Merge tag 'for-linus-3.5-20120601' of git://git.infradead.org/linux-mtd

Pull mtd update from David Woodhouse:
 - More robust parsing especially of xattr data in JFFS2
 - Updates to mxc_nand and gpmi drivers to support new boards and device tree
 - Improve consistency of information about ECC strength in NAND devices
 - Clean up partition handling of plat_nand
 - Support NAND drivers without dedicated access to OOB area
 - BCH hardware ECC support for OMAP
 - Other fixes and cleanups, and a few new device IDs

Fixed trivial conflict in drivers/mtd/nand/gpmi-nand/gpmi-nand.c due to
added include files next to each other.

* tag 'for-linus-3.5-20120601' of git://git.infradead.org/linux-mtd: (75 commits)
  mtd: mxc_nand: move ecc strengh setup before nand_scan_tail
  mtd: block2mtd: fix recursive call of mtd_writev
  mtd: gpmi-nand: define ecc.strength
  mtd: of_parts: fix breakage in Kconfig
  mtd: nand: fix scan_read_raw_oob
  mtd: docg3 fix in-middle of blocks reads
  mtd: cfi_cmdset_0002: Slight cleanup of fixup messages
  mtd: add fixup for S29NS512P NOR flash.
  jffs2: allow to complete xattr integrity check on first GC scan
  jffs2: allow to discriminate between recoverable and non-recoverable errors
  mtd: nand: omap: add support for hardware BCH ecc
  ARM: OMAP3: gpmc: add BCH ecc api and modes
  mtd: nand: check the return code of 'read_oob/read_oob_raw'
  mtd: nand: remove 'sndcmd' parameter of 'read_oob/read_oob_raw'
  mtd: m25p80: Add support for Winbond W25Q80BW
  jffs2: get rid of jffs2_sync_super
  jffs2: remove unnecessary GC pass on sync
  jffs2: remove unnecessary GC pass on umount
  jffs2: remove lock_super
  mtd: gpmi: add gpmi support for mx6q
  ...

1 files changed, 56 insertions, 1 deletions

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index c837507dfb1c..575730744fdb 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -250,6 +250,43 @@ static ssize_t mtd_name_show(struct device *dev,
 }
 static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
 
+static ssize_t mtd_ecc_strength_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct mtd_info *mtd = dev_get_drvdata(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
+}
+static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
+
+static ssize_t mtd_bitflip_threshold_show(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct mtd_info *mtd = dev_get_drvdata(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
+}
+
+static ssize_t mtd_bitflip_threshold_store(struct device *dev,
+					   struct device_attribute *attr,
+					   const char *buf, size_t count)
+{
+	struct mtd_info *mtd = dev_get_drvdata(dev);
+	unsigned int bitflip_threshold;
+	int retval;
+
+	retval = kstrtouint(buf, 0, &bitflip_threshold);
+	if (retval)
+		return retval;
+
+	mtd->bitflip_threshold = bitflip_threshold;
+	return count;
+}
+static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
+		   mtd_bitflip_threshold_show,
+		   mtd_bitflip_threshold_store);
+
 static struct attribute *mtd_attrs[] = {
 	&dev_attr_type.attr,
 	&dev_attr_flags.attr,
@@ -260,6 +297,8 @@ static struct attribute *mtd_attrs[] = {
 	&dev_attr_oobsize.attr,
 	&dev_attr_numeraseregions.attr,
 	&dev_attr_name.attr,
+	&dev_attr_ecc_strength.attr,
+	&dev_attr_bitflip_threshold.attr,
 	NULL,
 };
 
@@ -322,6 +361,10 @@ int add_mtd_device(struct mtd_info *mtd)
 	mtd->index = i;
 	mtd->usecount = 0;
 
+	/* default value if not set by driver */
+	if (mtd->bitflip_threshold == 0)
+		mtd->bitflip_threshold = mtd->ecc_strength;
+
 	if (is_power_of_2(mtd->erasesize))
 		mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
 	else
@@ -757,12 +800,24 @@ EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
 	     u_char *buf)
 {
+	int ret_code;
 	*retlen = 0;
 	if (from < 0 || from > mtd->size || len > mtd->size - from)
 		return -EINVAL;
 	if (!len)
 		return 0;
-	return mtd->_read(mtd, from, len, retlen, buf);
+
+	/*
+	 * In the absence of an error, drivers return a non-negative integer
+	 * representing the maximum number of bitflips that were corrected on
+	 * any one ecc region (if applicable; zero otherwise).
+	 */
+	ret_code = mtd->_read(mtd, from, len, retlen, buf);
+	if (unlikely(ret_code < 0))
+		return ret_code;
+	if (mtd->ecc_strength == 0)
+		return 0;	/* device lacks ecc */
+	return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
 }
 EXPORT_SYMBOL_GPL(mtd_read);