Re: [PATCH] mmc: host: sdhci. UHS Switch failure - cycle power if regulator is used

[Aaron Lu <aaron.lu@amd.com>]

On 06/28/2012 12:15 AM, philipspatches@gmail.com wrote:
> From: Philip Rakity<prakity@marvell.com>
>
> Power needs to be removed from the card when switching to 1.8v fails.
>
> If a regulator is used to control vmmc we need to turn the
> regulator off and then back on otherwise power will not be removed
> from the card.

Reviewed-by: Aaron Lu <aaron.lu@amd.com>

-Aaron

>
> Signed-off-by: Philip Rakity<prakity@marvell.com>
> ---
>   drivers/mmc/host/sdhci.c |    4 ++++
>   1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index f4b8b4d..ef4231a 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1663,11 +1663,15 @@ static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host,
>   		pwr = sdhci_readb(host, SDHCI_POWER_CONTROL);
>   		pwr&= ~SDHCI_POWER_ON;
>   		sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);
> +		if (host->vmmc)
> +			regulator_disable(host->vmmc);
>
>   		/* Wait for 1ms as per the spec */
>   		usleep_range(1000, 1500);
>   		pwr |= SDHCI_POWER_ON;
>   		sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);
> +		if (host->vmmc)
> +			regulator_enable(host->vmmc);
>
>   		pr_info(DRIVER_NAME ": Switching to 1.8V signalling "
>   			"voltage failed, retrying with S18R set to 0\n");