[PATCH] mmc: display an error number to debug

[Stephen Warren]

On 11/6/20 4:23 AM, Jaehoon Chung wrote:
> It's useful to know an error number when it's debugging.

> diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c

> @@ -2746,7 +2746,7 @@ static int mmc_power_on(struct mmc *mmc)
>  		int ret = regulator_set_enable(mmc->vmmc_supply, true);
>  
>  		if (ret) {
> -			puts("Error enabling VMMC supply\n");
> +			puts("Error enabling VMMC supply : %d\n", ret);

At least this one needs to be printf() not puts(). This causes build
failures for any board that compiles this code, i.e. anything with the
following enabled:

static int mmc_power_on(struct mmc *mmc)
{
#if CONFIG_IS_ENABLED(DM_MMC) && CONFIG_IS_ENABLED(DM_REGULATOR)