1 files changed, 22 insertions, 32 deletions

diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index bf79def40126..d36134925d31 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -495,10 +495,12 @@ out:
  */
 static int nor_erase_prepare(struct ubi_device *ubi, int pnum)
 {
-        int err, err1;
+        int err;
         size_t written;
         loff_t addr;
         uint32_t data = 0;
+        struct ubi_ec_hdr ec_hdr;
+
         /*
          * Note, we cannot generally define VID header buffers on stack,
          * because of the way we deal with these buffers (see the header
@@ -509,50 +511,38 @@ static int nor_erase_prepare(struct ubi_device *ubi, int pnum)
         struct ubi_vid_hdr vid_hdr;
 
         /*
+         * If VID or EC is valid, we have to corrupt them before erasing.
          * 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.
          */
         addr = (loff_t)pnum * ubi->peb_size;
-        err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);
-        if (!err) {
-                addr += ubi->vid_hdr_aloffset;
+        err = ubi_io_read_ec_hdr(ubi, pnum, &ec_hdr, 0);
+        if (err != UBI_IO_BAD_HDR_EBADMSG && err != UBI_IO_BAD_HDR &&
+            err != UBI_IO_FF){
                 err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);
-                if (!err)
-                        return 0;
+                if(err)
+                        goto error;
         }
 
-        /*
-         * We failed to write to the media. This was observed with Spansion
-         * 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 ||
-            err1 == UBI_IO_FF) {
-                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 ||
-                    err1 == UBI_IO_FF)
-                        /*
-                         * 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;
+        err = ubi_io_read_vid_hdr(ubi, pnum, &vid_hdr, 0);
+        if (err != UBI_IO_BAD_HDR_EBADMSG && err != UBI_IO_BAD_HDR &&
+            err != UBI_IO_FF){
+                addr += ubi->vid_hdr_aloffset;
+                err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);
+                if (err)
+                        goto error;
         }
+        return 0;
 
+error:
         /*
-         * The PEB contains a valid VID header, but we cannot invalidate it.
-         * Supposedly the flash media or the driver is screwed up, so return an
-         * error.
+         * The PEB contains a valid VID or EC header, but we cannot invalidate
+         * it. Supposedly the flash media or the driver is screwed up, so
+         * return an error.
          */
-        ubi_err("cannot invalidate PEB %d, write returned %d read returned %d",
-                pnum, err, err1);
+        ubi_err("cannot invalidate PEB %d, write returned %d", pnum, err);
         ubi_dump_flash(ubi, pnum, 0, ubi->peb_size);
         return -EIO;
 }