In L2.6.35_11.09.01_ER BSP Uboot, the MMC driver was updated, but there is issue that when you modified some uboot code, the MMC driver has chance to fail to work.
The root cause is that mmc->has_init hasn't been initialized. Sometimes the value will be not zero, then mmc driver will be skipped for initialization. Attached is the patch to fix this issue in L2.6.35_11.09.01_ER BSP Uboot.