Subject: [PATCH v4 2/2] net: sfp: add mode quirk for GPON module Ubiquiti U-Fiber Instant

From: Pali Rohár <[email-masked]>
Date: Mon, 25 Jan 2021 16:02:28 +0100

The Ubiquiti U-Fiber Instant SFP GPON module has nonsensical information
stored in its EEPROM. It claims to support all transceiver types including
10G Ethernet. Clear all claimed modes and set only 1000baseX_Full, which is
the only one supported.

This module has also phys_id set to SFF, and the SFP subsystem currently
does not allow to use SFP modules detected as SFFs. Add exception for this
module so it can be detected as supported.

This change finally allows to detect and use SFP GPON module Ubiquiti
U-Fiber Instant on Linux system.

EEPROM content of this SFP module is (where XX is serial number):

00: 02 04 0b ff ff ff ff ff ff ff ff 03 0c 00 14 c8    ???........??.??
10: 00 00 00 00 55 42 4e 54 20 20 20 20 20 20 20 20    ....UBNT
20: 20 20 20 20 00 18 e8 29 55 46 2d 49 4e 53 54 41        .??)UF-INSTA
30: 4e 54 20 20 20 20 20 20 34 20 20 20 05 1e 00 36    NT      4   ??.6
40: 00 06 00 00 55 42 4e 54 XX XX XX XX XX XX XX XX    .?..UBNTXXXXXXXX
50: 20 20 20 20 31 34 30 31 32 33 20 20 60 80 02 41        140123  `??A

Signed-off-by: Pali Rohár <[email-masked]>

---
Changes in v4:
* Rewritten the commit message by Marek's suggestion

Changes in v3:
* no change

Changes in v2:
* add this module also into sfp_module_supported() function
---
 drivers/net/phy/sfp-bus.c | 15 +++++++++++++++
 drivers/net/phy/sfp.c     | 17 +++++++++++++++--
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/sfp-bus.c b/drivers/net/phy/sfp-bus.c
index 20b91f5dfc6e..4cf874fb5c5b 100644
--- a/drivers/net/phy/sfp-bus.c
+++ b/drivers/net/phy/sfp-bus.c
@@ -44,6 +44,17 @@ static void sfp_quirk_2500basex(const struct sfp_eeprom_id *id,
 	phylink_set(modes, 2500baseX_Full);
 }
 
+static void sfp_quirk_ubnt_uf_instant(const struct sfp_eeprom_id *id,
+				      unsigned long *modes)
+{
+	/* Ubiquiti U-Fiber Instant module claims that support all transceiver
+	 * types including 10G Ethernet which is not truth. So clear all claimed
+	 * modes and set only one mode which module supports: 1000baseX_Full.
+	 */
+	phylink_zero(modes);
+	phylink_set(modes, 1000baseX_Full);
+}
+
 static const struct sfp_quirk sfp_quirks[] = {
 	{
 		// Alcatel Lucent G-010S-P can operate at 2500base-X, but
@@ -63,6 +74,10 @@ static const struct sfp_quirk sfp_quirks[] = {
 		.vendor = "HUAWEI",
 		.part = "MA5671A",
 		.modes = sfp_quirk_2500basex,
+	}, {
+		.vendor = "UBNT",
+		.part = "UF-INSTANT",
+		.modes = sfp_quirk_ubnt_uf_instant,
 	},
 };
 
diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index f2b5e467a800..7a680b5177f5 100644
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -273,8 +273,21 @@ static const struct sff_data sff_data = {
 
 static bool sfp_module_supported(const struct sfp_eeprom_id *id)
 {
-	return id->base.phys_id == SFF8024_ID_SFP &&
-	       id->base.phys_ext_id == SFP_PHYS_EXT_ID_SFP;
+	if (id->base.phys_id == SFF8024_ID_SFP &&
+	    id->base.phys_ext_id == SFP_PHYS_EXT_ID_SFP)
+		return true;
+
+	/* SFP GPON module Ubiquiti U-Fiber Instant has in its EEPROM stored
+	 * phys id SFF instead of SFP. Therefore mark this module explicitly
+	 * as supported based on vendor name and pn match.
+	 */
+	if (id->base.phys_id == SFF8024_ID_SFF_8472 &&
+	    id->base.phys_ext_id == SFP_PHYS_EXT_ID_SFP &&
+	    !memcmp(id->base.vendor_name, "UBNT            ", 16) &&
+	    !memcmp(id->base.vendor_pn, "UF-INSTANT      ", 16))
+		return true;
+
+	return false;
 }
 
 static const struct sff_data sfp_data = {
-- 
2.20.1