On 31/08/23 06:26, haibo.chen@xxxxxxx wrote:
> From: Haibo Chen <haibo.chen@xxxxxxx>
>
> Current manual tuning logic only get the first pass window, but
> this pass window maybe not the best pass window.
>
> Now find all the pass window, and chose the largest pass window,
> and use the average value of this largest pass window to get the
> best timing.
>
> Signed-off-by: Haibo Chen <haibo.chen@xxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-esdhc-imx.c | 52 +++++++++++++++++++++---------
> 1 file changed, 36 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
> index 6170b7121f36..4cbbc0a786a0 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -1154,32 +1154,52 @@ static void esdhc_post_tuning(struct sdhci_host *host)
> writel(reg, host->ioaddr + ESDHC_MIX_CTRL);
> }
>
> +/*
> + * find the largest pass window, and use the average delay of this
> + * largest window to get the best timing.
> + */
> static int esdhc_executing_tuning(struct sdhci_host *host, u32 opcode)
> {
> int min, max, avg, ret;
> + int win_length, target_min, target_max, target_win_length;
>
> - /* find the mininum delay first which can pass tuning */
> min = ESDHC_TUNE_CTRL_MIN;
> - while (min < ESDHC_TUNE_CTRL_MAX) {
> - esdhc_prepare_tuning(host, min);
> - if (!mmc_send_tuning(host->mmc, opcode, NULL))
> - break;
> - min += ESDHC_TUNE_CTRL_STEP;
> - }
> -
> - /* find the maxinum delay which can not pass tuning */
> - max = min + ESDHC_TUNE_CTRL_STEP;
> + max = ESDHC_TUNE_CTRL_MIN;
> + target_win_length = 0;
> while (max < ESDHC_TUNE_CTRL_MAX) {
> - esdhc_prepare_tuning(host, max);
> - if (mmc_send_tuning(host->mmc, opcode, NULL)) {
> - max -= ESDHC_TUNE_CTRL_STEP;
> - break;
> + /* find the mininum delay first which can pass tuning */
> + while (min < ESDHC_TUNE_CTRL_MAX) {
> + esdhc_prepare_tuning(host, min);
> + if (!mmc_send_tuning(host->mmc, opcode, NULL))
> + break;
> + min += ESDHC_TUNE_CTRL_STEP;
> }
> - max += ESDHC_TUNE_CTRL_STEP;
> +
> + /* find the maxinum delay which can not pass tuning */
> + max = min + ESDHC_TUNE_CTRL_STEP;
> + while (max < ESDHC_TUNE_CTRL_MAX) {
> + esdhc_prepare_tuning(host, max);
> + if (mmc_send_tuning(host->mmc, opcode, NULL)) {
> + max -= ESDHC_TUNE_CTRL_STEP;
> + break;
> + }
> + max += ESDHC_TUNE_CTRL_STEP;
> + }
> +
> + win_length = max - min + 1;
> + /* get the largest pass window */
> + if (win_length > target_win_length) {
> + target_win_length = win_length;
> + target_min = min;
> + target_max = max;
> + }
> +
> + /* continue to find the next pass window */
> + min = max + ESDHC_TUNE_CTRL_STEP;
> }
>
> /* use average delay to get the best timing */
> - avg = (min + max) / 2;
> + avg = (target_min + target_max) / 2;
> esdhc_prepare_tuning(host, avg);
> ret = mmc_send_tuning(host->mmc, opcode, NULL);
> esdhc_post_tuning(host);
