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From:   Dario Binacchi <dario.binacchi@amarulasolutions.com>
To:     linux-kernel@vger.kernel.org
Cc:     michael@amarulasolutions.com, linux-amarula@amarulasolutions.com,
        Dario Binacchi <dario.binacchi@amarulasolutions.com>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>,
        Oliver Graute <oliver.graute@kococonnector.com>,
        =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= 
        <u.kleine-koenig@pengutronix.de>,
        Wolfram Sang <wsa+renesas@sang-engineering.com>,
        linux-input@vger.kernel.org
Subject: [PATCH 8/9] Input: edt-ft5x06 - unify the crc check
Date:   Sun,  2 Apr 2023 22:09:50 +0200
Message-Id: <20230402200951.1032513-9-dario.binacchi@amarulasolutions.com>
In-Reply-To: <20230402200951.1032513-1-dario.binacchi@amarulasolutions.com>
References: <20230402200951.1032513-1-dario.binacchi@amarulasolutions.com>
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With this patch, the CRC is always verified by the same function, even in
the case of accessing registers where the number of bytes is minimal.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
---

 drivers/input/touchscreen/edt-ft5x06.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
index 8aae4c1e6b73..fdb32e3591be 100644
--- a/drivers/input/touchscreen/edt-ft5x06.c
+++ b/drivers/input/touchscreen/edt-ft5x06.c
@@ -240,13 +240,10 @@ static int edt_M06_i2c_read(void *context, const void *reg_buf, size_t reg_size,
 		if (!edt_ft5x06_ts_check_crc(tsdata, val_buf, val_size))
 			return -EIO;
 	} else if (reg_read) {
-		u8 crc = wbuf[0] ^ wbuf[1] ^ rbuf[0];
-
-		if (crc != rbuf[1]) {
-			dev_err(dev, "crc error: 0x%02x expected, got 0x%02x\n",
-				crc, rbuf[1]);
+		wbuf[2] = rbuf[0];
+		wbuf[3] = rbuf[1];
+		if (!edt_ft5x06_ts_check_crc(tsdata, wbuf, 4))
 			return -EIO;
-		}
 
 		*((u8 *)val_buf) = rbuf[0];
 	}
-- 
2.32.0