Commit c3223f56 authored by Heiko Stuebner's avatar Heiko Stuebner Committed by Lee Jones
Browse files

mfd: qnap-mcu: Move checksum verification to its own function 



We'll need the checksum check in a second place in the future, so
move the verification code to a separate function.

Signed-off-by: default avatarHeiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20251113165218.449616-4-heiko@sntech.de


Signed-off-by: default avatarLee Jones <lee@kernel.org>
parent c94fce30

drivers/mfd/qnap-mcu.c

+8 −3
Original line number Diff line number Diff line
@@ -78,6 +78,13 @@ static u8 qnap_mcu_csum(const u8 *buf, size_t size) 
	return csum;

}



static bool qnap_mcu_verify_checksum(const u8 *buf, size_t size)

{

	u8 crc = qnap_mcu_csum(buf, size - QNAP_MCU_CHECKSUM_SIZE);



	return crc == buf[size - QNAP_MCU_CHECKSUM_SIZE];

}



static int qnap_mcu_write(struct qnap_mcu *mcu, const u8 *data, u8 data_size)

{

	unsigned char tx[QNAP_MCU_TX_BUFFER_SIZE];
@@ -150,7 +157,6 @@ int qnap_mcu_exec(struct qnap_mcu *mcu, 
	size_t length = reply_data_size + QNAP_MCU_CHECKSUM_SIZE;

	struct qnap_mcu_reply *reply = &mcu->reply;

	int ret = 0;

	u8 crc;



	if (length > sizeof(rx)) {

		dev_err(&mcu->serdev->dev, "expected data too big for receive buffer");
@@ -175,8 +181,7 @@ int qnap_mcu_exec(struct qnap_mcu *mcu, 
		return -ETIMEDOUT;

	}



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

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

	if (!qnap_mcu_verify_checksum(rx, reply->received)) {

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

		return -EPROTO;

	}