From 813c2dd78618f108fdcf9cd726ea90f081ee2881 Mon Sep 17 00:00:00 2001 From: Ivan Bornyakov Date: Thu, 6 Apr 2023 16:08:32 +0300 Subject: net: sfp: initialize sfp->i2c_block_size at sfp allocation sfp->i2c_block_size is initialized at SFP module insertion in sfp_sm_mod_probe(). Because of that, if SFP module was never inserted since boot, sfp_read() call will lead to zero-length I2C read attempt, and not all I2C controllers are happy with zero-length reads. One way to issue sfp_read() on empty SFP cage is to execute ethtool -m. If SFP module was never plugged since boot, there will be a zero-length I2C read attempt. # ethtool -m xge0 i2c i2c-3: adapter quirk: no zero length (addr 0x0050, size 0, read) Cannot get Module EEPROM data: Operation not supported If SFP module was plugged then removed at least once, sfp->i2c_block_size will be initialized and ethtool -m will fail with different exit code and without I2C error # ethtool -m xge0 Cannot get Module EEPROM data: Remote I/O error Fix this by initializing sfp->i2_block_size at struct sfp allocation stage so no wild sfp_read() could issue zero-length I2C read. Signed-off-by: Ivan Bornyakov Fixes: 0d035bed2a4a ("net: sfp: VSOL V2801F / CarlitoxxPro CPGOS03-0490 v2.0 workaround") Cc: stable@vger.kernel.org Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- drivers/net/phy/sfp.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) (limited to 'drivers/net/phy/sfp.c') diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c index 8af10bb53e57..81edc457c5a1 100644 --- a/drivers/net/phy/sfp.c +++ b/drivers/net/phy/sfp.c @@ -210,6 +210,12 @@ static const enum gpiod_flags gpio_flags[] = { #define SFP_PHY_ADDR 22 #define SFP_PHY_ADDR_ROLLBALL 17 +/* SFP_EEPROM_BLOCK_SIZE is the size of data chunk to read the EEPROM + * at a time. Some SFP modules and also some Linux I2C drivers do not like + * reads longer than 16 bytes. + */ +#define SFP_EEPROM_BLOCK_SIZE 16 + struct sff_data { unsigned int gpios; bool (*module_supported)(const struct sfp_eeprom_id *id); @@ -1929,11 +1935,7 @@ static int sfp_sm_mod_probe(struct sfp *sfp, bool report) u8 check; int ret; - /* 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 = 16; + sfp->i2c_block_size = SFP_EEPROM_BLOCK_SIZE; ret = sfp_read(sfp, false, 0, &id.base, sizeof(id.base)); if (ret < 0) { @@ -2621,6 +2623,7 @@ static struct sfp *sfp_alloc(struct device *dev) return ERR_PTR(-ENOMEM); sfp->dev = dev; + sfp->i2c_block_size = SFP_EEPROM_BLOCK_SIZE; mutex_init(&sfp->sm_mutex); mutex_init(&sfp->st_mutex); -- cgit v1.2.3 From bef227c1537cb8005311c0842bc5449e8c7a5973 Mon Sep 17 00:00:00 2001 From: Ivan Bornyakov Date: Thu, 6 Apr 2023 16:08:33 +0300 Subject: net: sfp: avoid EEPROM read of absent SFP module If SFP module is not present, it is sensible to fail sfp_module_eeprom() and sfp_module_eeprom_by_page() early to avoid excessive I2C transfers which are garanteed to fail. Suggested-by: Andrew Lunn Signed-off-by: Ivan Bornyakov Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- drivers/net/phy/sfp.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/net/phy/sfp.c') diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c index 81edc457c5a1..bf345032d450 100644 --- a/drivers/net/phy/sfp.c +++ b/drivers/net/phy/sfp.c @@ -2487,6 +2487,9 @@ static int sfp_module_eeprom(struct sfp *sfp, struct ethtool_eeprom *ee, unsigned int first, last, len; int ret; + if (!(sfp->state & SFP_F_PRESENT)) + return -ENODEV; + if (ee->len == 0) return -EINVAL; @@ -2519,6 +2522,9 @@ static int sfp_module_eeprom_by_page(struct sfp *sfp, const struct ethtool_module_eeprom *page, struct netlink_ext_ack *extack) { + if (!(sfp->state & SFP_F_PRESENT)) + return -ENODEV; + if (page->bank) { NL_SET_ERR_MSG(extack, "Banks not supported"); return -EOPNOTSUPP; -- cgit v1.2.3