Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 750 insertions, 0 deletions

diff --git a/drivers/mtd/tests/oobtest.c b/drivers/mtd/tests/oobtest.c
new file mode 100644
index 000000000..766b2c385
--- /dev/null
+++ b/drivers/mtd/tests/oobtest.c
@@ -0,0 +1,750 @@
+/*
+ * Copyright (C) 2006-2008 Nokia Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; see the file COPYING. If not, write to the Free Software
+ * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Test OOB read and write on MTD device.
+ *
+ * Author: Adrian Hunter <ext-adrian.hunter@nokia.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <asm/div64.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/err.h>
+#include <linux/mtd/mtd.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/random.h>
+
+#include "mtd_test.h"
+
+static int dev = -EINVAL;
+static int bitflip_limit;
+module_param(dev, int, S_IRUGO);
+MODULE_PARM_DESC(dev, "MTD device number to use");
+module_param(bitflip_limit, int, S_IRUGO);
+MODULE_PARM_DESC(bitflip_limit, "Max. allowed bitflips per page");
+
+static struct mtd_info *mtd;
+static unsigned char *readbuf;
+static unsigned char *writebuf;
+static unsigned char *bbt;
+
+static int ebcnt;
+static int pgcnt;
+static int errcnt;
+static int use_offset;
+static int use_len;
+static int use_len_max;
+static int vary_offset;
+static struct rnd_state rnd_state;
+
+static void do_vary_offset(void)
+{
+	use_len -= 1;
+	if (use_len < 1) {
+		use_offset += 1;
+		if (use_offset >= use_len_max)
+			use_offset = 0;
+		use_len = use_len_max - use_offset;
+	}
+}
+
+static int write_eraseblock(int ebnum)
+{
+	int i;
+	struct mtd_oob_ops ops;
+	int err = 0;
+	loff_t addr = (loff_t)ebnum * mtd->erasesize;
+
+	prandom_bytes_state(&rnd_state, writebuf, use_len_max * pgcnt);
+	for (i = 0; i < pgcnt; ++i, addr += mtd->writesize) {
+		ops.mode      = MTD_OPS_AUTO_OOB;
+		ops.len       = 0;
+		ops.retlen    = 0;
+		ops.ooblen    = use_len;
+		ops.oobretlen = 0;
+		ops.ooboffs   = use_offset;
+		ops.datbuf    = NULL;
+		ops.oobbuf    = writebuf + (use_len_max * i) + use_offset;
+		err = mtd_write_oob(mtd, addr, &ops);
+		if (err || ops.oobretlen != use_len) {
+			pr_err("error: writeoob failed at %#llx\n",
+			       (long long)addr);
+			pr_err("error: use_len %d, use_offset %d\n",
+			       use_len, use_offset);
+			errcnt += 1;
+			return err ? err : -1;
+		}
+		if (vary_offset)
+			do_vary_offset();
+	}
+
+	return err;
+}
+
+static int write_whole_device(void)
+{
+	int err;
+	unsigned int i;
+
+	pr_info("writing OOBs of whole device\n");
+	for (i = 0; i < ebcnt; ++i) {
+		if (bbt[i])
+			continue;
+		err = write_eraseblock(i);
+		if (err)
+			return err;
+		if (i % 256 == 0)
+			pr_info("written up to eraseblock %u\n", i);
+
+		err = mtdtest_relax();
+		if (err)
+			return err;
+	}
+	pr_info("written %u eraseblocks\n", i);
+	return 0;
+}
+
+/*
+ * Display the address, offset and data bytes at comparison failure.
+ * Return number of bitflips encountered.
+ */
+static size_t memcmpshowoffset(loff_t addr, loff_t offset, const void *cs,
+			       const void *ct, size_t count)
+{
+	const unsigned char *su1, *su2;
+	int res;
+	size_t i = 0;
+	size_t bitflips = 0;
+
+	for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--, i++) {
+		res = *su1 ^ *su2;
+		if (res) {
+			pr_info("error @addr[0x%lx:0x%lx] 0x%x -> 0x%x diff 0x%x\n",
+				(unsigned long)addr, (unsigned long)offset + i,
+				*su1, *su2, res);
+			bitflips += hweight8(res);
+		}
+	}
+
+	return bitflips;
+}
+
+#define memcmpshow(addr, cs, ct, count) memcmpshowoffset((addr), 0, (cs), (ct),\
+							 (count))
+
+/*
+ * Compare with 0xff and show the address, offset and data bytes at
+ * comparison failure. Return number of bitflips encountered.
+ */
+static size_t memffshow(loff_t addr, loff_t offset, const void *cs,
+			size_t count)
+{
+	const unsigned char *su1;
+	int res;
+	size_t i = 0;
+	size_t bitflips = 0;
+
+	for (su1 = cs; 0 < count; ++su1, count--, i++) {
+		res = *su1 ^ 0xff;
+		if (res) {
+			pr_info("error @addr[0x%lx:0x%lx] 0x%x -> 0xff diff 0x%x\n",
+				(unsigned long)addr, (unsigned long)offset + i,
+				*su1, res);
+			bitflips += hweight8(res);
+		}
+	}
+
+	return bitflips;
+}
+
+static int verify_eraseblock(int ebnum)
+{
+	int i;
+	struct mtd_oob_ops ops;
+	int err = 0;
+	loff_t addr = (loff_t)ebnum * mtd->erasesize;
+	size_t bitflips;
+
+	prandom_bytes_state(&rnd_state, writebuf, use_len_max * pgcnt);
+	for (i = 0; i < pgcnt; ++i, addr += mtd->writesize) {
+		ops.mode      = MTD_OPS_AUTO_OOB;
+		ops.len       = 0;
+		ops.retlen    = 0;
+		ops.ooblen    = use_len;
+		ops.oobretlen = 0;
+		ops.ooboffs   = use_offset;
+		ops.datbuf    = NULL;
+		ops.oobbuf    = readbuf;
+		err = mtd_read_oob(mtd, addr, &ops);
+		if (mtd_is_bitflip(err))
+			err = 0;
+
+		if (err || ops.oobretlen != use_len) {
+			pr_err("error: readoob failed at %#llx\n",
+			       (long long)addr);
+			errcnt += 1;
+			return err ? err : -1;
+		}
+
+		bitflips = memcmpshow(addr, readbuf,
+				      writebuf + (use_len_max * i) + use_offset,
+				      use_len);
+		if (bitflips > bitflip_limit) {
+			pr_err("error: verify failed at %#llx\n",
+			       (long long)addr);
+			errcnt += 1;
+			if (errcnt > 1000) {
+				pr_err("error: too many errors\n");
+				return -1;
+			}
+		} else if (bitflips) {
+			pr_info("ignoring error as within bitflip_limit\n");
+		}
+
+		if (use_offset != 0 || use_len < mtd->oobavail) {
+			int k;
+
+			ops.mode      = MTD_OPS_AUTO_OOB;
+			ops.len       = 0;
+			ops.retlen    = 0;
+			ops.ooblen    = mtd->oobavail;
+			ops.oobretlen = 0;
+			ops.ooboffs   = 0;
+			ops.datbuf    = NULL;
+			ops.oobbuf    = readbuf;
+			err = mtd_read_oob(mtd, addr, &ops);
+			if (mtd_is_bitflip(err))
+				err = 0;
+
+			if (err || ops.oobretlen != mtd->oobavail) {
+				pr_err("error: readoob failed at %#llx\n",
+						(long long)addr);
+				errcnt += 1;
+				return err ? err : -1;
+			}
+			bitflips = memcmpshowoffset(addr, use_offset,
+						    readbuf + use_offset,
+						    writebuf + (use_len_max * i) + use_offset,
+						    use_len);
+
+			/* verify pre-offset area for 0xff */
+			bitflips += memffshow(addr, 0, readbuf, use_offset);
+
+			/* verify post-(use_offset + use_len) area for 0xff */
+			k = use_offset + use_len;
+			bitflips += memffshow(addr, k, readbuf + k,
+					      mtd->oobavail - k);
+
+			if (bitflips > bitflip_limit) {
+				pr_err("error: verify failed at %#llx\n",
+						(long long)addr);
+				errcnt += 1;
+				if (errcnt > 1000) {
+					pr_err("error: too many errors\n");
+					return -1;
+				}
+			} else if (bitflips) {
+				pr_info("ignoring errors as within bitflip limit\n");
+			}
+		}
+		if (vary_offset)
+			do_vary_offset();
+	}
+	return err;
+}
+
+static int verify_eraseblock_in_one_go(int ebnum)
+{
+	struct mtd_oob_ops ops;
+	int err = 0;
+	loff_t addr = (loff_t)ebnum * mtd->erasesize;
+	size_t len = mtd->oobavail * pgcnt;
+	size_t oobavail = mtd->oobavail;
+	size_t bitflips;
+	int i;
+
+	prandom_bytes_state(&rnd_state, writebuf, len);
+	ops.mode      = MTD_OPS_AUTO_OOB;
+	ops.len       = 0;
+	ops.retlen    = 0;
+	ops.ooblen    = len;
+	ops.oobretlen = 0;
+	ops.ooboffs   = 0;
+	ops.datbuf    = NULL;
+	ops.oobbuf    = readbuf;
+
+	/* read entire block's OOB at one go */
+	err = mtd_read_oob(mtd, addr, &ops);
+	if (mtd_is_bitflip(err))
+		err = 0;
+
+	if (err || ops.oobretlen != len) {
+		pr_err("error: readoob failed at %#llx\n",
+		       (long long)addr);
+		errcnt += 1;
+		return err ? err : -1;
+	}
+
+	/* verify one page OOB at a time for bitflip per page limit check */
+	for (i = 0; i < pgcnt; ++i, addr += mtd->writesize) {
+		bitflips = memcmpshow(addr, readbuf + (i * oobavail),
+				      writebuf + (i * oobavail), oobavail);
+		if (bitflips > bitflip_limit) {
+			pr_err("error: verify failed at %#llx\n",
+			       (long long)addr);
+			errcnt += 1;
+			if (errcnt > 1000) {
+				pr_err("error: too many errors\n");
+				return -1;
+			}
+		} else if (bitflips) {
+			pr_info("ignoring error as within bitflip_limit\n");
+		}
+	}
+
+	return err;
+}
+
+static int verify_all_eraseblocks(void)
+{
+	int err;
+	unsigned int i;
+
+	pr_info("verifying all eraseblocks\n");
+	for (i = 0; i < ebcnt; ++i) {
+		if (bbt[i])
+			continue;
+		err = verify_eraseblock(i);
+		if (err)
+			return err;
+		if (i % 256 == 0)
+			pr_info("verified up to eraseblock %u\n", i);
+
+		err = mtdtest_relax();
+		if (err)
+			return err;
+	}
+	pr_info("verified %u eraseblocks\n", i);
+	return 0;
+}
+
+static int __init mtd_oobtest_init(void)
+{
+	int err = 0;
+	unsigned int i;
+	uint64_t tmp;
+	struct mtd_oob_ops ops;
+	loff_t addr = 0, addr0;
+
+	printk(KERN_INFO "\n");
+	printk(KERN_INFO "=================================================\n");
+
+	if (dev < 0) {
+		pr_info("Please specify a valid mtd-device via module parameter\n");
+		pr_crit("CAREFUL: This test wipes all data on the specified MTD device!\n");
+		return -EINVAL;
+	}
+
+	pr_info("MTD device: %d\n", dev);
+
+	mtd = get_mtd_device(NULL, dev);
+	if (IS_ERR(mtd)) {
+		err = PTR_ERR(mtd);
+		pr_err("error: cannot get MTD device\n");
+		return err;
+	}
+
+	if (!mtd_type_is_nand(mtd)) {
+		pr_info("this test requires NAND flash\n");
+		goto out;
+	}
+
+	tmp = mtd->size;
+	do_div(tmp, mtd->erasesize);
+	ebcnt = tmp;
+	pgcnt = mtd->erasesize / mtd->writesize;
+
+	pr_info("MTD device size %llu, eraseblock size %u, "
+	       "page size %u, count of eraseblocks %u, pages per "
+	       "eraseblock %u, OOB size %u\n",
+	       (unsigned long long)mtd->size, mtd->erasesize,
+	       mtd->writesize, ebcnt, pgcnt, mtd->oobsize);
+
+	err = -ENOMEM;
+	readbuf = kmalloc(mtd->erasesize, GFP_KERNEL);
+	if (!readbuf)
+		goto out;
+	writebuf = kmalloc(mtd->erasesize, GFP_KERNEL);
+	if (!writebuf)
+		goto out;
+	bbt = kzalloc(ebcnt, GFP_KERNEL);
+	if (!bbt)
+		goto out;
+
+	err = mtdtest_scan_for_bad_eraseblocks(mtd, bbt, 0, ebcnt);
+	if (err)
+		goto out;
+
+	use_offset = 0;
+	use_len = mtd->oobavail;
+	use_len_max = mtd->oobavail;
+	vary_offset = 0;
+
+	/* First test: write all OOB, read it back and verify */
+	pr_info("test 1 of 5\n");
+
+	err = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
+	if (err)
+		goto out;
+
+	prandom_seed_state(&rnd_state, 1);
+	err = write_whole_device();
+	if (err)
+		goto out;
+
+	prandom_seed_state(&rnd_state, 1);
+	err = verify_all_eraseblocks();
+	if (err)
+		goto out;
+
+	/*
+	 * Second test: write all OOB, a block at a time, read it back and
+	 * verify.
+	 */
+	pr_info("test 2 of 5\n");
+
+	err = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
+	if (err)
+		goto out;
+
+	prandom_seed_state(&rnd_state, 3);
+	err = write_whole_device();
+	if (err)
+		goto out;
+
+	/* Check all eraseblocks */
+	prandom_seed_state(&rnd_state, 3);
+	pr_info("verifying all eraseblocks\n");
+	for (i = 0; i < ebcnt; ++i) {
+		if (bbt[i])
+			continue;
+		err = verify_eraseblock_in_one_go(i);
+		if (err)
+			goto out;
+		if (i % 256 == 0)
+			pr_info("verified up to eraseblock %u\n", i);
+
+		err = mtdtest_relax();
+		if (err)
+			goto out;
+	}
+	pr_info("verified %u eraseblocks\n", i);
+
+	/*
+	 * Third test: write OOB at varying offsets and lengths, read it back
+	 * and verify.
+	 */
+	pr_info("test 3 of 5\n");
+
+	err = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
+	if (err)
+		goto out;
+
+	/* Write all eraseblocks */
+	use_offset = 0;
+	use_len = mtd->oobavail;
+	use_len_max = mtd->oobavail;
+	vary_offset = 1;
+	prandom_seed_state(&rnd_state, 5);
+
+	err = write_whole_device();
+	if (err)
+		goto out;
+
+	/* Check all eraseblocks */
+	use_offset = 0;
+	use_len = mtd->oobavail;
+	use_len_max = mtd->oobavail;
+	vary_offset = 1;
+	prandom_seed_state(&rnd_state, 5);
+	err = verify_all_eraseblocks();
+	if (err)
+		goto out;
+
+	use_offset = 0;
+	use_len = mtd->oobavail;
+	use_len_max = mtd->oobavail;
+	vary_offset = 0;
+
+	/* Fourth test: try to write off end of device */
+	pr_info("test 4 of 5\n");
+
+	err = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
+	if (err)
+		goto out;
+
+	addr0 = 0;
+	for (i = 0; i < ebcnt && bbt[i]; ++i)
+		addr0 += mtd->erasesize;
+
+	/* Attempt to write off end of OOB */
+	ops.mode      = MTD_OPS_AUTO_OOB;
+	ops.len       = 0;
+	ops.retlen    = 0;
+	ops.ooblen    = 1;
+	ops.oobretlen = 0;
+	ops.ooboffs   = mtd->oobavail;
+	ops.datbuf    = NULL;
+	ops.oobbuf    = writebuf;
+	pr_info("attempting to start write past end of OOB\n");
+	pr_info("an error is expected...\n");
+	err = mtd_write_oob(mtd, addr0, &ops);
+	if (err) {
+		pr_info("error occurred as expected\n");
+		err = 0;
+	} else {
+		pr_err("error: can write past end of OOB\n");
+		errcnt += 1;
+	}
+
+	/* Attempt to read off end of OOB */
+	ops.mode      = MTD_OPS_AUTO_OOB;
+	ops.len       = 0;
+	ops.retlen    = 0;
+	ops.ooblen    = 1;
+	ops.oobretlen = 0;
+	ops.ooboffs   = mtd->oobavail;
+	ops.datbuf    = NULL;
+	ops.oobbuf    = readbuf;
+	pr_info("attempting to start read past end of OOB\n");
+	pr_info("an error is expected...\n");
+	err = mtd_read_oob(mtd, addr0, &ops);
+	if (mtd_is_bitflip(err))
+		err = 0;
+
+	if (err) {
+		pr_info("error occurred as expected\n");
+		err = 0;
+	} else {
+		pr_err("error: can read past end of OOB\n");
+		errcnt += 1;
+	}
+
+	if (bbt[ebcnt - 1])
+		pr_info("skipping end of device tests because last "
+		       "block is bad\n");
+	else {
+		/* Attempt to write off end of device */
+		ops.mode      = MTD_OPS_AUTO_OOB;
+		ops.len       = 0;
+		ops.retlen    = 0;
+		ops.ooblen    = mtd->oobavail + 1;
+		ops.oobretlen = 0;
+		ops.ooboffs   = 0;
+		ops.datbuf    = NULL;
+		ops.oobbuf    = writebuf;
+		pr_info("attempting to write past end of device\n");
+		pr_info("an error is expected...\n");
+		err = mtd_write_oob(mtd, mtd->size - mtd->writesize, &ops);
+		if (err) {
+			pr_info("error occurred as expected\n");
+			err = 0;
+		} else {
+			pr_err("error: wrote past end of device\n");
+			errcnt += 1;
+		}
+
+		/* Attempt to read off end of device */
+		ops.mode      = MTD_OPS_AUTO_OOB;
+		ops.len       = 0;
+		ops.retlen    = 0;
+		ops.ooblen    = mtd->oobavail + 1;
+		ops.oobretlen = 0;
+		ops.ooboffs   = 0;
+		ops.datbuf    = NULL;
+		ops.oobbuf    = readbuf;
+		pr_info("attempting to read past end of device\n");
+		pr_info("an error is expected...\n");
+		err = mtd_read_oob(mtd, mtd->size - mtd->writesize, &ops);
+		if (mtd_is_bitflip(err))
+			err = 0;
+
+		if (err) {
+			pr_info("error occurred as expected\n");
+			err = 0;
+		} else {
+			pr_err("error: read past end of device\n");
+			errcnt += 1;
+		}
+
+		err = mtdtest_erase_eraseblock(mtd, ebcnt - 1);
+		if (err)
+			goto out;
+
+		/* Attempt to write off end of device */
+		ops.mode      = MTD_OPS_AUTO_OOB;
+		ops.len       = 0;
+		ops.retlen    = 0;
+		ops.ooblen    = mtd->oobavail;
+		ops.oobretlen = 0;
+		ops.ooboffs   = 1;
+		ops.datbuf    = NULL;
+		ops.oobbuf    = writebuf;
+		pr_info("attempting to write past end of device\n");
+		pr_info("an error is expected...\n");
+		err = mtd_write_oob(mtd, mtd->size - mtd->writesize, &ops);
+		if (err) {
+			pr_info("error occurred as expected\n");
+			err = 0;
+		} else {
+			pr_err("error: wrote past end of device\n");
+			errcnt += 1;
+		}
+
+		/* Attempt to read off end of device */
+		ops.mode      = MTD_OPS_AUTO_OOB;
+		ops.len       = 0;
+		ops.retlen    = 0;
+		ops.ooblen    = mtd->oobavail;
+		ops.oobretlen = 0;
+		ops.ooboffs   = 1;
+		ops.datbuf    = NULL;
+		ops.oobbuf    = readbuf;
+		pr_info("attempting to read past end of device\n");
+		pr_info("an error is expected...\n");
+		err = mtd_read_oob(mtd, mtd->size - mtd->writesize, &ops);
+		if (mtd_is_bitflip(err))
+			err = 0;
+
+		if (err) {
+			pr_info("error occurred as expected\n");
+			err = 0;
+		} else {
+			pr_err("error: read past end of device\n");
+			errcnt += 1;
+		}
+	}
+
+	/* Fifth test: write / read across block boundaries */
+	pr_info("test 5 of 5\n");
+
+	/* Erase all eraseblocks */
+	err = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
+	if (err)
+		goto out;
+
+	/* Write all eraseblocks */
+	prandom_seed_state(&rnd_state, 11);
+	pr_info("writing OOBs of whole device\n");
+	for (i = 0; i < ebcnt - 1; ++i) {
+		int cnt = 2;
+		int pg;
+		size_t sz = mtd->oobavail;
+		if (bbt[i] || bbt[i + 1])
+			continue;
+		addr = (loff_t)(i + 1) * mtd->erasesize - mtd->writesize;
+		prandom_bytes_state(&rnd_state, writebuf, sz * cnt);
+		for (pg = 0; pg < cnt; ++pg) {
+			ops.mode      = MTD_OPS_AUTO_OOB;
+			ops.len       = 0;
+			ops.retlen    = 0;
+			ops.ooblen    = sz;
+			ops.oobretlen = 0;
+			ops.ooboffs   = 0;
+			ops.datbuf    = NULL;
+			ops.oobbuf    = writebuf + pg * sz;
+			err = mtd_write_oob(mtd, addr, &ops);
+			if (err)
+				goto out;
+			if (i % 256 == 0)
+				pr_info("written up to eraseblock %u\n", i);
+
+			err = mtdtest_relax();
+			if (err)
+				goto out;
+
+			addr += mtd->writesize;
+		}
+	}
+	pr_info("written %u eraseblocks\n", i);
+
+	/* Check all eraseblocks */
+	prandom_seed_state(&rnd_state, 11);
+	pr_info("verifying all eraseblocks\n");
+	for (i = 0; i < ebcnt - 1; ++i) {
+		if (bbt[i] || bbt[i + 1])
+			continue;
+		prandom_bytes_state(&rnd_state, writebuf, mtd->oobavail * 2);
+		addr = (loff_t)(i + 1) * mtd->erasesize - mtd->writesize;
+		ops.mode      = MTD_OPS_AUTO_OOB;
+		ops.len       = 0;
+		ops.retlen    = 0;
+		ops.ooblen    = mtd->oobavail * 2;
+		ops.oobretlen = 0;
+		ops.ooboffs   = 0;
+		ops.datbuf    = NULL;
+		ops.oobbuf    = readbuf;
+		err = mtd_read_oob(mtd, addr, &ops);
+		if (mtd_is_bitflip(err))
+			err = 0;
+
+		if (err)
+			goto out;
+		if (memcmpshow(addr, readbuf, writebuf,
+			       mtd->oobavail * 2)) {
+			pr_err("error: verify failed at %#llx\n",
+			       (long long)addr);
+			errcnt += 1;
+			if (errcnt > 1000) {
+				pr_err("error: too many errors\n");
+				goto out;
+			}
+		}
+		if (i % 256 == 0)
+			pr_info("verified up to eraseblock %u\n", i);
+
+		err = mtdtest_relax();
+		if (err)
+			goto out;
+	}
+	pr_info("verified %u eraseblocks\n", i);
+
+	pr_info("finished with %d errors\n", errcnt);
+out:
+	kfree(bbt);
+	kfree(writebuf);
+	kfree(readbuf);
+	put_mtd_device(mtd);
+	if (err)
+		pr_info("error %d occurred\n", err);
+	printk(KERN_INFO "=================================================\n");
+	return err;
+}
+module_init(mtd_oobtest_init);
+
+static void __exit mtd_oobtest_exit(void)
+{
+	return;
+}
+module_exit(mtd_oobtest_exit);
+
+MODULE_DESCRIPTION("Out-of-band test module");
+MODULE_AUTHOR("Adrian Hunter");
+MODULE_LICENSE("GPL");