| Message ID | 20230406130833.32160-2-i.bornyakov@metrotek.ru (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 813c2dd78618f108fdcf9cd726ea90f081ee2881 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | fix EEPROM read of absent SFP module | expand |
| Context | Check | Description |
|---|---|---|
| netdev/series_format | success | Posting correctly formatted |
| netdev/tree_selection | success | Clearly marked for net |
| netdev/fixes_present | success | Fixes tag present in non-next series |
| netdev/header_inline | success | No static functions without inline keyword in header files |
| netdev/build_32bit | success | Errors and warnings before: 18 this patch: 18 |
| netdev/cc_maintainers | success | CCed 8 of 8 maintainers |
| netdev/build_clang | success | Errors and warnings before: 18 this patch: 18 |
| netdev/verify_signedoff | success | Signed-off-by tag matches author and committer |
| netdev/deprecated_api | success | None detected |
| netdev/check_selftest | success | No net selftest shell script |
| netdev/verify_fixes | success | Fixes tag looks correct |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 18 this patch: 18 |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 31 lines checked |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/source_inline | success | Was 0 now: 0 |
On Thu, Apr 06, 2023 at 04:08:32PM +0300, Ivan Bornyakov wrote: > 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 <i.bornyakov@metrotek.ru> > Fixes: 0d035bed2a4a ("net: sfp: VSOL V2801F / CarlitoxxPro CPGOS03-0490 v2.0 workaround") > Cc: stable@vger.kernel.org Reviewed-by: Andrew Lunn <andrew@lunn.ch> Andrew
diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c index 40c9a64c5e30..5663a184644d 100644 --- a/drivers/net/phy/sfp.c +++ b/drivers/net/phy/sfp.c @@ -212,6 +212,12 @@ 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); @@ -1928,11 +1934,7 @@ 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) { @@ -2615,6 +2617,7 @@ 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);
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 <i.bornyakov@metrotek.ru> Fixes: 0d035bed2a4a ("net: sfp: VSOL V2801F / CarlitoxxPro CPGOS03-0490 v2.0 workaround") Cc: stable@vger.kernel.org --- drivers/net/phy/sfp.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)