
   name comparison is always exact
 - the FS XGS-SFP-ONT-MACI entry is back to plain SFP_QUIRK_F: its PN
   field carries the full 16-character truncated product name, so
   prefix matching bought it nothing
 - commit messages reworded accordingly; patch 1 now describes the
   mechanism only
 - dropped the Reviewed-by tags given the functional changes

[1] https://lore.kernel.org/netdev/20260811001427.1036657-1-kuba@xxxxxxxxxx/
[2] https://lore.kernel.org/netdev/20260811001429.1036686-1-kuba@xxxxxxxxxx/

v2 (repost + checkpatch fix): https://lore.kernel.org/netdev/20260806074308.1996917-1-tillo@xxxxxxxx/
v1: https://lore.kernel.org/netdev/20260705185440.136496-1-tillo@xxxxxxxx/

Martino Dell'Ambrogio (2):
  net: sfp: allow prefix matching in quirk lookup
  net: sfp: add quirks for OEM XGSPONST2001 and FS XGS-SFP-ONT-MACI

 drivers/net/phy/sfp.c | 38 +++++++++++++++++++++++++++++++++-----
 drivers/net/phy/sfp.h |  1 +
 2 files changed, 34 insertions(+), 5 deletions(-)


base-commit: ac155a26750a595703e7dadff84735456d75a479
-- 
2.47.3