From 67e5a28b35254bbbcd5bfce61ef646709e059bbf Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Mon, 14 Apr 2008 09:39:39 +0300 Subject: [MTD] [OneNAND] Allow for controller errors when reading A power loss while writing can result in a page becoming unreadable. When the device is mounted again, reading that page gives controller errors. Upper level software like JFFS2 treat -EIO as fatal, refusing to mount at all. That means it is necessary to treat the error as an ECC error to allow recovery. Note that typically in this case, the eraseblock can still be erased and rewritten i.e. it has not become a bad block. Signed-off-by: Adrian Hunter Signed-off-by: David Woodhouse --- drivers/mtd/onenand/onenand_base.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'drivers/mtd/onenand') diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c index 56255c85d97b..5d7965f7e9ce 100644 --- a/drivers/mtd/onenand/onenand_base.c +++ b/drivers/mtd/onenand/onenand_base.c @@ -329,6 +329,21 @@ static int onenand_wait(struct mtd_info *mtd, int state) printk(KERN_ERR "onenand_wait: controller error = 0x%04x\n", ctrl); if (ctrl & ONENAND_CTRL_LOCK) printk(KERN_ERR "onenand_wait: it's locked error.\n"); + if (state == FL_READING) { + /* + * A power loss while writing can result in a page + * becoming unreadable. When the device is mounted + * again, reading that page gives controller errors. + * Upper level software like JFFS2 treat -EIO as fatal, + * refusing to mount at all. That means it is necessary + * to treat the error as an ECC error to allow recovery. + * Note that typically in this case, the eraseblock can + * still be erased and rewritten i.e. it has not become + * a bad block. + */ + mtd->ecc_stats.failed++; + return -EBADMSG; + } return -EIO; } -- cgit v1.2.3