linux-kernel - [PATCH v8 42/52] Input: Atmel: improve error handling in mxt

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Date:   Thu, 19 Mar 2020 08:00:06 -0700
From:   Jiada Wang <jiada_wang@...tor.com>
To:     <nick@...anahar.org>, <dmitry.torokhov@...il.com>,
        <jikos@...nel.org>, <benjamin.tissoires@...hat.com>,
        <bsz@...ihalf.com>, <rydberg@...math.org>
CC:     <linux-input@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <erosca@...adit-jv.com>, <Andrew_Gabbasov@...tor.com>,
        <jiada_wang@...tor.com>
Subject: [PATCH v8 42/52] Input: Atmel: improve error handling in mxt_start()

From: Deepak Das <deepak_das@...tor.com>

mxt_start() does not return error in any of
the failure cases which will allow input_dev->open()
to return success even in case of any failure.

This commit modifies mxt_start() to return error
in failure cases.

Signed-off-by: Deepak Das <deepak_das@...tor.com>
Signed-off-by: George G. Davis <george_davis@...tor.com>
Signed-off-by: Jiada Wang <jiada_wang@...tor.com>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 31 ++++++++++++------------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 6ee83eda7170..2048cfbdc80c 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -3973,12 +3973,13 @@ static int mxt_start(struct mxt_data *data)
 
 	switch (data->suspend_mode) {
 	case MXT_SUSPEND_T9_CTRL:
-		mxt_soft_reset(data);
-
+		ret = mxt_soft_reset(data);
+		if (ret)
+			break;
 		/* Touch enable */
 		/* 0x83 = SCANEN | RPTEN | ENABLE */
-		mxt_write_object(data,
-				MXT_TOUCH_MULTI_T9, MXT_T9_CTRL, 0x83);
+		ret = mxt_write_object(data,
+				       MXT_TOUCH_MULTI_T9, MXT_T9_CTRL, 0x83);
 		break;
 
 	case MXT_SUSPEND_REGULATOR:
@@ -3992,27 +3993,26 @@ static int mxt_start(struct mxt_data *data)
 		 * Discard any touch messages still in message buffer
 		 * from before chip went to sleep
 		 */
-		mxt_process_messages_until_invalid(data);
+		ret = mxt_process_messages_until_invalid(data);
+		if (ret)
+			break;
 
 		ret = mxt_set_t7_power_cfg(data, MXT_POWER_CFG_RUN);
 		if (ret)
-			return ret;
+			break;
 
 		/* Recalibrate since chip has been in deep sleep */
 		ret = mxt_t6_command(data, MXT_COMMAND_CALIBRATE, 1, false);
 		if (ret)
-			return ret;
+			break;
 
 		ret = mxt_acquire_irq(data);
-		if (ret)
-			return ret;
-
-		break;
 	}
 
-	data->suspended = false;
+	if (!ret)
+		data->suspended = false;
 
-	return 0;
+	return ret;
 }
 
 static int mxt_stop(struct mxt_data *data)
@@ -4335,6 +4335,7 @@ static int __maybe_unused mxt_resume(struct device *dev)
 	struct i2c_client *client = to_i2c_client(dev);
 	struct mxt_data *data = i2c_get_clientdata(client);
 	struct input_dev *input_dev = data->input_dev;
+	int ret = 0;
 
 	if (!input_dev)
 		return 0;
@@ -4344,11 +4345,11 @@ static int __maybe_unused mxt_resume(struct device *dev)
 	mutex_lock(&input_dev->mutex);
 
 	if (input_dev->users)
-		mxt_start(data);
+		ret = mxt_start(data);
 
 	mutex_unlock(&input_dev->mutex);
 
-	return 0;
+	return ret;
 }
 
 static SIMPLE_DEV_PM_OPS(mxt_pm_ops, mxt_suspend, mxt_resume);
-- 
2.17.1