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| author | Ivan Bornyakov <i.bornyakov@metrotek.ru> | 2023-04-06 16:08:32 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-04-20 12:10:27 +0200 |
| commit | cf22c98bcbf8fc0660a1f09fe324fd4f45ae179a (patch) | |
| tree | 821357daa5d41043781bc16cb0b53e977a4dd318 | |
| parent | 2a4835b8ede001ce88a34f6f0295f4ece2212174 (diff) | |
| download | linux-stable-cf22c98bcbf8fc0660a1f09fe324fd4f45ae179a.tar.gz linux-stable-cf22c98bcbf8fc0660a1f09fe324fd4f45ae179a.tar.bz2 linux-stable-cf22c98bcbf8fc0660a1f09fe324fd4f45ae179a.zip | |
net: sfp: initialize sfp->i2c_block_size at sfp allocation
commit 813c2dd78618f108fdcf9cd726ea90f081ee2881 upstream.
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/net/phy/sfp.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c index dcbe278086dc..6a5f40f11db3 100644 --- a/drivers/net/phy/sfp.c +++ b/drivers/net/phy/sfp.c @@ -207,6 +207,12 @@ static const enum gpiod_flags gpio_flags[] = { */ #define SFP_PHY_ADDR 22 +/* 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); @@ -1754,11 +1760,7 @@ 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) { @@ -2385,6 +2387,7 @@ 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); |