Re: [PATCH 1/4] mmc: sdhci-cadence6: add PHY settle delay after tuning DLL re-lock

[Adrian Hunter]

On 22/09/2026 14:12, tze.yee.ng@xxxxxxxxxx wrote:
> From: Tze Yee Ng <tze.yee.ng@xxxxxxxxxx>
> 
> After re-locking the DLL, allow the same 5 to 5.5 ms for the clock and
> PHY signals to stabilize as sdhci_cdns6_phy_init() does. Without this
> settle time the command issued immediately after tuning (e.g. the R1b
> CMD6 that switches eMMC from HS200 down to HS during HS400 selection)
> can time out.
> 
> Signed-off-by: Tze Yee Ng <tze.yee.ng@xxxxxxxxxx>

Presume you realize the delay is inside the tuning loop, so 40x 5ms
is 200ms total.

Nevertheless:

Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>

> ---
>  drivers/mmc/host/sdhci-cadence-phy-v6.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci-cadence-phy-v6.c b/drivers/mmc/host/sdhci-cadence-phy-v6.c
> index 22d56bb46d75..35f35ef9c710 100644
> --- a/drivers/mmc/host/sdhci-cadence-phy-v6.c
> +++ b/drivers/mmc/host/sdhci-cadence-phy-v6.c
> @@ -811,6 +811,9 @@ int sdhci_cdns6_set_tune_val(struct sdhci_host *host, unsigned int val)
>  	if (ret)
>  		dev_warn(mmc_dev(host->mmc), "%s: DLL reset release failed: %d\n", __func__, ret);
>  
> +	/* Allow 5 to 5.5 ms for clock and PHY signals to stabilize after configuration */
> +	usleep_range(5000, 5500);
> +
>  	return ret;
>  }
>