| Message ID | 4f62e18a-fc2d-f24f-f549-46b97f882cfc@gmail.com |
|---|---|
| State | Superseded |
| Delegated to: | Bartosz Golaszewski |
| Headers | show |
| Series | eeprom: at24: fix reading from 24MAC402/24MAC602 | expand |
2017-11-24 7:42 GMT+01:00 Heiner Kallweit <hkallweit1@gmail.com>: > Chip datasheet mentions that word addresses other than the actual > start position of the MAC delivers undefined results. So fix this. > Could you also mention in the commit message, that the current implementation doesn't work because the offset is simply wrong? Thanks, Bartosz > Fixes: 0b813658c115 "eeprom: at24: add support for at24mac series" > Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> > --- > drivers/misc/eeprom/at24.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c > index e0b4b36ef..00d602be7 100644 > --- a/drivers/misc/eeprom/at24.c > +++ b/drivers/misc/eeprom/at24.c > @@ -425,7 +425,8 @@ static ssize_t at24_eeprom_read_mac(struct at24_data *at24, char *buf, > memset(msg, 0, sizeof(msg)); > msg[0].addr = client->addr; > msg[0].buf = addrbuf; > - addrbuf[0] = 0x90 + offset; > + /* EUI-48 starts from 0x9a, EUI-64 from 0x98 */ > + addrbuf[0] = 0xa0 - at24->chip.byte_len + offset; > msg[0].len = 1; > msg[1].addr = client->addr; > msg[1].flags = I2C_M_RD; > -- > 2.15.0 >
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index e0b4b36ef..00d602be7 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -425,7 +425,8 @@ static ssize_t at24_eeprom_read_mac(struct at24_data *at24, char *buf, memset(msg, 0, sizeof(msg)); msg[0].addr = client->addr; msg[0].buf = addrbuf; - addrbuf[0] = 0x90 + offset; + /* EUI-48 starts from 0x9a, EUI-64 from 0x98 */ + addrbuf[0] = 0xa0 - at24->chip.byte_len + offset; msg[0].len = 1; msg[1].addr = client->addr; msg[1].flags = I2C_M_RD;
Chip datasheet mentions that word addresses other than the actual start position of the MAC delivers undefined results. So fix this. Fixes: 0b813658c115 "eeprom: at24: add support for at24mac series" Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> --- drivers/misc/eeprom/at24.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)