[PATCH v3 2/3] Input: ilitek_ts: handle short I2C transfers

[Kristian Mide]

Check that i2c_transfer() returns the expected number of
messages in ilitek_i2c_write_and_read().

Short transfers were previously treated as success, allowing
callers to continue with partially filled buffers. In the report
path that can expose uninitialized stack data through debugging
output and can also confuse packet parsing.

Signed-off-by: Kristian Mide <kristian@xxxxxxx>
---
 drivers/input/touchscreen/ilitek_ts_i2c.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/input/touchscreen/ilitek_ts_i2c.c b/drivers/input/touchscreen/ilitek_ts_i2c.c
index 86975fa9a..a184d024d 100644
--- a/drivers/input/touchscreen/ilitek_ts_i2c.c
+++ b/drivers/input/touchscreen/ilitek_ts_i2c.c
@@ -131,11 +131,15 @@ static int ilitek_i2c_write_and_read(struct ilitek_ts_data *ts,
 		error = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 		if (error < 0)
 			return error;
+		if (error != ARRAY_SIZE(msgs))
+			return -EIO;
 	} else {
 		if (write_len > 0) {
 			error = i2c_transfer(client->adapter, msgs, 1);
 			if (error < 0)
 				return error;
+			if (error != 1)
+				return -EIO;
 		}
 		if (delay > 0)
 			fsleep(delay * 1000);
@@ -144,6 +148,8 @@ static int ilitek_i2c_write_and_read(struct ilitek_ts_data *ts,
 			error = i2c_transfer(client->adapter, msgs + 1, 1);
 			if (error < 0)
 				return error;
+			if (error != 1)
+				return -EIO;
 		}
 	}
 
-- 
2.54.0