From 98e982b3a29829b676b723e42c1184c87e5242d0 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Mon, 23 Mar 2015 09:26:39 +0100 Subject: i2c: slave-eeprom: add more info when to increase the pointer MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Acked-by: Uwe Kleine-König Signed-off-by: Wolfram Sang --- drivers/i2c/i2c-slave-eeprom.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-slave-eeprom.c b/drivers/i2c/i2c-slave-eeprom.c index 3fb45d894d80..822374654609 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: -- cgit v1.2.3