Zforce touch data packet consists of a byte representing number of contacts followed by several chunks with length of 9 bytes representing each contact. Instead of accounting for the leading byte by increasing offset of each field in contacts by one introduce a pointer to contact data and point it appropriately. This avoids awkward constructs like: point.prblty = payload[9 * i + 9]; which makes it seem like there is off-by-one error, in favor of more straightforward: point.prblty = p[8]; Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> --- drivers/input/touchscreen/zforce_ts.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/drivers/input/touchscreen/zforce_ts.c b/drivers/input/touchscreen/zforce_ts.c index 32f3d74bd339..c5b4c85359b4 100644 --- a/drivers/input/touchscreen/zforce_ts.c +++ b/drivers/input/touchscreen/zforce_ts.c @@ -318,6 +318,7 @@ static int zforce_touch_event(struct zforce_ts *ts, u8 *payload) struct i2c_client *client = ts->client; struct zforce_point point; int count, i, num = 0; + u8 *p; count = payload[0]; if (count > ZFORCE_REPORT_POINTS) { @@ -328,8 +329,10 @@ static int zforce_touch_event(struct zforce_ts *ts, u8 *payload) } for (i = 0; i < count; i++) { - point.coord_x = get_unaligned_le16(&payload[9 * i + 1]); - point.coord_y = get_unaligned_le16(&payload[9 * i + 3]); + p = &payload[i * 9 + 1]; + + point.coord_x = get_unaligned_le16(&p[0]); + point.coord_y = get_unaligned_le16(&p[2]); if (point.coord_x > ts->prop.max_x || point.coord_y > ts->prop.max_y) { @@ -338,18 +341,16 @@ static int zforce_touch_event(struct zforce_ts *ts, u8 *payload) point.coord_x = point.coord_y = 0; } - point.state = payload[9 * i + 5] & 0x0f; - point.id = (payload[9 * i + 5] & 0xf0) >> 4; + point.state = p[4] & 0x0f; + point.id = (p[4] & 0xf0) >> 4; /* determine touch major, minor and orientation */ - point.area_major = max(payload[9 * i + 6], - payload[9 * i + 7]); - point.area_minor = min(payload[9 * i + 6], - payload[9 * i + 7]); - point.orientation = payload[9 * i + 6] > payload[9 * i + 7]; - - point.pressure = payload[9 * i + 8]; - point.prblty = payload[9 * i + 9]; + point.area_major = max(p[5], p[6]); + point.area_minor = min(p[5], p[6]); + point.orientation = p[5] > p[6]; + + point.pressure = p[7]; + point.prblty = p[8]; dev_dbg(&client->dev, "point %d/%d: state %d, id %d, pressure %d, prblty %d, x %d, y %d, amajor %d, aminor %d, ori %d\n", -- 2.46.0.295.g3b9ea8a38a-goog