[PATCH 1/2] mmc: core: enable CMD19 tuning for DDR50 mode

[Jaehoon Chung]

Hi,

On 12/14/2015 07:56 PM, Carlo Caione wrote:
> On Mon, Dec 14, 2015 at 10:24 AM, Yang, York <weijuny at qti.qualcomm.com> wrote:
>> Hi, Carlo
>>
>>         I don't think so. You may check the 9faac7b95, there are two changes in sd.c and sdhc.c.
>>         Surely the change in sdhc.c will not affect ASUS X205TA (bcm43341) since it is a SDIO device.
>>         Actually the calling sequence is this: mmc_sd_init_uhs_card() calls sdhci_execute_tuning(). In 9faac7b95, I enabled tuning for DDR50 in these two functions.
>>         If your function calling sequence is mmc_sdio_init_uhs_card()->sdhci_execute_tuning(), the tuning will not carried out, since you didn't enable tuning for DDR50 in mmc_sdio_init_uhs_card().
>>         Unless you call sdhci_execute_tuning directly, the tuning command may go through be sent out.
> 
> Hi Yang,
> 
> On the unmodified master what I see is:
> 
> - mmc_sdio_init_uhs_card() is called
> - card->sw_caps.sd3_bus_mode is 0x14
> - card->sw_caps.sd3_bus_mode & SD_MODE_UHS_SDR50 is actually verified
> (even though the tuning for DDR50 is not enabled)
> - mmc_execute_tuning() is actually called

As i know, When mode is UHS_SDR50, tuning is not mandatory.
Even though i need to check the spec file, i think that condition check is strange.

Best Regards,
Jaehoon Chung

>