From 86cf5bd1e0633f16c722500bd9717d999a7e2473 Mon Sep 17 00:00:00 2001
From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Date: Thu, 28 Feb 2013 10:42:09 +0100
Subject: flash_otp_write: fix writing to NAND in presence of partial reads
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When doing something like:
{ printf "\xff"; printf "\xfe"; } | flash_otp_write -u /dev/mtd0 0
flash_otp_write might see only a single byte when reading from stdin for
the first tim. In this case (and without this patch) it pads to
$writesize with '\xff's and writes that out. In the next iteration it
reads the 2nd byte, pads and writes again. So the 2nd byte is written to
offset $writesize instead of 1.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
---
flash_otp_write.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/flash_otp_write.c b/flash_otp_write.c
index 56769ec..3515eee 100644
--- a/flash_otp_write.c
+++ b/flash_otp_write.c
@@ -16,6 +16,23 @@
#include <common.h>
#include <mtd/mtd-user.h>
+ssize_t xread(int fd, void *buf, size_t count)
+{
+ ssize_t ret, done = 0;
+
+retry:
+ ret = read(fd, buf + done, count - done);
+ if (ret < 0)
+ return ret;
+
+ done += ret;
+
+ if (ret == 0 /* EOF */ || done == count)
+ return done;
+ else
+ goto retry;
+}
+
int main(int argc,char *argv[])
{
int fd, val, ret, size, wrote, len;
@@ -67,7 +84,7 @@ int main(int argc,char *argv[])
len = 256;
wrote = 0;
- while ((size = read(0, buf, len))) {
+ while ((size = xread(0, buf, len))) {
if (size < 0) {
perror("read()");
return errno;
--
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