MMCBLK CMD17/18 read data

Hello, I want to interface MMC card via SPI bus. However, I am getting CRC errors for CMD18. I tried reading partition table using CMD17 but still get errors. The same SDMMC card gets detected using SD interface. I want to compare the data of CMD18/CMD17 of SD and SPI modes. Please let me know how can I print the read data of the said commands in the block layer? I tried using the following code but it didn't help sg_copy_to_buffer(brq->data.sg, brq->data.sg_len, buf, 4096); and printed buf. Regards, Amit.