Adding the debug message between SD/eMMC device and host in u-boot.

Sometimes you encoutner thisSD/eMMC issue ,"Card did notrespond to voltage select! ". You could add debug message to see the communication between SD/eMMC and host.

#define DEBUG

#define CONFIG_MMC_TRACE

& add debug message in mmc.c (driver/mmc)

int mmc_send_cmd(struct mmc
*mmc, struct mmc_cmd *cmd, struct mmc_data *data)

{

printf("CMD_SEND:%d\n",cmd->cmdidx);

printf("\t\tARG\t\t\t0x%08X\n", cmd->cmdarg);

}

=> mmcinfo

CMD_SEND:0

ARG
0x00000000
MMC_RSP_NONE

CMD_SEND:8
ARG
0x000001AA
MMC_RSP_R1,5,6,7
0x00000001

CMD_SEND:55

ARG
0x00000000

MMC_RSP_R1,5,6,7 0x00000001

CMD_SEND:0

ARG
0x00000000

MMC_RSP_NONE