From: Eric Biggers <ebiggers@google.com>
Date: Tue, 13 May 2025 02:21:14 +0000 (-0700)
Subject: w1: ds2406: use crc16() instead of crc16_byte() loop
X-Git-Tag: v6.16-rc1~207^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0769ebe279c0f07f5f01ef2dca9f425803039755;p=thirdparty%2Fkernel%2Flinux.git

w1: ds2406: use crc16() instead of crc16_byte() loop

Instead of looping through each byte and calling crc16_byte(), instead
just call crc16() on the whole buffer.  No functional change.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250513022115.39109-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
---

diff --git a/drivers/w1/slaves/w1_ds2406.c b/drivers/w1/slaves/w1_ds2406.c
index 1cae9b243ff87..76026d6151111 100644
--- a/drivers/w1/slaves/w1_ds2406.c
+++ b/drivers/w1/slaves/w1_ds2406.c
@@ -29,8 +29,6 @@ static ssize_t w1_f12_read_state(
 {
 	u8 w1_buf[6] = {W1_F12_FUNC_READ_STATUS, 7, 0, 0, 0, 0};
 	struct w1_slave *sl = kobj_to_w1_slave(kobj);
-	u16 crc = 0;
-	int i;
 	ssize_t rtnval = 1;
 
 	if (off != 0)
@@ -47,9 +45,7 @@ static ssize_t w1_f12_read_state(
 
 	w1_write_block(sl->master, w1_buf, 3);
 	w1_read_block(sl->master, w1_buf+3, 3);
-	for (i = 0; i < 6; i++)
-		crc = crc16_byte(crc, w1_buf[i]);
-	if (crc == 0xb001) /* good read? */
+	if (crc16(0, w1_buf, sizeof(w1_buf)) == 0xb001) /* good read? */
 		*buf = ((w1_buf[3]>>5)&3)|0x30;
 	else
 		rtnval = -EIO;
@@ -66,8 +62,6 @@ static ssize_t w1_f12_write_output(
 {
 	struct w1_slave *sl = kobj_to_w1_slave(kobj);
 	u8 w1_buf[6] = {W1_F12_FUNC_WRITE_STATUS, 7, 0, 0, 0, 0};
-	u16 crc = 0;
-	int i;
 	ssize_t rtnval = 1;
 
 	if (count != 1 || off != 0)
@@ -83,9 +77,7 @@ static ssize_t w1_f12_write_output(
 	w1_buf[3] = (((*buf)&3)<<5)|0x1F;
 	w1_write_block(sl->master, w1_buf, 4);
 	w1_read_block(sl->master, w1_buf+4, 2);
-	for (i = 0; i < 6; i++)
-		crc = crc16_byte(crc, w1_buf[i]);
-	if (crc == 0xb001) /* good read? */
+	if (crc16(0, w1_buf, sizeof(w1_buf)) == 0xb001) /* good read? */
 		w1_write_8(sl->master, 0xFF);
 	else
 		rtnval = -EIO;