mmc_blk_part_switch
if (mmc_blk_part_switch(host->card, md->part_type))
mmc_blk_part_switch(card, 0);
static inline int mmc_blk_part_switch(struct mmc_card *card,
ret = mmc_blk_part_switch(card, md->part_type);
mmc_blk_part_switch(card, md->part_type);
err = mmc_blk_part_switch(card, target_part);