linux-kernel - [PATCH 3/4] Input: zforce - Remove unnecessary payload data checks

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Date:	Mon, 27 Jan 2014 19:46:12 +0100
From:	Luis Ortega <luiorpe1@....es>
To:	dmitry.torokhov@...il.com
Cc:	heiko@...ech.de, yongjun_wei@...ndmicro.com.cn,
	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
	Luis Ortega <luiorpe1@....es>
Subject: [PATCH 3/4] Input: zforce - Remove unnecessary payload data checks

The function zforce_read_packet() reads 2 values (bytes) of payload
header, validates them and then proceeds to read the payload body.
The function stores all these in a u8 buffer.

The PAYLOAD_LENGTH check seems to be trying to detect an overflow error.
However, since we are just reading a u8 value from the buffer, these
checks are unnecessary and we should simply compare against zero.

Signed-off-by: Luis Ortega <luiorpe1@....es>
---
 drivers/input/touchscreen/zforce_ts.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/zforce_ts.c b/drivers/input/touchscreen/zforce_ts.c
index c1b6b82..e082d5c 100644
--- a/drivers/input/touchscreen/zforce_ts.c
+++ b/drivers/input/touchscreen/zforce_ts.c
@@ -423,7 +423,7 @@ static int zforce_read_packet(struct zforce_ts *ts, u8 *buf)
 		goto unlock;
 	}
 
-	if (buf[PAYLOAD_LENGTH] <= 0 || buf[PAYLOAD_LENGTH] > 255) {
+	if (buf[PAYLOAD_LENGTH] == 0) {
 		dev_err(&client->dev, "invalid payload length: %d\n",
 			buf[PAYLOAD_LENGTH]);
 		ret = -EIO;
-- 
1.8.5.3

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