[PATCH net-next 2/2] net: sfp: add quirks for OEM XGSPONST2001 and FS XGS-SFP-ONT-MACI

[Martino Dell'Ambrogio <tillo@tillo.ch>]

Cheap XGS-PON ONT sticks identifying as vendor "OEM", PN "XGSPONST2001"
have broken TX_FAULT and LOS indicators (driven by the ONU serial
passthrough wires) and need a longer T_START_UP than the SFF-8472
default. The Fiberstore XGS-SFP-ONT-MACI MAC-mode ONT stick has the
same ONT-class TX_FAULT/LOS wiring and startup behaviour. Apply the
existing sfp_fixup_potron handler to both, which masks both signals
and bumps T_START_UP to T_START_UP_BAD_GPON.

Both modules fail to space-pad the EEPROM vendor PN field past the
legitimate string as SFF-8472 mandates (the XGSPONST2001 fills it with
non-printable garbage), which defeats exact-length matching:
sfp_strlen() cannot trim the field, so a plain SFP_QUIRK_F entry would
silently never apply and the kernel would honor the spurious TX_FAULT
and eventually disable the module. Match both entries as prefixes
using SFP_QUIRK_F_PREFIX.

Signed-off-by: Martino Dell'Ambrogio <tillo@tillo.ch>
---
 drivers/net/phy/sfp.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index e7ba642..eae0699 100644
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -555,6 +555,13 @@ static const struct sfp_quirk sfp_quirks[] = {
 	SFP_QUIRK("FS", "GPON-ONU-34-20BI", sfp_quirk_2500basex,
 		  sfp_fixup_ignore_tx_fault),
 
+	// Fiberstore XGS-SFP-ONT-MACI is a MAC-mode XGS-PON ONT stick with
+	// ONT-class serial-passthrough TX_FAULT/LOS wiring and slow startup;
+	// mask both signals and extend T_START_UP via the potron fixup. The
+	// EEPROM vendor PN field is not space-padded past the legitimate
+	// string, so match it as a prefix.
+	SFP_QUIRK_F_PREFIX("FS", "XGS-SFP-ONT-MACI", sfp_fixup_potron),
+
 	SFP_QUIRK_F("HALNy", "HL-GSFP", sfp_fixup_halny_gsfp),
 
 	SFP_QUIRK_F("H-COM", "SPP425H-GAB4", sfp_fixup_potron),
@@ -612,6 +619,14 @@ static const struct sfp_quirk sfp_quirks[] = {
 	SFP_QUIRK_S("OEM", "SFP-2.5G-LH20-A", sfp_quirk_2500basex),
 	SFP_QUIRK_F("OEM", "RTSFP-10", sfp_fixup_rollball_cc),
 	SFP_QUIRK_F("OEM", "RTSFP-10G", sfp_fixup_rollball_cc),
+
+	// OEM XGSPONST2001 is an XGS-PON ONT stick with broken TX_FAULT and
+	// LOS indicators and slow startup, just like potron. The EEPROM
+	// vendor PN field is filled with non-printable garbage past the
+	// legitimate string instead of space padding, so match it as a
+	// prefix.
+	SFP_QUIRK_F_PREFIX("OEM", "XGSPONST2001", sfp_fixup_potron),
+
 	SFP_QUIRK_F("Turris", "RTSFP-2.5G", sfp_fixup_rollball),
 	SFP_QUIRK_F("Turris", "RTSFP-10", sfp_fixup_rollball),
 	SFP_QUIRK_F("Turris", "RTSFP-10G", sfp_fixup_rollball),
-- 
2.47.3