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authorAdrian Hunter <Adrian.Hunter@nokia.com>2009-07-24 12:16:04 -0400
committerArtem Bityutskiy <Artem.Bityutskiy@nokia.com>2009-07-24 13:08:52 -0400
commit32bc4820287a1a03982979515949e8ea56eac641 (patch)
tree2d7968ed99b21f84e41adfda4709dbf4acf585e7 /drivers/mtd/ubi
parent7194e6f9c083e87171ddfc8b746f05e007f58132 (diff)
UBI: compatible fallback in absense of sequence numbers
Fall back onto thinking everything's OK if either of the sequence numbers we are asked to compare is zero, which is what was used before sequence numbers were introduced. [ Artem: modified the patch to be applicable to upstream UBI, added big comment ] Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com> Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Diffstat (limited to 'drivers/mtd/ubi')
-rw-r--r--drivers/mtd/ubi/scan.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c
index a423131b6171..b847745394b4 100644
--- a/drivers/mtd/ubi/scan.c
+++ b/drivers/mtd/ubi/scan.c
@@ -781,11 +781,22 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
781 return -EINVAL; 781 return -EINVAL;
782 } 782 }
783 783
784 /*
785 * Make sure that all PEBs have the same image sequence number.
786 * This allows us to detect situations when users flash UBI
787 * images incorrectly, so that the flash has the new UBI image
788 * and leftovers from the old one. This feature was added
789 * relatively recently, and the sequence number was always
790 * zero, because old UBI implementations always set it to zero.
791 * For this reasons, we do not panic if some PEBs have zero
792 * sequence number, while other PEBs have non-zero sequence
793 * number.
794 */
784 image_seq = be32_to_cpu(ech->image_seq); 795 image_seq = be32_to_cpu(ech->image_seq);
785 if (!si->image_seq_set) { 796 if (!si->image_seq_set) {
786 ubi->image_seq = image_seq; 797 ubi->image_seq = image_seq;
787 si->image_seq_set = 1; 798 si->image_seq_set = 1;
788 } else if (ubi->image_seq != image_seq) { 799 } else if (ubi->image_seq && ubi->image_seq != image_seq) {
789 ubi_err("bad image sequence number %d in PEB %d, " 800 ubi_err("bad image sequence number %d in PEB %d, "
790 "expected %d", image_seq, pnum, ubi->image_seq); 801 "expected %d", image_seq, pnum, ubi->image_seq);
791 ubi_dbg_dump_ec_hdr(ech); 802 ubi_dbg_dump_ec_hdr(ech);