[PATCH] Input: elan_i2c - Clean INT stats in FW updating for old Elan touchpad

[KT Liao]

Some old touchapd FWs have interrupt issue after FW updating.
Use reading 34 bytes before IC reset command to clean INT stauts
The modification has been tested in some chromebook system
It should not affect general touchpad in Linux system.

Signed-off-by: KT Liao <kt.liao@xxxxxxxxxx>
---
 drivers/input/mouse/elan_i2c_i2c.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/input/mouse/elan_i2c_i2c.c b/drivers/input/mouse/elan_i2c_i2c.c
index 3be75c6e..842f852 100644
--- a/drivers/input/mouse/elan_i2c_i2c.c
+++ b/drivers/input/mouse/elan_i2c_i2c.c
@@ -612,7 +612,14 @@ static int elan_i2c_finish_fw_update(struct i2c_client *client,
 	long ret;
 	int error;
 	int len;
-	u8 buffer[ETP_I2C_INF_LENGTH];
+	u8 buffer[ETP_I2C_REPORT_LEN];
+
+	len = i2c_master_recv(client, buffer, ETP_I2C_REPORT_LEN);
+	if (len != ETP_I2C_REPORT_LEN) {
+		error = len < 0 ? len : -EIO;
+		dev_warn(dev, "failed to read I2C data after FW WDT reset: %d (%d)\n",
+			error, len);
+	}
 
 	reinit_completion(completion);
 	enable_irq(client->irq);
-- 
2.7.4