RE: [PATCH 4/4] wifi: rtw88: rtw8822c: simplify amplitude search and offset via s32

Arsenii Pashchenko <[email protected]> wrote:
> Complete the signed data transition by removing the complex
> rtw8822c_rf_minmax_cmp() helper. On a true linear s32 scale, finding
> the delta amplitude simplifies to a direct difference (max - min)
> without any nested circular wrap-around conditions.
> 
> Refactor rtw8822c_dac_iq_offset() to directly calculate the trimmed
> arithmetic mean, casting back to the hardware register's offset
> orientation only at the final assignment using a ternary operator.
> 
> Signed-off-by: Arsenii Pashchenko <[email protected]>
> ---
>  drivers/net/wireless/realtek/rtw88/rtw8822c.c | 103 +++++-------------
>  1 file changed, 25 insertions(+), 78 deletions(-)
> 
> diff --git a/drivers/net/wireless/realtek/rtw88/rtw8822c.c
> b/drivers/net/wireless/realtek/rtw88/rtw8822c.c
> index 642ac2e2b..6fcdfc64c 100644
> --- a/drivers/net/wireless/realtek/rtw88/rtw8822c.c
> +++ b/drivers/net/wireless/realtek/rtw88/rtw8822c.c
> @@ -155,38 +155,6 @@ static void rtw8822c_dac_restore_reg(struct rtw_dev *rtwdev,
>         }
>  }
> 
> -static void rtw8822c_rf_minmax_cmp(struct rtw_dev *rtwdev, s32 value_s32,
> -                                  s32 *min_s32, s32 *max_s32)
> -{
> -       u32 value = (u32)value_s32;
> -       u32 *min = (u32 *)min_s32;
> -       u32 *max = (u32 *)max_s32;
> -       if (value >= 0x200) {
> -               if (*min >= 0x200) {
> -                       if (*min > value)
> -                               *min = value;
> -               } else {
> -                       *min = value;
> -               }
> -               if (*max >= 0x200) {
> -                       if (*max < value)
> -                               *max = value;
> -               }
> -       } else {
> -               if (*min < 0x200) {
> -                       if (*min > value)
> -                               *min = value;
> -               }
> -
> -               if (*max  >= 0x200) {
> -                       *max = value;
> -               } else {
> -                       if (*max < value)
> -                               *max = value;
> -               }
> -       }
> -}
> -
>  static int rtw8822c_dac_iq_cmp_s32(const void *a, const void *b)
>  {
>         s32 va = *(const s32 *)a;
> @@ -201,31 +169,16 @@ static void rtw8822c_dac_iq_sort(struct rtw_dev *rtwdev, s32 *iv, s32 *qv)
>         sort(qv, DACK_SN_8822C, sizeof(s32), rtw8822c_dac_iq_cmp_s32, NULL);
>  }
> 
> -static void rtw8822c_dac_iq_offset(struct rtw_dev *rtwdev, s32 *vec_s32, u32 *val)
> +static s32 rtw8822c_dac_iq_offset(struct rtw_dev *rtwdev, s32 *vec)
>  {
> -       u32 *vec = (u32 *)vec_s32;
> -       u32 p, m, t, i;
> +       s32 sum = 0;
> 
> -       m = 0;
> -       p = 0;
> -       for (i = 10; i < DACK_SN_8822C - 10; i++) {
> -               if (vec[i] > 0x200)
> -                       m = (0x400 - vec[i]) + m;
> -               else
> -                       p = vec[i] + p;
> -       }
> +       for (u32 i = 10; i < DACK_SN_8822C - 10; i++)
> +               sum += vec[i];
> 
> -       if (p > m) {
> -               t = p - m;
> -               t = t / (DACK_SN_8822C - 20);
> -       } else {
> -               t = m - p;
> -               t = t / (DACK_SN_8822C - 20);
> -               if (t != 0x0)
> -                       t = 0x400 - t;
> -       }
> +       s32 avg = sum / (DACK_SN_8822C - 20);

No declaration in the middle. 

> 
> -       *val = t;
> +       return avg >= 0 ? avg : 0x400 + avg;

Return type is 's32', but here doesn't do sign_extension()?

>  }
> 
>  static u32 rtw8822c_get_path_write_addr(u8 path)