mmc: sdhci: do not try to use 3.3V signaling if not supported (1b5190c2) · Commits · 戴 / test

For eMMC devices it is valid to only support 1.8V signaling. When vqmmc is set to a fixed 1.8V regulator the stack tries to set 3.3V initially and prints the following warning: mmc1: Switching to 3.3V signalling voltage failed Clear the MMC_SIGNAL_VOLTAGE_330 flag in case 3.3V is signaling is not available. This prevents the stack from even trying to use 3.3V signaling and avoids the above warning. Signed-off-by:

Stefan Agner <stefan@agner.ch> Signed-off-by:

Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci.c

+8 −1

Original line number	Diff line number	Diff line
		@@ -3734,14 +3734,21 @@ int sdhci_setup_host(struct sdhci_host *host)
		mmc_gpio_get_cd(host->mmc) < 0)
		mmc->caps \|= MMC_CAP_NEEDS_POLL;

		/* If vqmmc regulator and no 1.8V signalling, then there's no UHS */
		if (!IS_ERR(mmc->supply.vqmmc)) {
		ret = regulator_enable(mmc->supply.vqmmc);

		/* If vqmmc provides no 1.8V signalling, then there's no UHS */
		if (!regulator_is_supported_voltage(mmc->supply.vqmmc, 1700000,
		1950000))
		host->caps1 &= ~(SDHCI_SUPPORT_SDR104 \|
		SDHCI_SUPPORT_SDR50 \|
		SDHCI_SUPPORT_DDR50);

		/* In eMMC case vqmmc might be a fixed 1.8V regulator */
		if (!regulator_is_supported_voltage(mmc->supply.vqmmc, 2700000,
		3600000))
		host->flags &= ~SDHCI_SIGNALING_330;

		if (ret) {
		pr_warn("%s: Failed to enable vqmmc regulator: %d\n",
		mmc_hostname(mmc), ret);

Admin message