From: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> It is a bit subtle when to correctly increase the buffer index when reading. Make this clearer by adding some more comments and pointers to the docs. Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> --- Changes since V1: new patch drivers/i2c/i2c-slave-eeprom.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/i2c/i2c-slave-eeprom.c b/drivers/i2c/i2c-slave-eeprom.c index 3fb45d894d8072..8223746546093c 100644 --- a/drivers/i2c/i2c-slave-eeprom.c +++ b/drivers/i2c/i2c-slave-eeprom.c @@ -48,12 +48,18 @@ static int i2c_slave_eeprom_slave_cb(struct i2c_client *client, break; case I2C_SLAVE_READ_PROCESSED: + /* The previous byte made it to the bus, get next one */ eeprom->buffer_idx++; /* fallthrough */ case I2C_SLAVE_READ_REQUESTED: spin_lock(&eeprom->buffer_lock); *val = eeprom->buffer[eeprom->buffer_idx]; spin_unlock(&eeprom->buffer_lock); + /* + * Do not increment buffer_idx here, because we don't know if + * this byte will be actually used. Read Linux I2C slave docs + * for details. + */ break; case I2C_SLAVE_STOP: -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
