[PATCH v4] mtd: torturetest: add the support for random data pattern

[Huang Shijie]

On Wed, Feb 13, 2013 at 7:26 PM, Ezequiel Garcia
<ezequiel.garcia at free-electrons.com> wrote:
> Hi Huang,
>
> On Tue, Feb 05, 2013 at 05:06:39PM +0800, Huang Shijie wrote:
>> Add a new module parameter 'pattern'. The meaning of the pattern is:
>>   (1) pattern == 0 for 55/AA pattern.
>>   (2) pattern < 0 for random pattern.
>>   (3) pattern > 0 for random pattern too, the value of the pattern is used
>>       as the seed for the random generator.
>>
>> Signed-off-by: Huang Shijie <b32955 at freescale.com>
>> ---
>> v1 --> v2:
>>    add seed support.
>>
>> v2 --> v3:
>>    fix a type in pr_info
>>
>> v3 --> v4:
>>    fix a confusing description.
>> ---
>>  drivers/mtd/tests/mtd_torturetest.c |   82 +++++++++++++++++++++++++---------
>>  1 files changed, 60 insertions(+), 22 deletions(-)
>>
>> diff --git a/drivers/mtd/tests/mtd_torturetest.c b/drivers/mtd/tests/mtd_torturetest.c
>> index 516cf66..671e8dd 100644
>> --- a/drivers/mtd/tests/mtd_torturetest.c
>> +++ b/drivers/mtd/tests/mtd_torturetest.c
>> @@ -32,6 +32,7 @@
>>  #include <linux/mtd/mtd.h>
>>  #include <linux/slab.h>
>>  #include <linux/sched.h>
>> +#include <linux/random.h>
>>
>>  #define RETRIES 3
>>
>> @@ -64,6 +65,13 @@ module_param(cycles_count, uint, S_IRUGO);
>>  MODULE_PARM_DESC(cycles_count, "how many erase cycles to do "
>>                              "(infinite by default)");
>>
>> +static int pattern;
>> +module_param(pattern, int, S_IRUGO);
>> +MODULE_PARM_DESC(pattern, "0 for 55/AA pattern(default);"
>> +                     "less then 0 for random pattern;"
>> +                     "greater then 0 for random pattern too, "
>> +                     "the value of the parameter is the seed.");
>> +
>>  static struct mtd_info *mtd;
>>
>>  /* This buffer contains 0x555555...0xAAAAAA... pattern */
>> @@ -72,6 +80,8 @@ static unsigned char *patt_5A5;
>>  static unsigned char *patt_A5A;
>>  /* This buffer contains all 0xFF bytes */
>>  static unsigned char *patt_FF;
>> +/* This buffer contains the random data. */
>> +static unsigned char *patt_rd;
>>  /* This a temporary buffer is use when checking data */
>>  static unsigned char *check_buf;
>>  /* How many erase cycles were done */
>> @@ -228,6 +238,12 @@ static int __init tort_init(void)
>>               pr_info("torturing just %d pages per eraseblock\n",
>>                       pgcnt);
>>       pr_info("write verify %s\n", check ? "enabled" : "disabled");
>> +     if (pattern == 0)
>> +             pr_info("Test pattern is 55/AA.\n");
>> +     else if (pattern < 0)
>> +             pr_info("Test pattern is random.\n");
>> +     else
>> +             pr_info("Test pattern is random, seed is 0x%x.\n", pattern);
>>
>>       mtd = get_mtd_device(NULL, dev);
>>       if (IS_ERR(mtd)) {
>> @@ -249,16 +265,24 @@ static int __init tort_init(void)
>>       }
>>
>>       err = -ENOMEM;
>> -     patt_5A5 = kmalloc(mtd->erasesize, GFP_KERNEL);
>> -     if (!patt_5A5) {
>> -             pr_err("error: cannot allocate memory\n");
>
> Once again: you don't want to print this message!
> In case the kmalloc actually fails, your "cannot allocate memory"
> message won't be of any use to anyone.
>

got it.
thanks.

Huang Shijie