Commit b08e1f63 authored by Pekon Gupta's avatar Pekon Gupta Committed by Brian Norris
Browse files

mtd: nand: omap: ecc.correct: omap_elm_correct_data: cleanup for future enhancements 



Current omap_elm_correct_data() code is not scalable for future ecc-schemes
due to presence of tweaks and hard-coded macros for BCH4_ECC and BCH8_ECC
ecc-schemes at multiple places.

This patch:
 - replaces 'ecc_opt' with '(info->nand.ecc.strength == BCH8_MAX_ERROR)
   used to differentiate between BCH8_HW and BCH4_SW
 - replaces macros (defining magic number for specific ecc-scheme) with
   generic variables
 - removes dependency on macros defined in elm.h (like BCHx_ECC_OOB_BYTES)

Tested-by: default avatarStefan Roese <sr@denx.de>
Signed-off-by: default avatarPekon Gupta <pekon@ti.com>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
parent 78f43c53

drivers/mtd/nand/omap2.c

+13 −25
Original line number Diff line number Diff line
@@ -118,14 +118,9 @@ 


#define OMAP24XX_DMA_GPMC		4



#define BCH8_MAX_ERROR		8	/* upto 8 bit correctable */

#define BCH4_MAX_ERROR		4	/* upto 4 bit correctable */



#define SECTOR_BYTES		512

/* 4 bit padding to make byte aligned, 56 = 52 + 4 */

#define BCH4_BIT_PAD		4

#define BCH8_ECC_MAX		((SECTOR_BYTES + BCH8_ECC_OOB_BYTES) * 8)

#define BCH4_ECC_MAX		((SECTOR_BYTES + BCH4_ECC_OOB_BYTES) * 8)



/* GPMC ecc engine settings for read */

#define BCH_WRAPMODE_1		1	/* BCH wrap mode 1 */
@@ -1356,8 +1351,8 @@ static int omap_elm_correct_data(struct mtd_info *mtd, u_char *data, 
	u_char *erased_ecc_vec;

	u_char *buf;

	int bitflip_count;

	enum bch_ecc type;

	bool is_error_reported = false;

	u32 bit_pos, byte_pos, error_max, pos;



	switch (info->ecc_opt) {

	case OMAP_ECC_BCH4_CODE_HW:
@@ -1378,12 +1373,6 @@ static int omap_elm_correct_data(struct mtd_info *mtd, u_char *data, 
	/* Initialize elm error vector to zero */

	memset(err_vec, 0, sizeof(err_vec));



	if (info->nand.ecc.strength == BCH8_MAX_ERROR) {

		type = BCH8_ECC;

	} else {

		type = BCH4_ECC;

	}



	for (i = 0; i < eccsteps ; i++) {

		eccflag = 0;	/* initialize eccflag */
@@ -1448,20 +1437,19 @@ static int omap_elm_correct_data(struct mtd_info *mtd, u_char *data, 
	for (i = 0; i < eccsteps; i++) {

		if (err_vec[i].error_reported) {

			for (j = 0; j < err_vec[i].error_count; j++) {

				u32 bit_pos, byte_pos, error_max, pos;



				if (type == BCH8_ECC)

					error_max = BCH8_ECC_MAX;

				else

					error_max = BCH4_ECC_MAX;



				if (info->nand.ecc.strength == BCH8_MAX_ERROR)

					pos = err_vec[i].error_loc[j];

				else

					/* Add 4 to take care 4 bit padding */

				switch (info->ecc_opt) {

				case OMAP_ECC_BCH4_CODE_HW:

					/* Add 4 bits to take care of padding */

					pos = err_vec[i].error_loc[j] +

						BCH4_BIT_PAD;



					break;

				case OMAP_ECC_BCH8_CODE_HW:

					pos = err_vec[i].error_loc[j];

					break;

				default:

					return -EINVAL;

				}

				error_max = (ecc->size + actual_eccbytes) * 8;

				/* Calculate bit position of error */

				bit_pos = pos % 8;
@@ -1483,7 +1471,7 @@ static int omap_elm_correct_data(struct mtd_info *mtd, u_char *data, 
		stat += err_vec[i].error_count;



		/* Update page data with sector size */

		data += info->nand.ecc.size;

		data += ecc->size;

		spare_ecc += ecc->bytes;

	}

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