input: goodix: Don't retry individual reads when polling

Some Goodix controllers report the buffer isn't ready
continuously when there are no touch points to report. That
triggers the retry mechanism within the driver required as
supposedly the data can be 10ms after the interrupt occurs.

Seeing as we don't have an interrupt there is little point
in retrying, and we can wait for the next poll event.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

Author: 6by9

drivers/input/touchscreen/goodix.c

@@ -299,6 +299,14 @@ static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
 				return 0;
 		}
 
+		if (!ts->client->irq)
+			/*
+			 * No point in retrying if polling, particularly as some
+			 * versions continuously report "not ready" if there are
+			 * no touch points.
+			 */
+			break;
+
 		usleep_range(1000, 2000); /* Poll every 1 - 2 ms */
 	} while (time_before(jiffies, max_timeout));