mtd: nand: remove NAND_BBT_SCANEMPTY

NAND_BBT_SCANEMPTY is a strange, badly-supported option with omap as its
single remaining user.

NAND_BBT_SCANEMPTY was likely used by accident in omap2[1]. And anyway,
omap2 doesn't scan the chip for bad blocks (courtesy of
NAND_SKIP_BBTSCAN), and so its use of this option is irrelevant.

This patch drops the NAND_BBT_SCANEMPTY option.

[1] http://lists.infradead.org/pipermail/linux-mtd/2012-July/042902.html

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Ivan Djelic <ivan.djelic@parrot.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Huang Shijie <b32955@freescale.com>

5 files changed, 6 insertions, 34 deletions

diff --git a/Documentation/DocBook/mtdnand.tmpl b/Documentation/DocBook/mtdnand.tmpl
index fe122d6e686f..a248f42a121e 100644
--- a/Documentation/DocBook/mtdnand.tmpl
+++ b/Documentation/DocBook/mtdnand.tmpl
@@ -1224,8 +1224,6 @@ in this page</entry>
 #define NAND_BBT_CREATE         0x00000200
 /* Search good / bad pattern through all pages of a block */
 #define NAND_BBT_SCANALLPAGES   0x00000400
-/* Scan block empty during good / bad block scan */
-#define NAND_BBT_SCANEMPTY      0x00000800
 /* Write bbt if neccecary */
 #define NAND_BBT_WRITE          0x00001000
 /* Read and write back block contents when writing bbt */
diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c
index ae3fb58591cf..bc06196d5739 100644
--- a/drivers/mtd/nand/nand_bbt.c
+++ b/drivers/mtd/nand/nand_bbt.c
@@ -110,33 +110,17 @@ static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td)
  * @td: search pattern descriptor
  *
  * Check for a pattern at the given place. Used to search bad block tables and
- * good / bad block identifiers. If the SCAN_EMPTY option is set then check, if
- * all bytes except the pattern area contain 0xff.
+ * good / bad block identifiers.
  */
 static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
 {
-        int end = 0;
-        uint8_t *p = buf;
-
         if (td->options & NAND_BBT_NO_OOB)
                 return check_pattern_no_oob(buf, td);
 
-        end = paglen + td->offs;
-        if (td->options & NAND_BBT_SCANEMPTY)
-                if (memchr_inv(p, 0xff, end))
-                        return -1;
-        p += end;
-
         /* Compare the pattern */
-        if (memcmp(p, td->pattern, td->len))
+        if (memcmp(buf + paglen + td->offs, td->pattern, td->len))
                 return -1;
 
-        if (td->options & NAND_BBT_SCANEMPTY) {
-                p += td->len;
-                end += td->len;
-                if (memchr_inv(p, 0xff, len - end))
-                        return -1;
-        }
         return 0;
 }
 
@@ -507,15 +491,9 @@ static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
         else
                 numpages = 1;
 
-        if (!(bd->options & NAND_BBT_SCANEMPTY)) {
-                /* We need only read few bytes from the OOB area */
-                scanlen = 0;
-                readlen = bd->len;
-        } else {
-                /* Full page content should be read */
-                scanlen = mtd->writesize + mtd->oobsize;
-                readlen = numpages * mtd->writesize;
-        }
+        /* We need only read few bytes from the OOB area */
+        scanlen = 0;
+        readlen = bd->len;
 
         if (chip == -1) {
                 numblocks = mtd->size >> this->bbt_erase_shift;
@@ -882,7 +860,6 @@ static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *b
 {
         struct nand_chip *this = mtd->priv;
 
-        bd->options &= ~NAND_BBT_SCANEMPTY;
         return create_bbt(mtd, this->buffers->databuf, bd, -1);
 }
 
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 81b80af55872..35f4490c010d 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -154,7 +154,7 @@ static struct nand_ecclayout omap_oobinfo;
  */
 static uint8_t scan_ff_pattern[] = { 0xff };
 static struct nand_bbt_descr bb_descrip_flashbased = {
-        .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
+        .options = NAND_BBT_SCANALLPAGES,
         .offs = 0,
         .len = 1,
         .pattern = scan_ff_pattern,
diff --git a/drivers/mtd/onenand/onenand_bbt.c b/drivers/mtd/onenand/onenand_bbt.c
index 66fe3b7e7851..08d0085f3e93 100644
--- a/drivers/mtd/onenand/onenand_bbt.c
+++ b/drivers/mtd/onenand/onenand_bbt.c
@@ -133,7 +133,6 @@ static inline int onenand_memory_bbt (struct mtd_info *mtd, struct nand_bbt_desc
 {
         struct onenand_chip *this = mtd->priv;
 
-        bd->options &= ~NAND_BBT_SCANEMPTY;
         return create_bbt(mtd, this->page_buf, bd, -1);
 }
 
diff --git a/include/linux/mtd/bbm.h b/include/linux/mtd/bbm.h
index 211ff67e8b0d..95fc482cef36 100644
--- a/include/linux/mtd/bbm.h
+++ b/include/linux/mtd/bbm.h
@@ -93,8 +93,6 @@ struct nand_bbt_descr {
 #define NAND_BBT_CREATE_EMPTY   0x00000400
 /* Search good / bad pattern through all pages of a block */
 #define NAND_BBT_SCANALLPAGES   0x00000800
-/* Scan block empty during good / bad block scan */
-#define NAND_BBT_SCANEMPTY      0x00001000
 /* Write bbt if neccecary */
 #define NAND_BBT_WRITE          0x00002000
 /* Read and write back block contents when writing bbt */