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

On Mon, Dec 14, 2015 at 9:46 AM, Yang, York [off-list ref] wrote:

Hi, Carlo
        In 9faac7b95, tuning for DDR50 is enabled in mmc_sd_init_uhs_card(), so only SD card is affected.
        This is based on the SD spec version 3.01.
        mmc_sdio_init_uhs_card() is untouched. I don't know who add the code into mmc_sdio_init_uhs_card() and you may have a check on your side.

Hi Yang,
sorry for not being clear. Modifying mmc_sdio_init_uhs_card() was only
a test I did to check whether that could fix the issue, but it didn't.

Right now the situation is:
- In the latest master with commit 9faac7b95 WiFi is broken on the
ASUS X205TA (bcm43341)
- Reverting 9faac7b95 makes it working fine again

My conclusion is that issuing the CMD19 is basically breaking WiFi on
this platform.

-- 
Carlo Caione