MTD: tests: add mtd_oobtest

This test checks that OOB of a NAND MTD device works fine.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

1 files changed, 742 insertions, 0 deletions

diff --git a/drivers/mtd/tests/mtd_oobtest.c b/drivers/mtd/tests/mtd_oobtest.c
new file mode 100644
index 0000000..afbc3f8
--- /dev/null
+++ b/drivers/mtd/tests/mtd_oobtest.c
@@ -0,0 +1,742 @@
+/*
+ * 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>
+ */
+
+#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/sched.h>
+
+#define PRINT_PREF KERN_INFO "mtd_oobtest: "
+
+static int dev;
+module_param(dev, int, S_IRUGO);
+MODULE_PARM_DESC(dev, "MTD device number to use");
+
+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 unsigned long next = 1;
+
+static inline unsigned int simple_rand(void)
+{
+	next = next * 1103515245 + 12345;
+	return (unsigned int)((next / 65536) % 32768);
+}
+
+static inline void simple_srand(unsigned long seed)
+{
+	next = seed;
+}
+
+static void set_random_data(unsigned char *buf, size_t len)
+{
+	size_t i;
+
+	for (i = 0; i < len; ++i)
+		buf[i] = simple_rand();
+}
+
+static int erase_eraseblock(int ebnum)
+{
+	int err;
+	struct erase_info ei;
+	loff_t addr = ebnum * mtd->erasesize;
+
+	memset(&ei, 0, sizeof(struct erase_info));
+	ei.mtd  = mtd;
+	ei.addr = addr;
+	ei.len  = mtd->erasesize;
+
+	err = mtd->erase(mtd, &ei);
+	if (err) {
+		printk(PRINT_PREF "error %d while erasing EB %d\n", err, ebnum);
+		return err;
+	}
+
+	if (ei.state == MTD_ERASE_FAILED) {
+		printk(PRINT_PREF "some erase error occurred at EB %d\n",
+		       ebnum);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int erase_whole_device(void)
+{
+	int err;
+	unsigned int i;
+
+	printk(PRINT_PREF "erasing whole device\n");
+	for (i = 0; i < ebcnt; ++i) {
+		if (bbt[i])
+			continue;
+		err = erase_eraseblock(i);
+		if (err)
+			return err;
+		cond_resched();
+	}
+	printk(PRINT_PREF "erased %u eraseblocks\n", i);
+	return 0;
+}
+
+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 = ebnum * mtd->erasesize;
+
+	for (i = 0; i < pgcnt; ++i, addr += mtd->writesize) {
+		set_random_data(writebuf, use_len);
+		ops.mode      = MTD_OOB_AUTO;
+		ops.len       = 0;
+		ops.retlen    = 0;
+		ops.ooblen    = use_len;
+		ops.oobretlen = 0;
+		ops.ooboffs   = use_offset;
+		ops.datbuf    = 0;
+		ops.oobbuf    = writebuf;
+		err = mtd->write_oob(mtd, addr, &ops);
+		if (err || ops.oobretlen != use_len) {
+			printk(PRINT_PREF "error: writeoob failed at %#llx\n",
+			       (long long)addr);
+			printk(PRINT_PREF "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;
+
+	printk(PRINT_PREF "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)
+			printk(PRINT_PREF "written up to eraseblock %u\n", i);
+		cond_resched();
+	}
+	printk(PRINT_PREF "written %u eraseblocks\n", i);
+	return 0;
+}
+
+static int verify_eraseblock(int ebnum)
+{
+	int i;
+	struct mtd_oob_ops ops;
+	int err = 0;
+	loff_t addr = ebnum * mtd->erasesize;
+
+	for (i = 0; i < pgcnt; ++i, addr += mtd->writesize) {
+		set_random_data(writebuf, use_len);
+		ops.mode      = MTD_OOB_AUTO;
+		ops.len       = 0;
+		ops.retlen    = 0;
+		ops.ooblen    = use_len;
+		ops.oobretlen = 0;
+		ops.ooboffs   = use_offset;
+		ops.datbuf    = 0;
+		ops.oobbuf    = readbuf;
+		err = mtd->read_oob(mtd, addr, &ops);
+		if (err || ops.oobretlen != use_len) {
+			printk(PRINT_PREF "error: readoob failed at %#llx\n",
+			       (long long)addr);
+			errcnt += 1;
+			return err ? err : -1;
+		}
+		if (memcmp(readbuf, writebuf, use_len)) {
+			printk(PRINT_PREF "error: verify failed at %#llx\n",
+			       (long long)addr);
+			errcnt += 1;
+			if (errcnt > 1000) {
+				printk(PRINT_PREF "error: too many errors\n");
+				return -1;
+			}
+		}
+		if (use_offset != 0 || use_len < mtd->ecclayout->oobavail) {
+			int k;
+
+			ops.mode      = MTD_OOB_AUTO;
+			ops.len       = 0;
+			ops.retlen    = 0;
+			ops.ooblen    = mtd->ecclayout->oobavail;
+			ops.oobretlen = 0;
+			ops.ooboffs   = 0;
+			ops.datbuf    = 0;
+			ops.oobbuf    = readbuf;
+			err = mtd->read_oob(mtd, addr, &ops);
+			if (err || ops.oobretlen != mtd->ecclayout->oobavail) {
+				printk(PRINT_PREF "error: readoob failed at "
+				       "%#llx\n", (long long)addr);
+				errcnt += 1;
+				return err ? err : -1;
+			}
+			if (memcmp(readbuf + use_offset, writebuf, use_len)) {
+				printk(PRINT_PREF "error: verify failed at "
+				       "%#llx\n", (long long)addr);
+				errcnt += 1;
+				if (errcnt > 1000) {
+					printk(PRINT_PREF "error: too many "
+					       "errors\n");
+					return -1;
+				}
+			}
+			for (k = 0; k < use_offset; ++k)
+				if (readbuf[k] != 0xff) {
+					printk(PRINT_PREF "error: verify 0xff "
+					       "failed at %#llx\n",
+					       (long long)addr);
+					errcnt += 1;
+					if (errcnt > 1000) {
+						printk(PRINT_PREF "error: too "
+						       "many errors\n");
+						return -1;
+					}
+				}
+			for (k = use_offset + use_len;
+			     k < mtd->ecclayout->oobavail; ++k)
+				if (readbuf[k] != 0xff) {
+					printk(PRINT_PREF "error: verify 0xff "
+					       "failed at %#llx\n",
+					       (long long)addr);
+					errcnt += 1;
+					if (errcnt > 1000) {
+						printk(PRINT_PREF "error: too "
+						       "many errors\n");
+						return -1;
+					}
+				}
+		}
+		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 = ebnum * mtd->erasesize;
+	size_t len = mtd->ecclayout->oobavail * pgcnt;
+
+	set_random_data(writebuf, len);
+	ops.mode      = MTD_OOB_AUTO;
+	ops.len       = 0;
+	ops.retlen    = 0;
+	ops.ooblen    = len;
+	ops.oobretlen = 0;
+	ops.ooboffs   = 0;
+	ops.datbuf    = 0;
+	ops.oobbuf    = readbuf;
+	err = mtd->read_oob(mtd, addr, &ops);
+	if (err || ops.oobretlen != len) {
+		printk(PRINT_PREF "error: readoob failed at %#llx\n",
+		       (long long)addr);
+		errcnt += 1;
+		return err ? err : -1;
+	}
+	if (memcmp(readbuf, writebuf, len)) {
+		printk(PRINT_PREF "error: verify failed at %#llx\n",
+		       (long long)addr);
+		errcnt += 1;
+		if (errcnt > 1000) {
+			printk(PRINT_PREF "error: too many errors\n");
+			return -1;
+		}
+	}
+
+	return err;
+}
+
+static int verify_all_eraseblocks(void)
+{
+	int err;
+	unsigned int i;
+
+	printk(PRINT_PREF "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)
+			printk(PRINT_PREF "verified up to eraseblock %u\n", i);
+		cond_resched();
+	}
+	printk(PRINT_PREF "verified %u eraseblocks\n", i);
+	return 0;
+}
+
+static int is_block_bad(int ebnum)
+{
+	int ret;
+	loff_t addr = ebnum * mtd->erasesize;
+
+	ret = mtd->block_isbad(mtd, addr);
+	if (ret)
+		printk(PRINT_PREF "block %d is bad\n", ebnum);
+	return ret;
+}
+
+static int scan_for_bad_eraseblocks(void)
+{
+	int i, bad = 0;
+
+	bbt = kmalloc(ebcnt, GFP_KERNEL);
+	if (!bbt) {
+		printk(PRINT_PREF "error: cannot allocate memory\n");
+		return -ENOMEM;
+	}
+	memset(bbt, 0 , ebcnt);
+
+	printk(PRINT_PREF "scanning for bad eraseblocks\n");
+	for (i = 0; i < ebcnt; ++i) {
+		bbt[i] = is_block_bad(i) ? 1 : 0;
+		if (bbt[i])
+			bad += 1;
+		cond_resched();
+	}
+	printk(PRINT_PREF "scanned %d eraseblocks, %d are bad\n", i, bad);
+	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");
+	printk(PRINT_PREF "MTD device: %d\n", dev);
+
+	mtd = get_mtd_device(NULL, dev);
+	if (IS_ERR(mtd)) {
+		err = PTR_ERR(mtd);
+		printk(PRINT_PREF "error: cannot get MTD device\n");
+		return err;
+	}
+
+	if (mtd->type != MTD_NANDFLASH) {
+		printk(PRINT_PREF "this test requires NAND flash\n");
+		goto out;
+	}
+
+	tmp = mtd->size;
+	do_div(tmp, mtd->erasesize);
+	ebcnt = tmp;
+	pgcnt = mtd->erasesize / mtd->writesize;
+
+	printk(PRINT_PREF "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;
+	mtd->erasesize = mtd->erasesize;
+	readbuf = kmalloc(mtd->erasesize, GFP_KERNEL);
+	if (!readbuf) {
+		printk(PRINT_PREF "error: cannot allocate memory\n");
+		goto out;
+	}
+	writebuf = kmalloc(mtd->erasesize, GFP_KERNEL);
+	if (!writebuf) {
+		printk(PRINT_PREF "error: cannot allocate memory\n");
+		goto out;
+	}
+
+	err = scan_for_bad_eraseblocks();
+	if (err)
+		goto out;
+
+	use_offset = 0;
+	use_len = mtd->ecclayout->oobavail;
+	use_len_max = mtd->ecclayout->oobavail;
+	vary_offset = 0;
+
+	/* First test: write all OOB, read it back and verify */
+	printk(PRINT_PREF "test 1 of 5\n");
+
+	err = erase_whole_device();
+	if (err)
+		goto out;
+
+	simple_srand(1);
+	err = write_whole_device();
+	if (err)
+		goto out;
+
+	simple_srand(1);
+	err = verify_all_eraseblocks();
+	if (err)
+		goto out;
+
+	/*
+	 * Second test: write all OOB, a block at a time, read it back and
+	 * verify.
+	 */
+	printk(PRINT_PREF "test 2 of 5\n");
+
+	err = erase_whole_device();
+	if (err)
+		goto out;
+
+	simple_srand(3);
+	err = write_whole_device();
+	if (err)
+		goto out;
+
+	/* Check all eraseblocks */
+	simple_srand(3);
+	printk(PRINT_PREF "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)
+			printk(PRINT_PREF "verified up to eraseblock %u\n", i);
+		cond_resched();
+	}
+	printk(PRINT_PREF "verified %u eraseblocks\n", i);
+
+	/*
+	 * Third test: write OOB at varying offsets and lengths, read it back
+	 * and verify.
+	 */
+	printk(PRINT_PREF "test 3 of 5\n");
+
+	err = erase_whole_device();
+	if (err)
+		goto out;
+
+	/* Write all eraseblocks */
+	use_offset = 0;
+	use_len = mtd->ecclayout->oobavail;
+	use_len_max = mtd->ecclayout->oobavail;
+	vary_offset = 1;
+	simple_srand(5);
+	printk(PRINT_PREF "writing OOBs of whole device\n");
+	for (i = 0; i < ebcnt; ++i) {
+		if (bbt[i])
+			continue;
+		err = write_eraseblock(i);
+		if (err)
+			goto out;
+		if (i % 256 == 0)
+			printk(PRINT_PREF "written up to eraseblock %u\n", i);
+		cond_resched();
+	}
+	printk(PRINT_PREF "written %u eraseblocks\n", i);
+
+	/* Check all eraseblocks */
+	use_offset = 0;
+	use_len = mtd->ecclayout->oobavail;
+	use_len_max = mtd->ecclayout->oobavail;
+	vary_offset = 1;
+	simple_srand(5);
+	err = verify_all_eraseblocks();
+	if (err)
+		goto out;
+
+	use_offset = 0;
+	use_len = mtd->ecclayout->oobavail;
+	use_len_max = mtd->ecclayout->oobavail;
+	vary_offset = 0;
+
+	/* Fourth test: try to write off end of device */
+	printk(PRINT_PREF "test 4 of 5\n");
+
+	err = erase_whole_device();
+	if (err)
+		goto out;
+
+	addr0 = 0;
+	for (i = 0; bbt[i] && i < ebcnt; ++i)
+		addr0 += mtd->erasesize;
+
+	/* Attempt to write off end of OOB */
+	ops.mode      = MTD_OOB_AUTO;
+	ops.len       = 0;
+	ops.retlen    = 0;
+	ops.ooblen    = 1;
+	ops.oobretlen = 0;
+	ops.ooboffs   = mtd->ecclayout->oobavail;
+	ops.datbuf    = 0;
+	ops.oobbuf    = writebuf;
+	printk(PRINT_PREF "attempting to start write past end of OOB\n");
+	printk(PRINT_PREF "an error is expected...\n");
+	err = mtd->write_oob(mtd, addr0, &ops);
+	if (err) {
+		printk(PRINT_PREF "error occurred as expected\n");
+		err = 0;
+	} else {
+		printk(PRINT_PREF "error: can write past end of OOB\n");
+		errcnt += 1;
+	}
+
+	/* Attempt to read off end of OOB */
+	ops.mode      = MTD_OOB_AUTO;
+	ops.len       = 0;
+	ops.retlen    = 0;
+	ops.ooblen    = 1;
+	ops.oobretlen = 0;
+	ops.ooboffs   = mtd->ecclayout->oobavail;
+	ops.datbuf    = 0;
+	ops.oobbuf    = readbuf;
+	printk(PRINT_PREF "attempting to start read past end of OOB\n");
+	printk(PRINT_PREF "an error is expected...\n");
+	err = mtd->read_oob(mtd, addr0, &ops);
+	if (err) {
+		printk(PRINT_PREF "error occurred as expected\n");
+		err = 0;
+	} else {
+		printk(PRINT_PREF "error: can read past end of OOB\n");
+		errcnt += 1;
+	}
+
+	if (bbt[ebcnt - 1])
+		printk(PRINT_PREF "skipping end of device tests because last "
+		       "block is bad\n");
+	else {
+		/* Attempt to write off end of device */
+		ops.mode      = MTD_OOB_AUTO;
+		ops.len       = 0;
+		ops.retlen    = 0;
+		ops.ooblen    = mtd->ecclayout->oobavail + 1;
+		ops.oobretlen = 0;
+		ops.ooboffs   = 0;
+		ops.datbuf    = 0;
+		ops.oobbuf    = writebuf;
+		printk(PRINT_PREF "attempting to write past end of device\n");
+		printk(PRINT_PREF "an error is expected...\n");
+		err = mtd->write_oob(mtd, mtd->size - mtd->writesize, &ops);
+		if (err) {
+			printk(PRINT_PREF "error occurred as expected\n");
+			err = 0;
+		} else {
+			printk(PRINT_PREF "error: wrote past end of device\n");
+			errcnt += 1;
+		}
+
+		/* Attempt to read off end of device */
+		ops.mode      = MTD_OOB_AUTO;
+		ops.len       = 0;
+		ops.retlen    = 0;
+		ops.ooblen    = mtd->ecclayout->oobavail + 1;
+		ops.oobretlen = 0;
+		ops.ooboffs   = 0;
+		ops.datbuf    = 0;
+		ops.oobbuf    = readbuf;
+		printk(PRINT_PREF "attempting to read past end of device\n");
+		printk(PRINT_PREF "an error is expected...\n");
+		err = mtd->read_oob(mtd, mtd->size - mtd->writesize, &ops);
+		if (err) {
+			printk(PRINT_PREF "error occurred as expected\n");
+			err = 0;
+		} else {
+			printk(PRINT_PREF "error: read past end of device\n");
+			errcnt += 1;
+		}
+
+		err = erase_eraseblock(ebcnt - 1);
+		if (err)
+			goto out;
+
+		/* Attempt to write off end of device */
+		ops.mode      = MTD_OOB_AUTO;
+		ops.len       = 0;
+		ops.retlen    = 0;
+		ops.ooblen    = mtd->ecclayout->oobavail;
+		ops.oobretlen = 0;
+		ops.ooboffs   = 1;
+		ops.datbuf    = 0;
+		ops.oobbuf    = writebuf;
+		printk(PRINT_PREF "attempting to write past end of device\n");
+		printk(PRINT_PREF "an error is expected...\n");
+		err = mtd->write_oob(mtd, mtd->size - mtd->writesize, &ops);
+		if (err) {
+			printk(PRINT_PREF "error occurred as expected\n");
+			err = 0;
+		} else {
+			printk(PRINT_PREF "error: wrote past end of device\n");
+			errcnt += 1;
+		}
+
+		/* Attempt to read off end of device */
+		ops.mode      = MTD_OOB_AUTO;
+		ops.len       = 0;
+		ops.retlen    = 0;
+		ops.ooblen    = mtd->ecclayout->oobavail;
+		ops.oobretlen = 0;
+		ops.ooboffs   = 1;
+		ops.datbuf    = 0;
+		ops.oobbuf    = readbuf;
+		printk(PRINT_PREF "attempting to read past end of device\n");
+		printk(PRINT_PREF "an error is expected...\n");
+		err = mtd->read_oob(mtd, mtd->size - mtd->writesize, &ops);
+		if (err) {
+			printk(PRINT_PREF "error occurred as expected\n");
+			err = 0;
+		} else {
+			printk(PRINT_PREF "error: read past end of device\n");
+			errcnt += 1;
+		}
+	}
+
+	/* Fifth test: write / read across block boundaries */
+	printk(PRINT_PREF "test 5 of 5\n");
+
+	/* Erase all eraseblocks */
+	err = erase_whole_device();
+	if (err)
+		goto out;
+
+	/* Write all eraseblocks */
+	simple_srand(11);
+	printk(PRINT_PREF "writing OOBs of whole device\n");
+	for (i = 0; i < ebcnt - 1; ++i) {
+		int cnt = 2;
+		int pg;
+		size_t sz = mtd->ecclayout->oobavail;
+		if (bbt[i] || bbt[i + 1])
+			continue;
+		addr = (i + 1) * mtd->erasesize - mtd->writesize;
+		for (pg = 0; pg < cnt; ++pg) {
+			set_random_data(writebuf, sz);
+			ops.mode      = MTD_OOB_AUTO;
+			ops.len       = 0;
+			ops.retlen    = 0;
+			ops.ooblen    = sz;
+			ops.oobretlen = 0;
+			ops.ooboffs   = 0;
+			ops.datbuf    = 0;
+			ops.oobbuf    = writebuf;
+			err = mtd->write_oob(mtd, addr, &ops);
+			if (err)
+				goto out;
+			if (i % 256 == 0)
+				printk(PRINT_PREF "written up to eraseblock "
+				       "%u\n", i);
+			cond_resched();
+			addr += mtd->writesize;
+		}
+	}
+	printk(PRINT_PREF "written %u eraseblocks\n", i);
+
+	/* Check all eraseblocks */
+	simple_srand(11);
+	printk(PRINT_PREF "verifying all eraseblocks\n");
+	for (i = 0; i < ebcnt - 1; ++i) {
+		if (bbt[i] || bbt[i + 1])
+			continue;
+		set_random_data(writebuf, mtd->ecclayout->oobavail * 2);
+		addr = (i + 1) * mtd->erasesize - mtd->writesize;
+		ops.mode      = MTD_OOB_AUTO;
+		ops.len       = 0;
+		ops.retlen    = 0;
+		ops.ooblen    = mtd->ecclayout->oobavail * 2;
+		ops.oobretlen = 0;
+		ops.ooboffs   = 0;
+		ops.datbuf    = 0;
+		ops.oobbuf    = readbuf;
+		err = mtd->read_oob(mtd, addr, &ops);
+		if (err)
+			goto out;
+		if (memcmp(readbuf, writebuf, mtd->ecclayout->oobavail * 2)) {
+			printk(PRINT_PREF "error: verify failed at %#llx\n",
+			       (long long)addr);
+			errcnt += 1;
+			if (errcnt > 1000) {
+				printk(PRINT_PREF "error: too many errors\n");
+				goto out;
+			}
+		}
+		if (i % 256 == 0)
+			printk(PRINT_PREF "verified up to eraseblock %u\n", i);
+		cond_resched();
+	}
+	printk(PRINT_PREF "verified %u eraseblocks\n", i);
+
+	printk(PRINT_PREF "finished with %d errors\n", errcnt);
+out:
+	kfree(bbt);
+	kfree(writebuf);
+	kfree(readbuf);
+	put_mtd_device(mtd);
+	if (err)
+		printk(PRINT_PREF "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");