mtd: mtd_oobtest: Show the verification error location and data

Add a function memcmpshow() that compares the 2 data buffers
and shows the address:offset and data bytes on comparison failure.
This function  does not break at a comparison failure but runs the
check for the whole data buffer.

Use memcmpshow() instead of memcmp() for all the verification paths.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

1 files changed, 29 insertions, 7 deletions

diff --git a/drivers/mtd/tests/oobtest.c b/drivers/mtd/tests/oobtest.c
index dc4f9602b97e..edd859d96d85 100644
--- a/drivers/mtd/tests/oobtest.c
+++ b/drivers/mtd/tests/oobtest.c
@@ -115,6 +115,26 @@ 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)
+{
+        const unsigned char *su1, *su2;
+        int res;
+        int ret = 0;
+        size_t i = 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;
+                }
+        }
+
+        return ret;
+}
+
 static int verify_eraseblock(int ebnum)
 {
         int i;
@@ -139,8 +159,9 @@ static int verify_eraseblock(int ebnum)
                         errcnt += 1;
                         return err ? err : -1;
                 }
-                if (memcmp(readbuf, writebuf + (use_len_max * i) + use_offset,
-                           use_len)) {
+                if (memcmpshow(addr, readbuf,
+                               writebuf + (use_len_max * i) + use_offset,
+                               use_len)) {
                         pr_err("error: verify failed at %#llx\n",
                                (long long)addr);
                         errcnt += 1;
@@ -167,9 +188,9 @@ static int verify_eraseblock(int ebnum)
                                 errcnt += 1;
                                 return err ? err : -1;
                         }
-                        if (memcmp(readbuf + use_offset,
-                                   writebuf + (use_len_max * i) + use_offset,
-                                   use_len)) {
+                        if (memcmpshow(addr, readbuf + use_offset,
+                                       writebuf + (use_len_max * i) + use_offset,
+                                       use_len)) {
                                 pr_err("error: verify failed at %#llx\n",
                                                 (long long)addr);
                                 errcnt += 1;
@@ -233,7 +254,7 @@ static int verify_eraseblock_in_one_go(int ebnum)
                 errcnt += 1;
                 return err ? err : -1;
         }
-        if (memcmp(readbuf, writebuf, len)) {
+        if (memcmpshow(addr, readbuf, writebuf, len)) {
                 pr_err("error: verify failed at %#llx\n",
                        (long long)addr);
                 errcnt += 1;
@@ -610,7 +631,8 @@ static int __init mtd_oobtest_init(void)
                 err = mtd_read_oob(mtd, addr, &ops);
                 if (err)
                         goto out;
-                if (memcmp(readbuf, writebuf, mtd->ecclayout->oobavail * 2)) {
+                if (memcmpshow(addr, readbuf, writebuf,
+                               mtd->ecclayout->oobavail * 2)) {
                         pr_err("error: verify failed at %#llx\n",
                                (long long)addr);
                         errcnt += 1;