diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c index c2960ac9f39c9e..811775aa8ee800 100644 --- a/drivers/mtd/ubi/io.c +++ b/drivers/mtd/ubi/io.c @@ -482,10 +482,17 @@ static int nor_erase_prepare(struct ubi_device *ubi, int pnum) uint32_t data = 0; struct ubi_vid_hdr vid_hdr; - addr = (loff_t)pnum * ubi->peb_size + ubi->vid_hdr_aloffset; + /* + * It is important to first invalidate the EC header, and then the VID + * header. Otherwise a power cut may lead to valid EC header and + * invalid VID header, in which case UBI will treat this PEB as + * corrupted and will try to preserve it, and print scary warnings (see + * the header comment in scan.c for more information). + */ + addr = (loff_t)pnum * ubi->peb_size; err = ubi->mtd->write(ubi->mtd, addr, 4, &written, (void *)&data); if (!err) { - addr -= ubi->vid_hdr_aloffset; + addr += ubi->vid_hdr_aloffset; err = ubi->mtd->write(ubi->mtd, addr, 4, &written, (void *)&data); if (!err) @@ -494,18 +501,24 @@ static int nor_erase_prepare(struct ubi_device *ubi, int pnum) /* * We failed to write to the media. This was observed with Spansion - * S29GL512N NOR flash. Most probably the eraseblock erasure was - * interrupted at a very inappropriate moment, so it became unwritable. - * In this case we probably anyway have garbage in this PEB. + * S29GL512N NOR flash. Most probably the previously eraseblock erasure + * was interrupted at a very inappropriate moment, so it became + * unwritable. In this case we probably anyway have garbage in this + * PEB. */ err1 = ubi_io_read_vid_hdr(ubi, pnum, &vid_hdr, 0); - if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR) - /* - * The VID header is corrupted, so we can safely erase this - * PEB and not afraid that it will be treated as a valid PEB in - * case of an unclean reboot. - */ - return 0; + if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR) { + struct ubi_ec_hdr ec_hdr; + + err1 = ubi_io_read_ec_hdr(ubi, pnum, &ec_hdr, 0); + if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR) + /* + * Both VID and EC headers are corrupted, so we can + * safely erase this PEB and not afraid that it will be + * treated as a valid PEB in case of an unclean reboot. + */ + return 0; + } /* * The PEB contains a valid VID header, but we cannot invalidate it. diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c index 204345be8e620f..79ca304fc4db61 100644 --- a/drivers/mtd/ubi/scan.c +++ b/drivers/mtd/ubi/scan.c @@ -953,6 +953,10 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, * impossible to distinguish it from a PEB which just * contains garbage because of a power cut during erase * operation. So we just schedule this PEB for erasure. + * + * Besides, in case of NOR flash, we deliberatly + * corrupt both headers because NOR flash erasure is + * slow and can start from the end. */ err = 0; else