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authorWolfram Sang2015-03-23 09:26:39 +0100
committerWolfram Sang2015-03-27 16:53:40 +0100
commit98e982b3a29829b676b723e42c1184c87e5242d0 (patch)
treeb65bd89a53eed65aecf4d95229cba99825e5ab5c /drivers/i2c
parentd0c892f59c918535f902caea63637af87d931d91 (diff)
i2c: slave-eeprom: add more info when to increase the pointer
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@sang-engineering.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/i2c-slave-eeprom.c6
1 files changed, 6 insertions, 0 deletions
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: