[PATCH] Input: atmel_mxt_ts - Fix lost interrupts

[Linus Walleij <linus.walleij@linaro.org>]

After commit 74d905d2d38a devices requiring the workaround
for edge triggered interrupts stopped working.

This is because the "data" state container defaults to
*not* using the workaround, but the workaround gets used
*before* the check of whether it is needed or not. This
semantic is not obvious from just looking on the patch,
but related to the program flow.

The hardware needs the quirk to be used before even
proceeding to check if the quirk is needed.

This patch makes the quirk be used until we determine
it is *not* needed.

Cc: Andre <andre.muller@web.de>
Cc: Nick Dyer <nick.dyer@itdev.co.uk>
Cc: Jiada Wang <jiada_wang@mentor.com>
Cc: stable@vger.kernel.org
Fixes: 74d905d2d38a ("Input: atmel_mxt_ts - only read messages in mxt_acquire_irq() when necessary")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index e34984388791..f25b2f6038a7 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -1297,8 +1297,6 @@ static int mxt_check_retrigen(struct mxt_data *data)
 	int val;
 	struct irq_data *irqd;
 
-	data->use_retrigen_workaround = false;
-
 	irqd = irq_get_irq_data(data->irq);
 	if (!irqd)
 		return -EINVAL;
@@ -1313,8 +1311,10 @@ static int mxt_check_retrigen(struct mxt_data *data)
 		if (error)
 			return error;
 
-		if (val & MXT_COMMS_RETRIGEN)
+		if (val & MXT_COMMS_RETRIGEN) {
+			data->use_retrigen_workaround = false;
 			return 0;
+		}
 	}
 
 	dev_warn(&client->dev, "Enabling RETRIGEN workaround\n");
@@ -3117,6 +3117,7 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
 	data = devm_kzalloc(&client->dev, sizeof(struct mxt_data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
+	data->use_retrigen_workaround = true;
 
 	snprintf(data->phys, sizeof(data->phys), "i2c-%u-%04x/input0",
 		 client->adapter->nr, client->addr);
-- 
2.26.2