[U-Boot] [PATCH 3/4] Tegra114: MMC: Add SD bus power-rail init routine

[Stephen Warren]

On 03/12/2013 10:17 AM, Tom Warren wrote:
> T114 requires SD bus power-rail bringup for the SDIO card on SDMMC3.

> diff --git a/board/nvidia/dalmore/dalmore.c b/board/nvidia/dalmore/dalmore.c

> +#if defined(CONFIG_TEGRA_MMC)

It always is for Dalmore, right?

> +void board_sdmmc_voltage_init(void)

> +	/* TPS65913: LDO9_VOLTAGE = 3.3V */
> +	data_buffer[0] = 0x31;
> +	reg = 0x61;
> +
> +	for (i = 0; i < MAX_I2C_RETRY; ++i) {
> +		ret = i2c_write(PMU_I2C_ADDRESS, reg, 1, data_buffer, 1);
> +		if (ret) {
> +			udelay(100);
> +			printf("%s: PMU i2c_write %02X<-%02X returned %d\n",
> +				__func__, reg, data_buffer[0], ret);
> +		}
> +	}

Is there actually a need to retry these transactions; is there any
evidence they're expected to fail? Hopefully the HW isn't flaky like that.

AFAIK, the kernel driver for the PMIC doesn't retry these if they fail.
Hopefully it doesn't need to start doing so.