From patchwork Tue May 13 02:21:14 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 889706 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 08D3F1ADC7B; Tue, 13 May 2025 02:22:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747102925; cv=none; b=DTL+iVhH+609OLqpiaqgNn54T7gaOvpWTUOPsjqJ5NeIFt2gJBFE/rjkNFXsWNd6OqwJfywIL8h6IdFO4TT8y2dzbeIGk6Zj2B2CkYAnF8XmhS6M8YCqHNrg1kOgS/ixGama5hy7fvLJ40qj4w9620exHOyCBSXXYLZsXqOb4YY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747102925; c=relaxed/simple; bh=FGVKGRCRWFRrt7YM9cMW+5TsjRx+U8B96ORS1mkNgWM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZcuVRBJX+zZ2FidWc7Wf7YXxj4hvfqpYnvQakUe4mpWCmRv1gQNQeDUc49QfttoUNyuMx3fQyhkC43QvyGzypn9JRyDBcvJA598OpgUhE05a9FozczoO+4HrD866ncX4/5zhrofMoexyt7V1VelKC+XwLSdgzdRVQizyIlAPmMY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=slndntNz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="slndntNz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 51705C4CEF1; Tue, 13 May 2025 02:22:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747102924; bh=FGVKGRCRWFRrt7YM9cMW+5TsjRx+U8B96ORS1mkNgWM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=slndntNzj+GBxIRe0tkwuf2RsDdwTnePoYn1nNihJaiq0EudzsqQ6KjxXu4lM4e+2 DqRtNtj7b3AEaFf6lyFAoF5MRmc44ry2u4fgiba86e8AJs+mMJHOd2lqZpGVNM9b5Z IOXK6dBchbJJBFAjRugA4SEl0ENNOEJjq9D924elksSKc6vTg7RNsqr8JlGHx24zW7 BBNxjfxUkFSY/etYTrZMbH6y9APigML+XUV2s75tL8A1Z7e6dXWwzzBu+CZX4xAzp/ GTNGZUz8emtCkeues3oU3vjFhePUtTg63mo0xJyAm82oqdg5s8IdjQvtYb9MCHru2Y O5GnOir7wEpDg== From: Eric Biggers To: linux-kernel@vger.kernel.org Cc: linux-crypto@vger.kernel.org, Ard Biesheuvel , Krzysztof Kozlowski Subject: [PATCH 1/2] w1: ds2406: use crc16() instead of crc16_byte() loop Date: Mon, 12 May 2025 19:21:14 -0700 Message-ID: <20250513022115.39109-2-ebiggers@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250513022115.39109-1-ebiggers@kernel.org> References: <20250513022115.39109-1-ebiggers@kernel.org> Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Eric Biggers 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 --- 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);