goodix_ts_data structure contains abs_x_max and abs_y_max members,
which contain already swapped maximum ranges. That causes reporting
touch events with invalid position (out of range values).
Problem occurs for example when ts->inverted_x and ts->swapped_x_y are
true, but ts->inverted_y is false. Assuming we have 720x1280 touch
panel, ts->abs_x_max == 1279 and ts->abs_y_max == 719 (because we
inverted that in goodix_read_config()). Now let's assume that we
received event from (0:0) position (in touch panel original
coordinates). In function goodix_ts_report_touch() we calculate
input_x as 1279, but after swapping input_y takes that value (which is
more that maximum 719 value reported during initialization).
Take into account that abs_x_max and abs_y_max are already swapped
in goodix_ts_report_touch(), so position for inverted axes will be
calculated correctly.
Signed-off-by: Marcin Niestroj <m.niestroj@xxxxxxxxxxxxxxxx>
Fixes: ad48cf5e9597 ("Input: goodix - add axis swapping and axis inversion support")
---
Changes v2 -> v3 (suggested by Bastien):
- add explanation about when the problem occurs
Changes v1 -> v2 (suggested by Bastien):
- patch splitted off from patch 3
drivers/input/touchscreen/goodix.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index 7896097ca69b..dc832890f6d3 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -296,12 +296,18 @@ static void goodix_ts_report_touch(struct goodix_ts_data *ts, u8 *coor_data)
int input_w = get_unaligned_le16(&coor_data[5]);
/* Inversions have to happen before axis swapping */
- if (ts->inverted_x)
- input_x = ts->abs_x_max - input_x;
- if (ts->inverted_y)
- input_y = ts->abs_y_max - input_y;
- if (ts->swapped_x_y)
+ if (!ts->swapped_x_y) {
+ if (ts->inverted_x)
+ input_x = ts->abs_x_max - input_x;
+ if (ts->inverted_y)
+ input_y = ts->abs_y_max - input_y;
+ } else {
+ if (ts->inverted_x)
+ input_x = ts->abs_y_max - input_x;
+ if (ts->inverted_y)
+ input_y = ts->abs_x_max - input_y;
swap(input_x, input_y);
+ }
input_mt_slot(ts->input_dev, id);
input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER, true);
--
2.16.1
--
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