data.dest = (char *)ext_csd;
        data.blocks = 1;
-       data.blocksize = 512;
+       data.blocksize = MMC_MAX_BLOCK_LEN;
        data.flags = MMC_DATA_READ;
 
        err = mmc_send_cmd(mmc, &cmd, &data);
 
 static int mmc_change_freq(struct mmc *mmc)
 {
-       ALLOC_CACHE_ALIGN_BUFFER(u8, ext_csd, 512);
+       ALLOC_CACHE_ALIGN_BUFFER(u8, ext_csd, MMC_MAX_BLOCK_LEN);
        char cardtype;
        int err;
 
        uint mult, freq;
        u64 cmult, csize, capacity;
        struct mmc_cmd cmd;
-       ALLOC_CACHE_ALIGN_BUFFER(u8, ext_csd, 512);
-       ALLOC_CACHE_ALIGN_BUFFER(u8, test_csd, 512);
+       ALLOC_CACHE_ALIGN_BUFFER(u8, ext_csd, MMC_MAX_BLOCK_LEN);
+       ALLOC_CACHE_ALIGN_BUFFER(u8, test_csd, MMC_MAX_BLOCK_LEN);
        int timeout = 1000;
 
 #ifdef CONFIG_MMC_SPI_CRC_ON
        mmc->capacity = (csize + 1) << (cmult + 2);
        mmc->capacity *= mmc->read_bl_len;
 
-       if (mmc->read_bl_len > 512)
-               mmc->read_bl_len = 512;
+       if (mmc->read_bl_len > MMC_MAX_BLOCK_LEN)
+               mmc->read_bl_len = MMC_MAX_BLOCK_LEN;
 
-       if (mmc->write_bl_len > 512)
-               mmc->write_bl_len = 512;
+       if (mmc->write_bl_len > MMC_MAX_BLOCK_LEN)
+               mmc->write_bl_len = MMC_MAX_BLOCK_LEN;
 
        /* Select the card, and put it into Transfer Mode */
        if (!mmc_host_is_spi(mmc)) { /* cmd not supported in spi */
                                        | ext_csd[EXT_CSD_SEC_CNT + 1] << 8
                                        | ext_csd[EXT_CSD_SEC_CNT + 2] << 16
                                        | ext_csd[EXT_CSD_SEC_CNT + 3] << 24;
-                       capacity *= 512;
+                       capacity *= MMC_MAX_BLOCK_LEN;
                        if ((capacity >> 20) > 2 * 1024)
                                mmc->capacity = capacity;
                }
                 * group size from ext_csd directly, or calculate
                 * the group size from the csd value.
                 */
-               if (ext_csd[EXT_CSD_ERASE_GROUP_DEF])
+               if (ext_csd[EXT_CSD_ERASE_GROUP_DEF]) {
                        mmc->erase_grp_size =
-                             ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE] * 512 * 1024;
-               else {
+                               ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE] *
+                                       MMC_MAX_BLOCK_LEN * 1024;
+               } else {
                        int erase_gsz, erase_gmul;
                        erase_gsz = (mmc->csd[2] & 0x00007c00) >> 10;
                        erase_gmul = (mmc->csd[2] & 0x000003e0) >> 5;