Re: [PATCH 6/6] mmc: sdhci-esdhc-imx: switch standard tuning to manual tuning

[Adrian Hunter <adrian.hunter@intel.com>]

On 9/04/25 10:55, ziniu.wang_1@nxp.com wrote:
> From: Luke Wang <ziniu.wang_1@nxp.com>
> 
> Current standard tuning has some limitations:
> 
> 1. Standard tuning only try 40 times to find first pass window, but this
> pass window maybe not the best pass window.
> 
> 2. Sometimes there are two tuning pass windows and the gap between
> those two windows may only have one cell. If tuning step > 1, the gap may
> just be skipped and host assumes those two windows as a continuous
> windows. This will cause a bad delay cell near the gap to be selected.
> 
> 3. Standard tuning logic need to detect at least one success and failure
> to pass the tuning. If all cells in the tuning window pass, the hardware
> will not set the SDHCI_CTRL_TUNED_CLK bit, causing tuning failed.
> 
> 4. Standard tuning logic only check the CRC, do not really compare the data
> pattern. If data pins are connected incorrectly, standard will not detect
> this kind of issue.
> 
> Switch to manual tuning to avoid those limitations

Is it necessary to have standard tuning at all then?

> 
> Signed-off-by: Luke Wang <ziniu.wang_1@nxp.com>
> ---
>  drivers/mmc/host/sdhci-esdhc-imx.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
> index fd0ad0ad1519..9b66e07ed8e7 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -275,35 +275,35 @@ static const struct esdhc_soc_data usdhc_imx6q_data = {
>  };
>  
>  static const struct esdhc_soc_data usdhc_imx6sl_data = {
> -	.flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_STD_TUNING
> +	.flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_MAN_TUNING
>  			| ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_ERR004536
>  			| ESDHC_FLAG_HS200
>  			| ESDHC_FLAG_BROKEN_AUTO_CMD23,
>  };
>  
>  static const struct esdhc_soc_data usdhc_imx6sll_data = {
> -	.flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_STD_TUNING
> +	.flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_MAN_TUNING
>  			| ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_HS200
>  			| ESDHC_FLAG_HS400
>  			| ESDHC_FLAG_STATE_LOST_IN_LPMODE,
>  };
>  
>  static const struct esdhc_soc_data usdhc_imx6sx_data = {
> -	.flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_STD_TUNING
> +	.flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_MAN_TUNING
>  			| ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_HS200
>  			| ESDHC_FLAG_STATE_LOST_IN_LPMODE
>  			| ESDHC_FLAG_BROKEN_AUTO_CMD23,
>  };
>  
>  static const struct esdhc_soc_data usdhc_imx6ull_data = {
> -	.flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_STD_TUNING
> +	.flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_MAN_TUNING
>  			| ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_HS200
>  			| ESDHC_FLAG_ERR010450
>  			| ESDHC_FLAG_STATE_LOST_IN_LPMODE,
>  };
>  
>  static const struct esdhc_soc_data usdhc_imx7d_data = {
> -	.flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_STD_TUNING
> +	.flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_MAN_TUNING
>  			| ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_HS200
>  			| ESDHC_FLAG_HS400
>  			| ESDHC_FLAG_STATE_LOST_IN_LPMODE
> @@ -319,7 +319,7 @@ static struct esdhc_soc_data usdhc_s32g2_data = {
>  };
>  
>  static struct esdhc_soc_data usdhc_imx7ulp_data = {
> -	.flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_STD_TUNING
> +	.flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_MAN_TUNING
>  			| ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_HS200
>  			| ESDHC_FLAG_PMQOS | ESDHC_FLAG_HS400
>  			| ESDHC_FLAG_STATE_LOST_IN_LPMODE,
> @@ -332,7 +332,7 @@ static struct esdhc_soc_data usdhc_imxrt1050_data = {
>  };
>  
>  static struct esdhc_soc_data usdhc_imx8qxp_data = {
> -	.flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_STD_TUNING
> +	.flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_MAN_TUNING
>  			| ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_HS200
>  			| ESDHC_FLAG_HS400 | ESDHC_FLAG_HS400_ES
>  			| ESDHC_FLAG_STATE_LOST_IN_LPMODE
> @@ -341,7 +341,7 @@ static struct esdhc_soc_data usdhc_imx8qxp_data = {
>  };
>  
>  static struct esdhc_soc_data usdhc_imx8mm_data = {
> -	.flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_STD_TUNING
> +	.flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_MAN_TUNING
>  			| ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_HS200
>  			| ESDHC_FLAG_HS400 | ESDHC_FLAG_HS400_ES
>  			| ESDHC_FLAG_STATE_LOST_IN_LPMODE,