UBI: add a comment
It is not clear why we schedule PEB for scrubbing in case of
-EBADMSG. Elaborate.
Requested-by: Kyungmin Park <kmpark@infradead.org>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c
index 3c4d68f..42a7815 100644
--- a/drivers/mtd/ubi/vtbl.c
+++ b/drivers/mtd/ubi/vtbl.c
@@ -385,7 +385,16 @@
err = ubi_io_read_data(ubi, leb[seb->lnum], seb->pnum, 0,
ubi->vtbl_size);
if (err == UBI_IO_BITFLIPS || err == -EBADMSG)
- /* Scrub the PEB later */
+ /*
+ * Scrub the PEB later. Note, -EBADMSG indicates an
+ * uncorrectable ECC error, but we have our own CRC and
+ * the data will be checked later. If the data is OK,
+ * the PEB will be scrubbed (because we set
+ * seb->scrub). If the data is not OK, the contents of
+ * the PEB will be recovered from the second copy, and
+ * seb->scrub will be cleared in
+ * 'ubi_scan_add_used()'.
+ */
seb->scrub = 1;
else if (err)
goto out_free;