Commit afc0ea1b authored by Roger Quadros's avatar Roger Quadros Committed by Brian Norris

mtd: mtd_oobtest: add bitflip_limit parameter

It is common for NAND devices to have bitflip errors.
Add a bitflip_limit parameter to specify how many bitflips per
page we can tolerate without flagging an error.
By default zero bitflips are tolerated.
Signed-off-by: default avatarRoger Quadros <rogerq@ti.com>
Signed-off-by: default avatarSekhar Nori <nsekhar@ti.com>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
parent 5a66088b
......@@ -34,8 +34,11 @@
#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;
......@@ -115,24 +118,27 @@ static int write_whole_device(void)
return 0;
}
/* Display the address, offset and data bytes at comparison failure */
static int memcmpshow(loff_t addr, const void *cs, const void *ct, size_t count)
/*
* Display the address, offset and data bytes at comparison failure.
* Return number of bitflips encountered.
*/
static size_t memcmpshow(loff_t addr, const void *cs, const void *ct, size_t count)
{
const unsigned char *su1, *su2;
int res;
int ret = 0;
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%x] 0x%x -> 0x%x diff 0x%x\n",
(unsigned long)addr, i, *su1, *su2, res);
ret = 1;
bitflips += hweight8(res);
}
}
return ret;
return bitflips;
}
static int verify_eraseblock(int ebnum)
......@@ -141,6 +147,7 @@ static int verify_eraseblock(int ebnum)
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) {
......@@ -159,9 +166,11 @@ static int verify_eraseblock(int ebnum)
errcnt += 1;
return err ? err : -1;
}
if (memcmpshow(addr, readbuf,
bitflips = memcmpshow(addr, readbuf,
writebuf + (use_len_max * i) + use_offset,
use_len)) {
use_len);
if (bitflips > bitflip_limit) {
pr_err("error: verify failed at %#llx\n",
(long long)addr);
errcnt += 1;
......@@ -169,7 +178,10 @@ static int verify_eraseblock(int ebnum)
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->ecclayout->oobavail) {
int k;
......@@ -188,9 +200,10 @@ static int verify_eraseblock(int ebnum)
errcnt += 1;
return err ? err : -1;
}
if (memcmpshow(addr, readbuf + use_offset,
bitflips = memcmpshow(addr, readbuf + use_offset,
writebuf + (use_len_max * i) + use_offset,
use_len)) {
use_len);
if (bitflips > bitflip_limit) {
pr_err("error: verify failed at %#llx\n",
(long long)addr);
errcnt += 1;
......@@ -198,7 +211,10 @@ static int verify_eraseblock(int ebnum)
pr_err("error: too many errors\n");
return -1;
}
} else if (bitflips) {
pr_info("ignoring error as within bitflip_limit\n");
}
for (k = 0; k < use_offset; ++k)
if (readbuf[k] != 0xff) {
pr_err("error: verify 0xff "
......@@ -237,6 +253,9 @@ static int verify_eraseblock_in_one_go(int ebnum)
int err = 0;
loff_t addr = (loff_t)ebnum * mtd->erasesize;
size_t len = mtd->ecclayout->oobavail * pgcnt;
size_t oobavail = mtd->ecclayout->oobavail;
size_t bitflips;
int i;
prandom_bytes_state(&rnd_state, writebuf, len);
ops.mode = MTD_OPS_AUTO_OOB;
......@@ -247,6 +266,8 @@ static int verify_eraseblock_in_one_go(int ebnum)
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 (err || ops.oobretlen != len) {
pr_err("error: readoob failed at %#llx\n",
......@@ -254,7 +275,12 @@ static int verify_eraseblock_in_one_go(int ebnum)
errcnt += 1;
return err ? err : -1;
}
if (memcmpshow(addr, readbuf, writebuf, len)) {
/* 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;
......@@ -262,6 +288,9 @@ static int verify_eraseblock_in_one_go(int ebnum)
pr_err("error: too many errors\n");
return -1;
}
} else if (bitflips) {
pr_info("ignoring error as within bitflip_limit\n");
}
}
return err;
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment