From 7e7e4730c178f32a14b781f7c55564d99c4dda3f Mon Sep 17 00:00:00 2001 From: Baruch Siach Date: Wed, 13 May 2015 11:17:37 +0300 Subject: mtd: mxc_nand: limit the size of used oob MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit For 4k pages the i.MX NFC hardware uses no more than 218 bytes for 8bit ECC data. Larger oobsize confuses the logic of copy_spare(). Limit the size of used oob size to avoid that. Reviewed-by: Sascha Hauer Acked-by: Uwe Kleine-König Signed-off-by: Baruch Siach Signed-off-by: Brian Norris --- drivers/mtd/nand/mxc_nand.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) (limited to 'drivers/mtd/nand') diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c index 5bbc1c5062bc..ceeb61cad7d4 100644 --- a/drivers/mtd/nand/mxc_nand.c +++ b/drivers/mtd/nand/mxc_nand.c @@ -189,6 +189,7 @@ struct mxc_nand_host { int clk_act; int irq; int eccsize; + int used_oobsize; int active_cs; struct completion op_completion; @@ -827,7 +828,7 @@ static void copy_spare(struct mtd_info *mtd, bool bfrom) u16 sparebuf_size = host->devtype_data->spare_len; /* size of oob chunk for all but possibly the last one */ - oob_chunk_size = (mtd->oobsize / num_chunks) & ~1; + oob_chunk_size = (host->used_oobsize / num_chunks) & ~1; if (bfrom) { for (i = 0; i < num_chunks - 1; i++) @@ -838,7 +839,7 @@ static void copy_spare(struct mtd_info *mtd, bool bfrom) /* the last chunk */ memcpy32_fromio(d + i * oob_chunk_size, s + i * sparebuf_size, - mtd->oobsize - i * oob_chunk_size); + host->used_oobsize - i * oob_chunk_size); } else { for (i = 0; i < num_chunks - 1; i++) memcpy32_toio(&s[i * sparebuf_size], @@ -848,7 +849,7 @@ static void copy_spare(struct mtd_info *mtd, bool bfrom) /* the last chunk */ memcpy32_toio(&s[oob_chunk_size * sparebuf_size], &d[i * oob_chunk_size], - mtd->oobsize - i * oob_chunk_size); + host->used_oobsize - i * oob_chunk_size); } } @@ -1606,6 +1607,15 @@ static int mxcnd_probe(struct platform_device *pdev) else if (mtd->writesize == 4096) this->ecc.layout = host->devtype_data->ecclayout_4k; + /* + * Experimentation shows that i.MX NFC can only handle up to 218 oob + * bytes. Limit used_oobsize to 218 so as to not confuse copy_spare() + * into copying invalid data to/from the spare IO buffer, as this + * might cause ECC data corruption when doing sub-page write to a + * partially written page. + */ + host->used_oobsize = min(mtd->oobsize, 218U); + if (this->ecc.mode == NAND_ECC_HW) { if (is_imx21_nfc(host) || is_imx27_nfc(host)) this->ecc.strength = 1; -- cgit v1.2.3