[PATCH v1] Revert "mmc: mmc-uclass: Use max-frequency from device tree with default handling"

[Marek Vasut]

On 1/8/26 12:40 PM, Tanmay Kathpalia wrote:
> This reverts commit aebb523a23818a8ee4199c9532b51e3d4020696f.
> 
> The change to use dev_read_u32_default() with a default value of 0
> causes regression for host controller drivers that hardcode f_max
> before calling mmc_of_parse().
> 
> When the "max-frequency" property is not specified in the device tree,
> dev_read_u32_default() returns 0, which overwrites the previously
> configured f_max value set by the driver. This effectively resets
> the maximum frequency to 0, breaking MMC functionality for those
> controllers.
> 
> Revert to the original dev_read_u32() behavior which only updates
> cfg->f_max when the "max-frequency" property is explicitly present
> in the device tree, preserving driver-configured values otherwise.
> 
> Signed-off-by: Tanmay Kathpalia <tanmay.kathpalia at altera.com>
> ---
>   drivers/mmc/mmc-uclass.c | 9 ++-------
>   1 file changed, 2 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/mmc/mmc-uclass.c b/drivers/mmc/mmc-uclass.c
> index bf0bea93853..2f4dc5bd887 100644
> --- a/drivers/mmc/mmc-uclass.c
> +++ b/drivers/mmc/mmc-uclass.c
> @@ -243,13 +243,8 @@ int mmc_of_parse(struct udevice *dev, struct mmc_config *cfg)
>   		return -EINVAL;
>   	}
>   
> -	/*
> -	 * Maximum frequency is obtained from the optional "max-frequency" property.
> -	 * If not specified in device tree, defaults to 0 and sdhci_setup_cfg()
> -	 * will set the MMC configuration maximum frequency to the host controller's
> -	 * maximum base clock frequency from capabilities register.
> -	 */
> -	cfg->f_max = dev_read_u32_default(dev, "max-frequency", 0);
> +	/* f_max is obtained from the optional "max-frequency" property */
> +	dev_read_u32(dev, "max-frequency", &cfg->f_max);

Why not do this then ?

cfg->f_max = dev_read_u32_default(dev, "max-frequency", cfg->f_max);