| 1 | From 93ad1a19872dfa2f4b9aa7b8d20581bda3057622 Mon Sep 17 00:00:00 2001 |
| 2 | From: Lars-Peter Clausen <lars@metafoo.de> |
| 3 | Date: Sat, 26 Feb 2011 15:30:07 +0100 |
| 4 | Subject: [PATCH 2/4] NAND: Optimize NAND_ECC_HW_OOB_FIRST read |
| 5 | |
| 6 | Avoid sending unnecessary READ commands to the chip. |
| 7 | --- |
| 8 | drivers/mtd/nand/nand_base.c | 15 +++++++++++---- |
| 9 | 1 files changed, 11 insertions(+), 4 deletions(-) |
| 10 | |
| 11 | --- a/drivers/mtd/nand/nand_base.c |
| 12 | +++ b/drivers/mtd/nand/nand_base.c |
| 13 | @@ -1008,9 +1008,16 @@ static int nand_read_page_hwecc_oob_firs |
| 14 | uint8_t *ecc_calc = chip->buffers->ecccalc; |
| 15 | |
| 16 | /* Read the OOB area first */ |
| 17 | - chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page); |
| 18 | - chip->read_buf(mtd, chip->oob_poi, mtd->oobsize); |
| 19 | - chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page); |
| 20 | + /* Read the OOB area first */ |
| 21 | + if (mtd->writesize > 512) { |
| 22 | + chip->cmdfunc(mtd, NAND_CMD_READ0, mtd->writesize, page); |
| 23 | + chip->read_buf(mtd, chip->oob_poi, mtd->oobsize); |
| 24 | + chip->cmdfunc(mtd, NAND_CMD_RNDOUT, 0, -1); |
| 25 | + } else { |
| 26 | + chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page); |
| 27 | + chip->read_buf(mtd, chip->oob_poi, mtd->oobsize); |
| 28 | + chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page); |
| 29 | + } |
| 30 | |
| 31 | for (i = 0; i < chip->ecc.total; i++) |
| 32 | ecc_code[i] = chip->oob_poi[eccpos[i]]; |
| 33 | @@ -1177,7 +1184,7 @@ static int nand_do_read_ops(struct mtd_i |
| 34 | if (realpage != chip->pagebuf || oob) { |
| 35 | bufpoi = aligned ? buf : chip->buffers->databuf; |
| 36 | |
| 37 | - if (likely(sndcmd)) { |
| 38 | + if (likely(sndcmd) && chip->ecc.mode != NAND_ECC_HW_OOB_FIRST) { |
| 39 | chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page); |
| 40 | sndcmd = 0; |
| 41 | } |
| 42 | |
