On 10/29/2012 06:08 PM, Seungwon Jeon wrote:
> Monday, October 29, 2012, Jaehoon Chung <jh80.ch...@samsung.com>
>> After power-on, must be ensured at least 74~80 clocks before sending any
>> first command.
>> To ensure, it's good that dw_mci_setup_bus() is located at dw_mci_set_ios
>> instead of __dw_mci_start_request()
> After power-up, host driver sets 'DW_MMC_CARD_NEED_INIT' flag, right?
> And then, this flag help to add SDMMC_CMD_INIT flag into CMD, when
> __dw_mci_start_request is executed.
> 74~80 clocks is ensured with SDMMC_CMD_INIT regardless location change, isn't
> it?
> I mentioned this part in previous mail. Could you check it?
According to eMMC spec, after power-on, need to wait for 74-clock before
sending first command
You can see code that after mmc_set_ios(), waiting for mmc_delay(10) into
mmc_power_up().
(You can read the comment at mmc_power_up(), Maybe mmc_delay(10) didn't ensure
the 74-clock).
Best Regards,
Jaehoon Chung
>
> Thanks,
> Seungwon Jeon
>
>>
>> Signed-off-by: Jaehoon Chung <jh80.ch...@samsung.com>
>> Signed-off-by: Kyungmin Park <kyungmin.p...@samsung.com>
>> Acked-by: Seungwon Jeon <tgih....@samsung.com>
>> ------
>> Changelog V2:
>> - Modified the commit-message.
>> ---
>> drivers/mmc/host/dw_mmc.c | 6 +++---
>> 1 files changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>> index 4b2bedc..de79093 100644
>> --- a/drivers/mmc/host/dw_mmc.c
>> +++ b/drivers/mmc/host/dw_mmc.c
>> @@ -682,9 +682,6 @@ static void __dw_mci_start_request(struct dw_mci *host,
>> if (host->pdata->select_slot)
>> host->pdata->select_slot(slot->id);
>>
>> - /* Slot specific timing and width adjustment */
>> - dw_mci_setup_bus(slot);
>> -
>> host->cur_slot = slot;
>> host->mrq = mrq;
>>
>> @@ -810,6 +807,9 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct
>> mmc_ios *ios)
>> if (slot->host->drv_data->set_ios)
>> slot->host->drv_data->set_ios(slot->host, ios);
>>
>> + /* Slot specific timing and width adjustment */
>> + dw_mci_setup_bus(slot);
>> +
>> switch (ios->power_mode) {
>> case MMC_POWER_UP:
>> set_bit(DW_MMC_CARD_NEED_INIT, &slot->flags);
>> --
>> 1.7.4.1
>> --
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