This device has a Page size x8: 17,600 bytes (16,384 + 1216 bytes) and minimum required ECC 24-bit ECC per 1100 bytes of data. Spare area needed for ECC would be ECC * M, where M is (codeword <= 2^m-1). In this case M=14, because (1100*8)<=2^14-1, therefore minimum spare area needed is 14*24 = 336b or 42B per codeword. So for this device a minimum of 672bytes of the 1216 need to be used for ECC, the rest can be used for other purposes.
Jeff Lauruhn NAND Application Engineer -----Original Message----- From: linux-mtd [mailto:linux-mtd-boun...@lists.infradead.org] On Behalf Of Punnaiah Choudary Kalluri Sent: Thursday, March 19, 2015 1:50 AM To: dw...@infradead.org; computersforpe...@gmail.com Cc: linux-kernel@vger.kernel.org; shak...@xilinx.com; mich...@xilinx.com; linux-...@lists.infradead.org; kalluripunnaiahchoud...@gmail.com; Punnaiah Choudary Kalluri Subject: [PATCH] mtd: Expand the ecc placement locations to 1260 Device like MT29F32G08ABCDBJ4 have a writesize/oobsize of 16K/1260 Bytes. So, increasing the maximum ecc placement locations to 1260 Signed-off-by: Punnaiah Choudary Kalluri <punn...@xilinx.com> --- include/linux/mtd/mtd.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h index f17fa75..e73d85b 100644 --- a/include/linux/mtd/mtd.h +++ b/include/linux/mtd/mtd.h @@ -95,7 +95,7 @@ struct mtd_oob_ops { }; #define MTD_MAX_OOBFREE_ENTRIES_LARGE 32 -#define MTD_MAX_ECCPOS_ENTRIES_LARGE 640 +#define MTD_MAX_ECCPOS_ENTRIES_LARGE 1260 /* * Internal ECC layout control structure. For historical reasons, there is a * similar, smaller struct nand_ecclayout_user (in mtd-abi.h) that is retained -- 1.7.4 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
