Re: [PATCH] mmc: core: Fixup suspend/resume issues for UHS-I cards

[Subhash Jadavani <subhashj@codeaurora.org>]

Tested-by: Subhash Jadavani <subhashj@codeaurora.org>

On 3/2/2012 12:27 AM, Philip Rakity wrote:
> acked-by: Philip Rakity<prakity@marvell.com>
>
> On Mar 1, 2012, at 4:18 AM, Ulf Hansson wrote:
>
>> Even if cards supports 1.8V I/O voltage those should anyway be
>> initialized at 3.3V I/O according to (e)MMC, SD and SDIO specs.
>> Some eMMC and embedded SDIO devices are able to be initialized
>> at 1.8V as well, but it is better to be safe.
>>
>> Do note that initialization in this context means that the card
>> has been completely powered off, otherwise the card will remain
>> at the last I/O voltage level that were negotitiated.
>>
>> Due to the above being taken care of the suspend/resume issues
>> for UHS-I SD-cards has been fixed.
>>
>> Change-Id: Ia906f69d44b5be8374b0b536881190f67757b03e
>> Signed-off-by: Ulf Hansson<ulf.hansson@stericsson.com>
>> ---
>> drivers/mmc/core/core.c |    3 +++
>> drivers/mmc/core/mmc.c  |    3 +++
>> drivers/mmc/core/sd.c   |    8 +++-----
>> drivers/mmc/core/sdio.c |    9 +++++++++
>> 4 files changed, 18 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
>> index 0b317f0..faa0af1 100644
>> --- a/drivers/mmc/core/core.c
>> +++ b/drivers/mmc/core/core.c
>> @@ -2074,6 +2074,9 @@ static int mmc_rescan_try_freq(struct mmc_host *host, unsigned freq)
>> 	 */
>> 	mmc_hw_reset_for_init(host);
>>
>> +	/* Initialization should be done at 3.3 V I/O voltage. */
>> +	mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330, 0);
>> +
>> 	/*
>> 	 * sdio_reset sends CMD52 to reset card.  Since we do not know
>> 	 * if the card is being re-initialized, just send it.  CMD52
>> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
>> index 6b13776..6defddd 100644
>> --- a/drivers/mmc/core/mmc.c
>> +++ b/drivers/mmc/core/mmc.c
>> @@ -830,6 +830,9 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>> 	if (!mmc_host_is_spi(host))
>> 		mmc_set_bus_mode(host, MMC_BUSMODE_OPENDRAIN);
>>
>> +	/* Initialization should be done at 3.3 V I/O voltage. */
>> +	mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330, 0);
>> +
>> 	/*
>> 	 * Since we're changing the OCR value, we seem to
>> 	 * need to tell some cards to go back to the idle
>> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
>> index 5017f93..c272c686 100644
>> --- a/drivers/mmc/core/sd.c
>> +++ b/drivers/mmc/core/sd.c
>> @@ -911,6 +911,9 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
>> 	BUG_ON(!host);
>> 	WARN_ON(!host->claimed);
>>
>> +	/* The initialization should be done at 3.3 V I/O voltage. */
>> +	mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330, 0);
>> +
>> 	err = mmc_sd_get_cid(host, ocr, cid,&rocr);
>> 	if (err)
>> 		return err;
>> @@ -1156,11 +1159,6 @@ int mmc_attach_sd(struct mmc_host *host)
>> 	BUG_ON(!host);
>> 	WARN_ON(!host->claimed);
>>
>> -	/* Make sure we are at 3.3V signalling voltage */
>> -	err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330, false);
>> -	if (err)
>> -		return err;
>> -
>> 	/* Disable preset value enable if already set since last time */
>> 	if (host->ops->enable_preset_value) {
>> 		mmc_host_clk_hold(host);
>> diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
>> index 12cde6e..dac2e23 100644
>> --- a/drivers/mmc/core/sdio.c
>> +++ b/drivers/mmc/core/sdio.c
>> @@ -585,6 +585,10 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
>> 	 * Inform the card of the voltage
>> 	 */
>> 	if (!powered_resume) {
>> +
>> +		/* The initialization should be done at 3.3 V I/O voltage. */
>> +		mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330, 0);
>> +
>> 		err = mmc_send_io_op_cond(host, host->ocr,&ocr);
>> 		if (err)
>> 			goto err;
>> @@ -996,6 +1000,11 @@ static int mmc_sdio_power_restore(struct mmc_host *host)
>> 	 * With these steps taken, mmc_select_voltage() is also required to
>> 	 * restore the correct voltage setting of the card.
>> 	 */
>> +
>> +	if (!mmc_card_keep_power(host))
>> +		/* The initialization should be done at 3.3 V I/O voltage. */
>> +		mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330, 0);
>> +
>> 	sdio_reset(host);
>> 	mmc_go_idle(host);
>> 	mmc_send_if_cond(host, host->ocr_avail);
>> -- 
>> 1.7.7.2
>>
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