Re: [PATCH 3/4] mmc: mmc: enable ios.enhanced_strobe before mmc_set_timing

Shawn Lin
2016-12-26T07:12:57Z

On 2016/12/23 17:18, Ritesh Harjani wrote:
> Hi Shawn,
>
> Do you think, below change should be fine?

yes.

> I am still checking on what we discussed on Patch2.
>
> why I am asking is because - for HS400 in SDHC-MSM, we do the DLL
> re-calibration as per the HW sequence. So it is done in both the cases,
> for HS400 mode without and with enhanced strobe mode.
>
> This can be done as part of set_ios when mmc_set_timing is called in
> sdhci-msm driver.
>
> I am still trying to check more on what would be more generic and
> appropriate way inside sdhci-msm, for that I would like to know if
> ios.enhanced_strobe = true before calling mmc_set_timing should be
> acceptable or not ?
>

Sure.

>
> Regards
> Ritesh
>
> On 12/20/2016 11:23 AM, Ritesh Harjani wrote:
>> Some controllers may need to configure few registers based on enhanced
>> strobe mode while configuring to HS400 timing, thus make
>> ios.enhanced_strobe to true before mmc_set_timing in mmc_select_hs400es.
>>
>> Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>
>> ---
>> drivers/mmc/core/mmc.c | 8 +++++++-
>> 1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
>> index eb69497..052368e 100644
>> --- a/drivers/mmc/core/mmc.c
>> +++ b/drivers/mmc/core/mmc.c
>> @@ -1327,12 +1327,18 @@ static int mmc_select_hs400es(struct mmc_card
>> *card)
>> goto out_err;
>> }
>>
>> + /*
>> + * Enable enhanced_strobe in ios, as some controllers
>> + * may need to configure few registers based on enhanced
>> + * strobe while changing HS400 timing.
>> + */
>> + host->ios.enhanced_strobe = true;
>> +
>> /* Set host controller to HS400 timing and frequency */
>> mmc_set_timing(host, MMC_TIMING_MMC_HS400);
>> mmc_set_bus_speed(card);
>>
>> /* Controller enable enhanced strobe function */
>> - host->ios.enhanced_strobe = true;
>> if (host->ops->hs400_enhanced_strobe)
>> host->ops->hs400_enhanced_strobe(host, &host->ios);
>>
>>
>

--
Best Regards
Shawn Lin