netdev - [PATCH net-next] net: sfp: VSOL V2801F / CarlitoxxPro CPGOS03-0490 v2.0 workaround

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <E1khJlv-0003Jq-ET@rmk-PC.armlinux.org.uk>
Date:   Mon, 23 Nov 2020 21:53:19 +0000
From:   Russell King <rmk+kernel@...linux.org.uk>
To:     Andrew Lunn <andrew@...n.ch>,
        Heiner Kallweit <hkallweit1@...il.com>
Cc:     "David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org,
        Jakub Kicinski <kuba@...nel.org>
Subject: [PATCH net-next] net: sfp: VSOL V2801F / CarlitoxxPro CPGOS03-0490
 v2.0 workaround

Add a workaround for the VSOL V2801F / CarlitoxxPro CPGOS03-0490 v2.0
GPON module which the manufacturer states needs single byte I2C reads
to the EEPROM.

Reported-by: Thomas Schreiber <tschreibe@...il.com>
Tested-by: Thomas Schreiber <tschreibe@...il.com>
Signed-off-by: Russell King <rmk+kernel@...linux.org.uk>
---
 drivers/net/phy/sfp.c | 45 ++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 40 insertions(+), 5 deletions(-)

diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index debf91412a72..1e347afa951e 100644
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -219,6 +219,7 @@ struct sfp {
 	struct sfp_bus *sfp_bus;
 	struct phy_device *mod_phy;
 	const struct sff_data *type;
+	size_t i2c_block_size;
 	u32 max_power_mW;
 
 	unsigned int (*get_state)(struct sfp *);
@@ -335,10 +336,19 @@ static int sfp_i2c_read(struct sfp *sfp, bool a2, u8 dev_addr, void *buf,
 			size_t len)
 {
 	struct i2c_msg msgs[2];
-	u8 bus_addr = a2 ? 0x51 : 0x50;
+	size_t block_size;
 	size_t this_len;
+	u8 bus_addr;
 	int ret;
 
+	if (a2) {
+		block_size = 16;
+		bus_addr = 0x51;
+	} else {
+		block_size = sfp->i2c_block_size;
+		bus_addr = 0x50;
+	}
+
 	msgs[0].addr = bus_addr;
 	msgs[0].flags = 0;
 	msgs[0].len = 1;
@@ -350,8 +360,8 @@ static int sfp_i2c_read(struct sfp *sfp, bool a2, u8 dev_addr, void *buf,
 
 	while (len) {
 		this_len = len;
-		if (this_len > 16)
-			this_len = 16;
+		if (this_len > sfp->i2c_block_size)
+			this_len = sfp->i2c_block_size;
 
 		msgs[1].len = this_len;
 
@@ -1673,14 +1683,20 @@ static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
 	u8 check;
 	int ret;
 
-	ret = sfp_read(sfp, false, 0, &id, sizeof(id));
+	/* Some modules (CarlitoxxPro CPGOS03-0490) do not support multibyte
+	 * reads from the EEPROM, so start by reading the base identifying
+	 * information one byte at a time.
+	 */
+	sfp->i2c_block_size = 1;
+
+	ret = sfp_read(sfp, false, 0, &id.base, sizeof(id.base));
 	if (ret < 0) {
 		if (report)
 			dev_err(sfp->dev, "failed to read EEPROM: %d\n", ret);
 		return -EAGAIN;
 	}
 
-	if (ret != sizeof(id)) {
+	if (ret != sizeof(id.base)) {
 		dev_err(sfp->dev, "EEPROM short read: %d\n", ret);
 		return -EAGAIN;
 	}
@@ -1719,6 +1735,25 @@ static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
 		}
 	}
 
+	/* Some modules (Nokia 3FE46541AA) lock up if byte 0x51 is read as a
+	 * single read. Switch back to reading 16 byte blocks unless we have
+	 * a CarlitoxxPro module (rebranded VSOL V2801F).
+	 */
+	if (memcmp(id.base.vendor_name, "VSOL            ", 16))
+		sfp->i2c_block_size = 16;
+
+	ret = sfp_read(sfp, false, SFP_CC_BASE + 1, &id.ext, sizeof(id.ext));
+	if (ret < 0) {
+		if (report)
+			dev_err(sfp->dev, "failed to read EEPROM: %d\n", ret);
+		return -EAGAIN;
+	}
+
+	if (ret != sizeof(id.ext)) {
+		dev_err(sfp->dev, "EEPROM short read: %d\n", ret);
+		return -EAGAIN;
+	}
+
 	check = sfp_check(&id.ext, sizeof(id.ext) - 1);
 	if (check != id.ext.cc_ext) {
 		if (cotsworks) {
-- 
2.20.1