[PATCH] nandwrite: Factor out buffer checking code
Marek Vasut
marex at denx.de
Wed Dec 7 20:13:42 PST 2016
Pull the buffer content checking code into separate function and
simplify the code invoking it slightly.
Signed-off-by: Marek Vasut <marex at denx.de>
Cc: Boris Brezillon <boris.brezillon at free-electrons.com>
Cc: David Oberhollenzer <david.oberhollenzer at sigma-star.at>
Cc: Kees Trommel <ctrommel at aimvalley.nl>
---
NOTE: This is only compile-tested.
---
nand-utils/nandwrite.c | 42 ++++++++++++++++++++++++++++--------------
1 file changed, 28 insertions(+), 14 deletions(-)
diff --git a/nand-utils/nandwrite.c b/nand-utils/nandwrite.c
index b376869..c5bd1c2 100644
--- a/nand-utils/nandwrite.c
+++ b/nand-utils/nandwrite.c
@@ -231,6 +231,31 @@ static void erase_buffer(void *buffer, size_t size)
memset(buffer, kEraseByte, size);
}
+/* Check whether buffer is filled with character 'pattern' */
+static int buffer_check_pattern(unsigned char *buffer, size_t size,
+ unsigned char pattern)
+{
+ /* Invalid input */
+ if (!buffer || (size == 0))
+ return 0;
+
+ /* No match on first byte */
+ if (*buffer != pattern)
+ return 0;
+
+ /* First byte matched and buffer is 1 byte long, OK. */
+ if (size == 1)
+ return 1;
+
+ /*
+ * Check buffer longer than 1 byte. We already know that buffer[0]
+ * matches the pattern, so the test below only checks whether the
+ * buffer[0...size-2] == buffer[1...size-1] , which is a test for
+ * whether the buffer is filled with constant value.
+ */
+ return !memcmp(buffer, buffer + 1, size - 1);
+}
+
/*
* Main program
*/
@@ -523,18 +548,8 @@ int main(int argc, char * const argv[])
}
}
- allffs = 0;
- if (skipallffs)
- {
- for (ii = 0; ii < mtd.min_io_size; ii += sizeof(uint32_t))
- {
- if (*(uint32_t*)(writebuf + ii) != 0xffffffff)
- break;
- }
- if (ii == mtd.min_io_size)
- allffs = 1;
- }
- if (!allffs) {
+ ret = 0;
+ if (!skipallffs || !buffer_check_pattern(writebuf, mtd.min_io_size, 0xff)) {
/* Write out data */
ret = mtd_write(mtd_desc, &mtd, fd, mtdoffset / mtd.eb_size,
mtdoffset % mtd.eb_size,
@@ -543,9 +558,8 @@ int main(int argc, char * const argv[])
writeoob ? oobbuf : NULL,
writeoob ? mtd.oob_size : 0,
write_mode);
- } else {
- ret = 0;
}
+
if (ret) {
long long i;
if (errno != EIO) {
--
2.10.2
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