On Mon, Nov 27, 2017 at 11:06 PM, Bartosz Golaszewski <[email protected]> wrote: > There's an ilog2() expansion in AT24_DEVICE_MAGIC() which rounds down > the actual size of EUI-48 byte array in at24mac402 eeproms to 4 from 6, > making it impossible to read it all. > > Fix it by manually adjusting the value in probe(). > > This patch contains a temporary fix that is suitable for stable > branches. Eventually we'll probably remove the call to ilog2() while > converting the magic values to actual structs. >
Reviewed-by: Andy Shevchenko <[email protected]> > Cc: [email protected] > Fixes: 0b813658c115 ("eeprom: at24: add support for at24mac series") > Signed-off-by: Bartosz Golaszewski <[email protected]> > --- > drivers/misc/eeprom/at24.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c > index e0b4b36ef010..783244b485cc 100644 > --- a/drivers/misc/eeprom/at24.c > +++ b/drivers/misc/eeprom/at24.c > @@ -730,6 +730,16 @@ static int at24_probe(struct i2c_client *client, const > struct i2c_device_id *id) > dev_warn(&client->dev, > "page_size looks suspicious (no power of 2)!\n"); > > + /* > + * REVISIT: the size of the EUI-48 byte array is 6 in at24mac402, > while > + * the call to ilog2() in AT24_DEVICE_MAGIC() rounds it down to 4. > + * > + * Eventually we'll get rid of the magic values altoghether in favor > of > + * real structs, but for now just manually set the right size. > + */ > + if (chip.flags & AT24_FLAG_MAC && chip.byte_len == 4) > + chip.byte_len = 6; > + > /* Use I2C operations unless we're stuck with SMBus extensions. */ > if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { > if (chip.flags & AT24_FLAG_ADDR16) > -- > 2.15.0 > -- With Best Regards, Andy Shevchenko
