[U-Boot] Revert "mmc: retry the cmd8 to meet 74 clocks requirement in the spec"

[Stephen Warren]

On 01/-10/-28163 12:59 PM, Macpaul Lin wrote:
> This reverts commit 02f3029f1810b99869254d0cf0a71946a008a728.
> 
> This patch add 3 times retry to CMD8 because the Marvell mmc controller
> doesn't obey the power ramp up process in the SD specification 6.4.1.
> (Please refer to figure 6.1 and 6.2 in the specification.)
> 
> The CMD0 should be send after power ramp up has been finished.
> However, the Marvell mmc contorller must do power ramp up after the
> first CMD0 command has been send.
> 
> This patch also affect existing platforms like Nokia N900 and other
> platforms.
> 
> Signed-off-by: Macpaul Lin <macpaul at andestech.com>
> Acked-by: Lei Wen <leiwen at marvell.com>

Acked-by: Stephen Warren <swarren at nvidia.com>
Tested-by: Stephen Warren <swarren at nvidia.com>

As background, I'm working on patches to support the Toshiba AC100 /
Dynabook AZ in mainline U-Boot. The internal MMC didn't work at all
until this revert was applied. The SD slot worked perfectly though. I
guess this is related to the MMC itself not supporting this
(SD-specific?) command, and the patch caused MMC mode never to be attempted.