From 656155d07658e84ac6ab6f6eceac67b807d6fedb Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Mon, 27 Nov 2017 22:06:13 +0100 Subject: eeprom: at24: correctly set the size for at24mac402 commit 5478e478eee3b096b8d998d4ed445da30da2dfbc upstream. 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. Fixes: 0b813658c115 ("eeprom: at24: add support for at24mac series") Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko Signed-off-by: Greg Kroah-Hartman --- drivers/misc/eeprom/at24.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers/misc') diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index bfd1a6f4ebf6..e0d018e8bb8e 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -632,6 +632,16 @@ 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) -- cgit v1.2.3