Input: atmel_mxt_ts - disable interrupt for 50ms after reset

The CHG/interrupt line is momentarily set (approximately 100 ms) as an
input after power-up or reset for diagnostic purposes. This may cause
spurious interrupts, so disable interrupt handler during this period.
Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/atmel_mxt_ts.c

@@ -1098,7 +1098,9 @@ static int mxt_soft_reset(struct mxt_data *data)
 	struct device *dev = &data->client->dev;
 	int ret = 0;
 
-	dev_info(dev, "Resetting chip\n");
+	dev_info(dev, "Resetting device\n");
+
+	disable_irq(data->irq);
 
 	reinit_completion(&data->reset_completion);
 
@@ -1106,6 +1108,11 @@ static int mxt_soft_reset(struct mxt_data *data)
 	if (ret)
 		return ret;
 
+	/* Ignore CHG line for 100ms after reset */
+	msleep(100);
+
+	enable_irq(data->irq);
+
 	ret = mxt_wait_for_completion(data, &data->reset_completion,
 				      MXT_RESET_TIMEOUT);
 	if (ret)