--- /dev/null
+From 6bf8085274a416afa6dcdcc348ad293827bbbdb2 Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Mon, 25 Jan 2021 16:02:27 +0100
+Subject: net: sfp: add workaround for Realtek RTL8672 and RTL9601C chips
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Pali Rohár <pali@kernel.org>
+
+[ Upstream commit 426c6cbc409cbda9ab1a9dbf15d3c2ef947eb8c1 ]
+
+The workaround for VSOL V2801F brand based GPON SFP modules added in commit
+0d035bed2a4a ("net: sfp: VSOL V2801F / CarlitoxxPro CPGOS03-0490 v2.0
+workaround") works only for IDs added explicitly to the list. Since there
+are rebranded modules where OEM vendors put different strings into the
+vendor name field, we cannot base workaround on IDs only.
+
+Moreover the issue which the above mentioned commit tried to work around is
+generic not only to VSOL based modules, but rather to all GPON modules
+based on Realtek RTL8672 and RTL9601C chips.
+
+These include at least the following GPON modules:
+* V-SOL V2801F
+* C-Data FD511GX-RM0
+* OPTON GP801R
+* BAUDCOM BD-1234-SFM
+* CPGOS03-0490 v2.0
+* Ubiquiti U-Fiber Instant
+* EXOT EGS1
+
+These Realtek chips have broken EEPROM emulator which for N-byte read
+operation returns just the first byte of EEPROM data, followed by N-1
+zeros.
+
+Introduce a new function, sfp_id_needs_byte_io(), which detects SFP modules
+with broken EEPROM emulator based on N-1 zeros and switch to 1 byte EEPROM
+reading operation.
+
+Function sfp_i2c_read() now always uses single byte reading when it is
+required and when function sfp_hwmon_probe() detects single byte access,
+it disables registration of hwmon device, because in this case we cannot
+reliably and atomically read 2 bytes as is required by the standard for
+retrieving values from diagnostic area.
+
+(These Realtek chips are broken in a way that violates SFP standards for
+diagnostic interface. Kernel in this case simply cannot do anything less
+of skipping registration of the hwmon interface.)
+
+This patch fixes reading of EEPROM content from SFP modules based on
+Realtek RTL8672 and RTL9601C chips. Diagnostic interface of EEPROM stays
+broken and cannot be fixed.
+
+Fixes: 0d035bed2a4a ("net: sfp: VSOL V2801F / CarlitoxxPro CPGOS03-0490 v2.0 workaround")
+Co-developed-by: Russell King <rmk+kernel@armlinux.org.uk>
+Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
+Signed-off-by: Pali Rohár <pali@kernel.org>
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ drivers/net/phy/sfp.c | 100 ++++++++++++++++++++++++++++--------------
+ 1 file changed, 67 insertions(+), 33 deletions(-)
+
+diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
+index 804295ad8a04..7a680b5177f5 100644
+--- a/drivers/net/phy/sfp.c
++++ b/drivers/net/phy/sfp.c
+@@ -349,19 +349,11 @@ static int sfp_i2c_read(struct sfp *sfp, bool a2, u8 dev_addr, void *buf,
+ size_t len)
+ {
+ struct i2c_msg msgs[2];
+- size_t block_size;
++ u8 bus_addr = a2 ? 0x51 : 0x50;
++ size_t block_size = sfp->i2c_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;
+@@ -1295,6 +1287,20 @@ static void sfp_hwmon_probe(struct work_struct *work)
+ struct sfp *sfp = container_of(work, struct sfp, hwmon_probe.work);
+ int err, i;
+
++ /* hwmon interface needs to access 16bit registers in atomic way to
++ * guarantee coherency of the diagnostic monitoring data. If it is not
++ * possible to guarantee coherency because EEPROM is broken in such way
++ * that does not support atomic 16bit read operation then we have to
++ * skip registration of hwmon device.
++ */
++ if (sfp->i2c_block_size < 2) {
++ dev_info(sfp->dev,
++ "skipping hwmon device registration due to broken EEPROM\n");
++ dev_info(sfp->dev,
++ "diagnostic EEPROM area cannot be read atomically to guarantee data coherency\n");
++ return;
++ }
++
+ err = sfp_read(sfp, true, 0, &sfp->diag, sizeof(sfp->diag));
+ if (err < 0) {
+ if (sfp->hwmon_tries--) {
+@@ -1655,26 +1661,30 @@ static int sfp_sm_mod_hpower(struct sfp *sfp, bool enable)
+ return 0;
+ }
+
+-/* 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). Even more annoyingly,
+- * some VSOL V2801F have the vendor name changed to OEM.
++/* GPON modules based on Realtek RTL8672 and RTL9601C chips (e.g. V-SOL
++ * V2801F, CarlitoxxPro CPGOS03-0490, Ubiquiti U-Fiber Instant, ...) do
++ * not support multibyte reads from the EEPROM. Each multi-byte read
++ * operation returns just one byte of EEPROM followed by zeros. There is
++ * no way to identify which modules are using Realtek RTL8672 and RTL9601C
++ * chips. Moreover every OEM of V-SOL V2801F module puts its own vendor
++ * name and vendor id into EEPROM, so there is even no way to detect if
++ * module is V-SOL V2801F. Therefore check for those zeros in the read
++ * data and then based on check switch to reading EEPROM to one byte
++ * at a time.
+ */
+-static int sfp_quirk_i2c_block_size(const struct sfp_eeprom_base *base)
++static bool sfp_id_needs_byte_io(struct sfp *sfp, void *buf, size_t len)
+ {
+- if (!memcmp(base->vendor_name, "VSOL ", 16))
+- return 1;
+- if (!memcmp(base->vendor_name, "OEM ", 16) &&
+- !memcmp(base->vendor_pn, "V2801F ", 16))
+- return 1;
++ size_t i, block_size = sfp->i2c_block_size;
+
+- /* Some modules can't cope with long reads */
+- return 16;
+-}
++ /* Already using byte IO */
++ if (block_size == 1)
++ return false;
+
+-static void sfp_quirks_base(struct sfp *sfp, const struct sfp_eeprom_base *base)
+-{
+- sfp->i2c_block_size = sfp_quirk_i2c_block_size(base);
++ for (i = 1; i < len; i += block_size) {
++ if (memchr_inv(buf + i, '\0', min(block_size - 1, len - i)))
++ return false;
++ }
++ return true;
+ }
+
+ static int sfp_cotsworks_fixup_check(struct sfp *sfp, struct sfp_eeprom_id *id)
+@@ -1718,11 +1728,11 @@ static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
+ u8 check;
+ int ret;
+
+- /* 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.
++ /* Some SFP modules and also some Linux I2C drivers do not like reads
++ * longer than 16 bytes, so read the EEPROM in chunks of 16 bytes at
++ * a time.
+ */
+- sfp->i2c_block_size = 1;
++ sfp->i2c_block_size = 16;
+
+ ret = sfp_read(sfp, false, 0, &id.base, sizeof(id.base));
+ if (ret < 0) {
+@@ -1736,6 +1746,33 @@ static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
+ return -EAGAIN;
+ }
+
++ /* Some SFP modules (e.g. Nokia 3FE46541AA) lock up if read from
++ * address 0x51 is just one byte at a time. Also SFF-8472 requires
++ * that EEPROM supports atomic 16bit read operation for diagnostic
++ * fields, so do not switch to one byte reading at a time unless it
++ * is really required and we have no other option.
++ */
++ if (sfp_id_needs_byte_io(sfp, &id.base, sizeof(id.base))) {
++ dev_info(sfp->dev,
++ "Detected broken RTL8672/RTL9601C emulated EEPROM\n");
++ dev_info(sfp->dev,
++ "Switching to reading EEPROM to one byte at a time\n");
++ 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.base)) {
++ dev_err(sfp->dev, "EEPROM short read: %d\n", ret);
++ return -EAGAIN;
++ }
++ }
++
+ /* Cotsworks do not seem to update the checksums when they
+ * do the final programming with the final module part number,
+ * serial number and date code.
+@@ -1770,9 +1807,6 @@ static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
+ }
+ }
+
+- /* Apply any early module-specific quirks */
+- sfp_quirks_base(sfp, &id.base);
+-
+ ret = sfp_read(sfp, false, SFP_CC_BASE + 1, &id.ext, sizeof(id.ext));
+ if (ret < 0) {
+ if (report)
+--
+2.30.1
+
--- /dev/null
+From ef23f4c02cce8658f78a563126c44e4d121292f1 Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Wed, 9 Dec 2020 11:22:49 +0000
+Subject: net: sfp: VSOL V2801F / CarlitoxxPro CPGOS03-0490 v2.0 workaround
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Russell King <rmk+kernel@armlinux.org.uk>
+
+[ Upstream commit 0d035bed2a4a6c4878518749348be61bf082d12a ]
+
+Add a workaround for the detection of VSOL V2801F / CarlitoxxPro
+CPGOS03-0490 v2.0 GPON module which CarlitoxxPro states needs single
+byte I2C reads to the EEPROM.
+
+Pali Rohár reports that he also has a CarlitoxxPro-based V2801F module,
+which reports a manufacturer of "OEM". This manufacturer can't be
+matched as it appears in many different modules, so also match the part
+number too.
+
+Reported-by: Thomas Schreiber <tschreibe@gmail.com>
+Reported-by: Pali Rohár <pali@kernel.org>
+Tested-by: Pali Rohár <pali@kernel.org>
+Reviewed-by: Andrew Lunn <andrew@lunn.ch>
+Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ drivers/net/phy/sfp.c | 63 +++++++++++++++++++++++++++++++++++++++----
+ 1 file changed, 58 insertions(+), 5 deletions(-)
+
+diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
+index d8a809cf20c1..804295ad8a04 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 *);
+@@ -348,10 +349,19 @@ 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;
+@@ -363,8 +373,8 @@ 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 > block_size)
++ this_len = block_size;
+
+ msgs[1].len = this_len;
+
+@@ -1645,6 +1655,28 @@ static int sfp_sm_mod_hpower(struct sfp *sfp, bool enable)
+ return 0;
+ }
+
++/* 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). Even more annoyingly,
++ * some VSOL V2801F have the vendor name changed to OEM.
++ */
++static int sfp_quirk_i2c_block_size(const struct sfp_eeprom_base *base)
++{
++ if (!memcmp(base->vendor_name, "VSOL ", 16))
++ return 1;
++ if (!memcmp(base->vendor_name, "OEM ", 16) &&
++ !memcmp(base->vendor_pn, "V2801F ", 16))
++ return 1;
++
++ /* Some modules can't cope with long reads */
++ return 16;
++}
++
++static void sfp_quirks_base(struct sfp *sfp, const struct sfp_eeprom_base *base)
++{
++ sfp->i2c_block_size = sfp_quirk_i2c_block_size(base);
++}
++
+ static int sfp_cotsworks_fixup_check(struct sfp *sfp, struct sfp_eeprom_id *id)
+ {
+ u8 check;
+@@ -1686,14 +1718,20 @@ 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;
+ }
+@@ -1732,6 +1770,21 @@ static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
+ }
+ }
+
++ /* Apply any early module-specific quirks */
++ sfp_quirks_base(sfp, &id.base);
++
++ 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) {
+--
+2.30.1
+
projects / thirdparty / kernel / stable-queue.git / commitdiff
