From 43ac680124bc57951a6d0356b41498c2324388bf Mon Sep 17 00:00:00 2001
From: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Date: Fri, 26 Aug 2022 08:43:45 +0100
Subject: [PATCH 4/6] net: sfp: add support for HALNy GPON SFP

Add a quirk for the HALNy HL-GSFP module, which appears to have an
inverted RX_LOS signal, and possibly uses TX_FAULT as an inverted
host-link status signal. As we can't be certain about the modules
use of TX_FAULT, we ignore it.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 drivers/net/phy/sfp-bus.c |  2 +-
 drivers/net/phy/sfp.c     | 29 ++++++++++++++++++++++++++---
 2 files changed, 27 insertions(+), 4 deletions(-)

--- a/drivers/net/phy/sfp-bus.c
+++ b/drivers/net/phy/sfp-bus.c
@@ -283,7 +283,7 @@ void sfp_parse_support(struct sfp_bus *b
 			phylink_set(modes, 2500baseX_Full);
 	}
 
-	if (bus->sfp_quirk)
+	if (bus->sfp_quirk && bus->sfp_quirk->modes)
 		bus->sfp_quirk->modes(id, modes);
 
 	linkmode_or(support, support, modes);
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -320,6 +320,23 @@ static void sfp_fixup_ignore_tx_fault(st
 	sfp->tx_fault_ignore = true;
 }
 
+static void sfp_fixup_inverted_los(struct sfp *sfp)
+{
+	const __be16 los_inverted = cpu_to_be16(SFP_OPTIONS_LOS_INVERTED);
+	const __be16 los_normal = cpu_to_be16(SFP_OPTIONS_LOS_NORMAL);
+
+	sfp->id.ext.options &= ~los_normal;
+	sfp->id.ext.options |= los_inverted;
+}
+
+static void sfp_fixup_halny_gsfp(struct sfp *sfp)
+{
+	/* LOS is inverted */
+	sfp_fixup_inverted_los(sfp);
+	/* TX fault might be inverted, but we don't know for certain. */
+	sfp_fixup_ignore_tx_fault(sfp);
+}
+
 static void sfp_quirk_2500basex(const struct sfp_eeprom_id *id,
 				unsigned long *modes)
 {
@@ -352,6 +369,10 @@ static const struct sfp_quirk sfp_quirks
 		.modes = sfp_quirk_2500basex,
 		.fixup = sfp_fixup_long_startup,
 	}, {
+		.vendor = "HALNy",
+		.part = "HL-GSFP",
+		.fixup = sfp_fixup_halny_gsfp,
+	}, {
 		// Huawei MA5671A can operate at 2500base-X, but report 1.2GBd
 		// NRZ in their EEPROM
 		.vendor = "HUAWEI",
@@ -368,16 +389,18 @@ static const struct sfp_quirk sfp_quirks
 		.vendor = "UBNT",
 		.part = "UF-INSTANT",
 		.modes = sfp_quirk_ubnt_uf_instant,
-	},
+	}
 };
 
 static size_t sfp_strlen(const char *str, size_t maxlen)
 {
 	size_t size, i;
 
-	/* Trailing characters should be filled with space chars */
+	/* Trailing characters should be filled with space chars, but
+	 * some manufacturers can't read SFF-8472 and use NUL.
+	 */
 	for (i = 0, size = 0; i < maxlen; i++)
-		if (str[i] != ' ')
+		if (str[i] != ' ' && str[i] != '\0')
 			size = i + 1;
 
 	return size;