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

On Mon, Dec 14, 2015 at 10:24 AM, Yang, York [off-list ref] 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

-- 
Carlo Caione