From: Eric Biggers <ebiggers@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: linux-crypto@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org>,
Krzysztof Kozlowski <krzk@kernel.org>
Subject: [PATCH 1/2] w1: ds2406: use crc16() instead of crc16_byte() loop
Date: Mon, 12 May 2025 19:21:14 -0700 [thread overview]
Message-ID: <20250513022115.39109-2-ebiggers@kernel.org> (raw)
In-Reply-To: <20250513022115.39109-1-ebiggers@kernel.org>
From: Eric Biggers <ebiggers@google.com>
Instead of looping through each byte and calling crc16_byte(), instead
just call crc16() on the whole buffer. No functional change.
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
drivers/w1/slaves/w1_ds2406.c | 12 ++----------
1 file changed, 2 insertions(+), 10 deletions(-)
diff --git a/drivers/w1/slaves/w1_ds2406.c b/drivers/w1/slaves/w1_ds2406.c
index 1cae9b243ff8..76026d615111 100644
--- a/drivers/w1/slaves/w1_ds2406.c
+++ b/drivers/w1/slaves/w1_ds2406.c
@@ -27,12 +27,10 @@ static ssize_t w1_f12_read_state(
const struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t count)
{
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)
return 0;
if (!buf)
@@ -45,13 +43,11 @@ static ssize_t w1_f12_read_state(
return -EIO;
}
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;
mutex_unlock(&sl->master->bus_mutex);
@@ -64,12 +60,10 @@ static ssize_t w1_f12_write_output(
const struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t count)
{
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)
return -EFAULT;
@@ -81,13 +75,11 @@ 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;
mutex_unlock(&sl->master->bus_mutex);
--
2.49.0
next prev parent reply other threads:[~2025-05-13 2:22 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-13 2:21 [PATCH 0/2] lib/crc16: unexport crc16_table and crc16_byte() Eric Biggers
2025-05-13 2:21 ` Eric Biggers [this message]
2025-05-13 7:52 ` [PATCH 1/2] w1: ds2406: use crc16() instead of crc16_byte() loop Krzysztof Kozlowski
2025-05-13 2:21 ` [PATCH 2/2] lib/crc16: unexport crc16_table and crc16_byte() Eric Biggers
2025-05-13 9:42 ` [PATCH 0/2] " Ard Biesheuvel
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