Commit b4881070 authored by Heiko Stuebner's avatar Heiko Stuebner Committed by Lee Jones
Browse files

mfd: qnap-mcu: Calculate the checksum on the actual number of bytes received 



In the case of an error message, the number of received bytes can be
less than originally expected but still contain a valid message.

If the transfer itself ended in an error we would exit earlier already.

So calculate the checksum on the number of received bytes and not the
number of expected bytes.

Signed-off-by: default avatarHeiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20251113165218.449616-2-heiko@sntech.de


Signed-off-by: default avatarLee Jones <lee@kernel.org>
parent 46bddb5f

drivers/mfd/qnap-mcu.c

+2 −2
Original line number Diff line number Diff line
@@ -175,8 +175,8 @@ int qnap_mcu_exec(struct qnap_mcu *mcu, 
		return -ETIMEDOUT;

	}



	crc = qnap_mcu_csum(rx, reply_data_size);

	if (crc != rx[reply_data_size]) {

	crc = qnap_mcu_csum(rx, reply->received - QNAP_MCU_CHECKSUM_SIZE);

	if (crc != rx[reply->received - QNAP_MCU_CHECKSUM_SIZE]) {

		dev_err(&mcu->serdev->dev, "Invalid Checksum received\n");

		return -EIO;

	}