From aa6d01fa435a6f701128829f8d9d04208fd53176 Mon Sep 17 00:00:00 2001 From: Mike Dunn Date: Wed, 11 Jul 2012 11:08:19 -0700 Subject: [PATCH] mtd: docg4: fix oob reads This patch does two closely related things: (1) Currently the ecc.read_page() method does not fill the nand->oob_poi buffer with the oob data, but instead reads oob into a local buffer. Fix this by filling the oob_poi buffer instead of a local buffer. The 'oob_required' argument is quietly ignored; the device must always read oob after the page data, and it is presumed that there's no harm in filling oob_poi, even when not explicitly requested. (2) Always read oob from the device in ecc.read_oob(), instead of copying it from a local buffer under some circumstances. Signed-off-by: Mike Dunn Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- drivers/mtd/nand/docg4.c | 33 ++++++--------------------------- 1 file changed, 6 insertions(+), 27 deletions(-) diff --git a/drivers/mtd/nand/docg4.c b/drivers/mtd/nand/docg4.c index 0f2ffd7b6c82..793921e56f8e 100644 --- a/drivers/mtd/nand/docg4.c +++ b/drivers/mtd/nand/docg4.c @@ -378,9 +378,9 @@ static int correct_data(struct mtd_info *mtd, uint8_t *buf, int page) * bit flips(s) are not reported in stats. */ - if (doc->oob_buf[15]) { + if (nand->oob_poi[15]) { int bit, numsetbits = 0; - unsigned long written_flag = doc->oob_buf[15]; + unsigned long written_flag = nand->oob_poi[15]; for_each_set_bit(bit, &written_flag, 8) numsetbits++; if (numsetbits > 4) { /* assume blank */ @@ -428,7 +428,7 @@ static int correct_data(struct mtd_info *mtd, uint8_t *buf, int page) /* if error within oob area preceeding ecc bytes... */ if (errpos[i] > DOCG4_PAGE_SIZE * 8) change_bit(errpos[i] - DOCG4_PAGE_SIZE * 8, - (unsigned long *)doc->oob_buf); + (unsigned long *)nand->oob_poi); else /* error in page data */ change_bit(errpos[i], (unsigned long *)buf); @@ -748,18 +748,12 @@ static int read_page(struct mtd_info *mtd, struct nand_chip *nand, docg4_read_buf(mtd, buf, DOCG4_PAGE_SIZE); /* read the page data */ - /* - * Diskonchips read oob immediately after a page read. Mtd - * infrastructure issues a separate command for reading oob after the - * page is read. So we save the oob bytes in a local buffer and just - * copy it if the next command reads oob from the same page. - */ - + /* this device always reads oob after page data */ /* first 14 oob bytes read from I/O reg */ - docg4_read_buf(mtd, doc->oob_buf, 14); + docg4_read_buf(mtd, nand->oob_poi, 14); /* last 2 read from another reg */ - buf16 = (uint16_t *)(doc->oob_buf + 14); + buf16 = (uint16_t *)(nand->oob_poi + 14); *buf16 = readw(docptr + DOCG4_MYSTERY_REG); write_nop(docptr); @@ -807,21 +801,6 @@ static int docg4_read_oob(struct mtd_info *mtd, struct nand_chip *nand, dev_dbg(doc->dev, "%s: page %x\n", __func__, page); - /* - * Oob bytes are read as part of a normal page read. If the previous - * nand command was a read of the page whose oob is now being read, just - * copy the oob bytes that we saved in a local buffer and avoid a - * separate oob read. - */ - if (doc->last_command.command == NAND_CMD_READ0 && - doc->last_command.page == page) { - memcpy(nand->oob_poi, doc->oob_buf, 16); - return 0; - } - - /* - * Separate read of oob data only. - */ docg4_command(mtd, NAND_CMD_READ0, nand->ecc.size, page); writew(DOC_ECCCONF0_READ_MODE | DOCG4_OOB_SIZE, docptr + DOC_ECCCONF0);