nandtest: Introduce multiple reads & check iterations

The current nandtest performs a simple test which consists of:

  1. erase block
  2. write data
  3. read and verify

In order to improve the nandtest strength, this commit adds a new parameter
to increase the number of "read and verify" iterations. In other words,
the test now consists of:

  1. erase block
  2. write data
  3. read and verify (N times)

This seem to apply more pressure on a NAND driver's ECC engine and has been
used to discover stability problems with an old OMAP2.

Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Acked-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

diff --git a/nandtest.c b/nandtest.c
index 31301d68b4d909a8f4394876a7d35fe6dfa25d0b..8ea39d3bcf5267acc947b8ee2fdc08e9cb67112d 100644 (file)
--- a/nandtest.c
+++ b/nandtest.c
@@ -24,6 +24,7 @@ void usage(int status)
                "  -m, --markbad        Mark blocks bad if they appear so\n"
                "  -s, --seed           Supply random seed\n"
                "  -p, --passes         Number of passes\n"
+               "  -r, --reads          Read & check iterations per pass (default=4)\n"
                "  -o, --offset         Start offset on flash\n"
                "  -l, --length         Length of flash to test\n"
                "  -k, --keep           Restore existing contents after test\n",
@@ -37,14 +38,11 @@ int fd;
 int markbad=0;
 int seed;
 
-void read_and_compare(loff_t ofs, unsigned char *data, unsigned char *rbuf)
+int read_and_compare(loff_t ofs, unsigned char *data, unsigned char *rbuf)
 {
        ssize_t len;
        int i;
 
-       printf("\r%08x: reading...", (unsigned)ofs);
-       fflush(stdout);
-
        len = pread(fd, rbuf, meminfo.erasesize, ofs);
        if (len < meminfo.erasesize) {
                printf("\n");
@@ -84,14 +82,16 @@ void read_and_compare(loff_t ofs, unsigned char *data, unsigned char *rbuf)
                                printf("Byte 0x%x is %02x should be %02x\n",
                                       i, rbuf[i], data[i]);
                }
-               exit(1);
+               return 1;
        }
+       return 0;
 }
 
-int erase_and_write(loff_t ofs, unsigned char *data, unsigned char *rbuf)
+int erase_and_write(loff_t ofs, unsigned char *data, unsigned char *rbuf, int nr_reads)
 {
        struct erase_info_user er;
        ssize_t len;
+       int i, read_errs = 0;
 
        printf("\r%08x: erasing... ", (unsigned)ofs);
        fflush(stdout);
@@ -127,7 +127,16 @@ int erase_and_write(loff_t ofs, unsigned char *data, unsigned char *rbuf)
                exit(1);
        }
 
-       read_and_compare(ofs, data, rbuf);
+       for (i=1; i<=nr_reads; i++) {
+               printf("\r%08x: reading (%d of %d)...", (unsigned)ofs, i, nr_reads);
+               fflush(stdout);
+               if (read_and_compare(ofs, data, rbuf))
+                       read_errs++;
+       }
+       if (read_errs) {
+               fprintf(stderr, "read/check %d of %d failed. seed %d\n", read_errs, nr_reads, seed);
+               return 1;
+       }
        return 0;
 }
 
@@ -141,6 +150,7 @@ int main(int argc, char **argv)
        unsigned char *wbuf, *rbuf, *kbuf;
        int pass;
        int nr_passes = 1;
+       int nr_reads = 4;
        int keep_contents = 0;
        uint32_t offset = 0;
        uint32_t length = -1;
@@ -148,7 +158,7 @@ int main(int argc, char **argv)
        seed = time(NULL);
 
        for (;;) {
-               static const char short_options[] = "hkl:mo:p:s:";
+               static const char short_options[] = "hkl:mo:p:r:s:";
                static const struct option long_options[] = {
                        { "help", no_argument, 0, 'h' },
                        { "markbad", no_argument, 0, 'm' },
@@ -156,6 +166,7 @@ int main(int argc, char **argv)
                        { "passes", required_argument, 0, 'p' },
                        { "offset", required_argument, 0, 'o' },
                        { "length", required_argument, 0, 'l' },
+                       { "reads", optional_argument, 0, 'r' },
                        { "keep", no_argument, 0, 'k' },
                        {0, 0, 0, 0},
                };
@@ -189,6 +200,10 @@ int main(int argc, char **argv)
                        nr_passes = atol(optarg);
                        break;
 
+               case 'r':
+                       nr_reads = atol(optarg);
+                       break;
+
                case 'o':
                        offset = atol(optarg);
                        break;
@@ -286,10 +301,10 @@ int main(int argc, char **argv)
                                        exit(1);
                                }
                        }
-                       if (erase_and_write(test_ofs, wbuf, rbuf))
+                       if (erase_and_write(test_ofs, wbuf, rbuf, nr_reads))
                                continue;
                        if (keep_contents)
-                               erase_and_write(test_ofs, kbuf, rbuf);
+                               erase_and_write(test_ofs, kbuf, rbuf, 1);
                }
                printf("\nFinished pass %d successfully\n", pass+1);
        }