From 426c6cbc409cbda9ab1a9dbf15d3c2ef947eb8c1 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= Date: Mon, 25 Jan 2021 16:02:27 +0100 Subject: [PATCH 1/2] 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 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 Signed-off-by: Russell King Signed-off-by: Pali Rohár Signed-off-by: Jakub Kicinski --- 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 b2a5ed6915fa..ca68839c27ce 100644 --- a/drivers/net/phy/sfp.c +++ b/drivers/net/phy/sfp.c @@ -340,19 +340,11 @@ 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; @@ -1286,6 +1278,20 @@ 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--) { @@ -1702,26 +1708,30 @@ 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) @@ -1765,11 +1775,11 @@ 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) { @@ -1783,6 +1793,33 @@ 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. @@ -1817,9 +1854,6 @@ 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) From f0b4f847673299577c29b71d3f3acd3c313d81b7 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= Date: Mon, 25 Jan 2021 16:02:28 +0100 Subject: [PATCH 2/2] net: sfp: add mode quirk for GPON module Ubiquiti U-Fiber Instant MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Jakub Kicinski --- 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 3c67ad9951ab..3cfd773ae5f4 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 ca68839c27ce..7998acc689b7 100644 --- a/drivers/net/phy/sfp.c +++ b/drivers/net/phy/sfp.c @@ -277,8 +277,21 @@ 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 = {