kfifo: add explicit error checking in all the examples

Provide a check in all the kfifo examples to validate the correct
execution of each testcase.

Signed-off-by: Andrea Righi <arighi@develer.com>
Acked-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/samples/kfifo/bytestream-example.c b/samples/kfifo/bytestream-example.c
index a94e6948b30d..178061e87ffe 100644
--- a/samples/kfifo/bytestream-example.c
+++ b/samples/kfifo/bytestream-example.c
@@ -44,7 +44,7 @@ static struct kfifo test;
 static DECLARE_KFIFO(test, unsigned char, FIFO_SIZE);
 #endif
 
-static unsigned char expected_result[FIFO_SIZE] = {
+static const unsigned char expected_result[FIFO_SIZE] = {
          3,  4,  5,  6,  7,  8,  9,  0,
          1, 20, 21, 22, 23, 24, 25, 26,
         27, 28, 29, 30, 31, 32, 33, 34,
@@ -90,9 +90,14 @@ static int __init testfunc(void)
 
         printk(KERN_INFO "queue len: %u\n", kfifo_len(&test));
 
+        /* show the first value without removing from the fifo */
+        if (kfifo_peek(&test, &i))
+                printk(KERN_INFO "%d\n", i);
+
         /* check the correctness of all values in the fifo */
         j = 0;
         while (kfifo_get(&test, &i)) {
+                printk(KERN_INFO "item = %d\n", i);
                 if (i != expected_result[j++]) {
                         printk(KERN_WARNING "value mismatch: test failed\n");
                         return -EIO;