diff options
| -rw-r--r-- | drivers/mtd/ubi/build.c | 5 | ||||
| -rw-r--r-- | drivers/mtd/ubi/io.c | 58 | ||||
| -rw-r--r-- | drivers/mtd/ubi/ubi.h | 4 |
3 files changed, 64 insertions, 3 deletions
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c index db0b9cb..e1f7d0a 100644 --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -657,6 +657,11 @@ static int io_init(struct ubi_device *ubi) if (ubi->mtd->block_isbad && ubi->mtd->block_markbad) ubi->bad_allowed = 1; + if (ubi->mtd->type == MTD_NORFLASH) { + ubi_assert(ubi->mtd->writesize == 1); + ubi->nor_flash = 1; + } + ubi->min_io_size = ubi->mtd->writesize; ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft; diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c index 1ea1421..c3bd2e3 100644 --- a/drivers/mtd/ubi/io.c +++ b/drivers/mtd/ubi/io.c @@ -266,8 +266,8 @@ int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset, addr = (loff_t)pnum * ubi->peb_size + offset; err = ubi->mtd->write(ubi->mtd, addr, len, &written, buf); if (err) { - ubi_err("error %d while writing %d bytes to PEB %d:%d, written" - " %zd bytes", err, len, pnum, offset, written); + ubi_err("error %d while writing %d bytes to PEB %d:%d, written " + "%zd bytes", err, len, pnum, offset, written); ubi_dbg_dump_stack(); } else ubi_assert(written == len); @@ -454,6 +454,54 @@ out: } /** + * nor_erase_prepare - prepare a NOR flash PEB for erasure. + * @ubi: UBI device description object + * @pnum: physical eraseblock number to prepare + * + * NOR flash, or at least some of them, have peculiar embedded PEB erasure + * algorithm: the PEB is first filled with zeroes, then it is erased. And + * filling with zeroes starts from the end of the PEB. This was observed with + * Spansion S29GL512N NOR flash. + * + * This means that in case of a power cut we may end up with intact data at the + * beginning of the PEB, and all zeroes at the end of PEB. In other words, the + * EC and VID headers are OK, but a large chunk of data at the end of PEB is + * zeroed. This makes UBI mistakenly treat this PEB as used and associate it + * with an LEB, which leads to subsequent failures (e.g., UBIFS fails). + * + * This function is called before erasing NOR PEBs and it zeroes out EC and VID + * magic numbers in order to invalidate them and prevent the failures. Returns + * zero in case of success and a negative error code in case of failure. + */ +static int nor_erase_prepare(struct ubi_device *ubi, int pnum) +{ + int err; + size_t written; + loff_t addr; + uint32_t data = 0; + + addr = (loff_t)pnum * ubi->peb_size; + err = ubi->mtd->write(ubi->mtd, addr, 4, &written, &data); + if (err) { + ubi_err("error %d while writing 4 bytes to PEB %d:0, written " + "%zd bytes", err, pnum, 0, written); + ubi_dbg_dump_stack(); + return err; + } + + addr += ubi->vid_hdr_aloffset; + err = ubi->mtd->write(ubi->mtd, addr, 4, &written, &data); + if (err) { + ubi_err("error %d while writing 4 bytes to PEB %d:%d, written " + "%zd bytes", err, pnum, ubi->vid_hdr_aloffset, written); + ubi_dbg_dump_stack(); + return err; + } + + return 0; +} + +/** * ubi_io_sync_erase - synchronously erase a physical eraseblock. * @ubi: UBI device description object * @pnum: physical eraseblock number to erase @@ -484,6 +532,12 @@ int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture) return -EROFS; } + if (ubi->nor_flash) { + err = nor_erase_prepare(ubi, pnum); + if (err) + return err; + } + if (torture) { ret = torture_peb(ubi, pnum); if (ret < 0) diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h index 64604e8..6a5fe96 100644 --- a/drivers/mtd/ubi/ubi.h +++ b/drivers/mtd/ubi/ubi.h @@ -373,6 +373,7 @@ struct ubi_wl_entry; * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or * not + * @nor_flash: non-zero if working on top of NOR flash * @mtd: MTD device descriptor * * @peb_buf1: a buffer of PEB size used for different purposes @@ -454,7 +455,8 @@ struct ubi_device { int vid_hdr_offset; int vid_hdr_aloffset; int vid_hdr_shift; - int bad_allowed; + unsigned int bad_allowed:1; + unsigned int nor_flash:1; struct mtd_info *mtd; void *peb_buf1; |