Input: goodix - check the 'buffer status' bit before reading data

The MSB of the first byte read via I2C at the coordinates address
indicates whether the data is valid or ready (called "buffer status" in
the datasheets) when an interrupt is raised. Previously, this bit was
ignored, which resulted in a lot of incorrect detections of "finger
removed" events.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Acked-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index 3af16984d57c908afdf9b801370ab2c76389d7f6..0d93b1e5e28e13187d9160f9985f29857e5df8e4 100644 (file)
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -101,6 +101,9 @@ static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
                return error;
        }
 
+       if (!(data[0] & 0x80))
+               return -EAGAIN;
+
        touch_num = data[0] & 0x0f;
        if (touch_num > ts->max_touch_num)
                return -EPROTO;