Dear Seungwon, On 10/30/2012 02:27 PM, Seungwon Jeon wrote: > Monday, October 29, 2012, Jaehoon Chung <[email protected]> wrote: >> On 10/29/2012 06:08 PM, Seungwon Jeon wrote: >>> Monday, October 29, 2012, Jaehoon Chung <[email protected]> >>>> 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). > There is 'send_initialization' bit in CMD register. > If this bit set with CMD0, it will guarantee 80 clocks by host controller. Is it guaranteed 80-clocks by host-controller? So I understood something wrong. My understanding is that "if flags is set, need to wait for 80-clock." If host-controller can ensure the 80-clock, location is not important.
My point was just entire sequence with core.c and dw_mmc.c Anyway, thank you for review. If i miss other thing. let me know, plz. Best Regards, Jaehoon Chung > Currently this is applied in driver. > I agree change the location of dw_mci_setup_bus. > But commit message seem not proper for it. > Please let me know, if I miss something. > > Thanks, > Seungwon Jeon >> >> Best Regards, >> Jaehoon Chung >>> >>> Thanks, >>> Seungwon Jeon >>> >>>> >>>> Signed-off-by: Jaehoon Chung <[email protected]> >>>> Signed-off-by: Kyungmin Park <[email protected]> >>>> Acked-by: Seungwon Jeon <[email protected]> >>>> ------ >>>> 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 >>>> -- >>>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in >>>> the body of a message to [email protected] >>>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in >>> the body of a message to [email protected] >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in >> the body of a message to [email protected] >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
