Re: [PATCH v4 02/13] media: media/test_drivers: Replace open-coded parity calculation with parity_odd()

Hans Verkuil
2025-05-15T09:20:40Z

On 09/04/2025 17:43, Kuan-Wei Chiu wrote:
> Refactor parity calculations to use the standard parity_odd() helper.
> This change eliminates redundant implementations.
>
> Co-developed-by: Yu-Chun Lin <eleanor15x@gmail.com>
> Signed-off-by: Yu-Chun Lin <eleanor15x@gmail.com>
> Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>

Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl>

Regards,

Hans

> ---
> drivers/media/test-drivers/vivid/vivid-vbi-gen.c | 8 ++------
> 1 file changed, 2 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/media/test-drivers/vivid/vivid-vbi-gen.c b/drivers/media/test-drivers/vivid/vivid-vbi-gen.c
> index 70a4024d461e..5e1b7b1742e4 100644
> --- a/drivers/media/test-drivers/vivid/vivid-vbi-gen.c
> +++ b/drivers/media/test-drivers/vivid/vivid-vbi-gen.c
> @@ -5,6 +5,7 @@
> * Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
> */
>
> +#include <linux/bitops.h>
> #include <linux/errno.h>
> #include <linux/kernel.h>
> #include <linux/ktime.h>
> @@ -165,12 +166,7 @@ static const u8 vivid_cc_sequence2[30] = {
>
> static u8 calc_parity(u8 val)
> {
> - unsigned i;
> - unsigned tot = 0;
> -
> - for (i = 0; i < 7; i++)
> - tot += (val & (1 << i)) ? 1 : 0;
> - return val | ((tot & 1) ? 0 : 0x80);
> + return val | (parity_odd(val) ? 0 : 0x80);
> }
>
> static void vivid_vbi_gen_set_time_of_day(u8 *packet)