Hi Jaehoon, Thanks for replying promptly. adding more debug prints I see that CMD9(CSD) CMD51(SSR) values in case of SD and SPI mode are the same. Only command that troubles is CMD18. My clock setting is 25Mhz and the card is working at 3.3V. Regards, Amit. On Wed, Feb 1, 2017 at 1:38 PM, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> wrote: > Hi, > > On 02/01/2017 04:23 PM, amit mahadik wrote: >> 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? > > In my experience, CRC error was timing issue..(clock, driver-strength, etc..) > You can check those things. > > Best Regards, > Jaehoon Chung > >> >> 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. >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html