switch (mtd->writesize) {
        case 2048:
        case 4096:
+       case 8192:
                host->pmecc_degree = (sector_size == 512) ?
                        PMECC_GF_DIMENSION_13 : PMECC_GF_DIMENSION_14;
                host->pmecc_cw_len = (1 << host->pmecc_degree) - 1;
                nand->ecc.steps = 1;
                nand->ecc.bytes = host->pmecc_bytes_per_sector *
                                       host->pmecc_sector_number;
+
+               if (nand->ecc.bytes > MTD_MAX_ECCPOS_ENTRIES_LARGE) {
+                       dev_err(host->dev, "too large eccpos entries. max support ecc.bytes is %d\n",
+                                       MTD_MAX_ECCPOS_ENTRIES_LARGE);
+                       return -EINVAL;
+               }
+
                if (nand->ecc.bytes > mtd->oobsize - 2) {
                        printk(KERN_ERR "No room for ECC bytes\n");
                        return -EINVAL;
 #ifdef CONFIG_SYS_NAND_READY_PIN
        nand->dev_ready = at91_nand_ready;
 #endif
-       nand->chip_delay = 20;
+       nand->chip_delay = 75;
 
        ret = nand_scan_ident(mtd, CONFIG_SYS_NAND_MAX_CHIPS, NULL);
        if (ret)