nandwrite: correct data reading

The "read" syscall does not necessarily return all the requested
data, in which case the caller has to try again and read more.
Take this into account when reading input data.

This patch is an improved vestion of the original patch sent by
Hai Zaar.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Tested-by: Hai Zaar <haizaar@codefidence.com>

1 files changed, 23 insertions, 8 deletions

diff --git a/nandwrite.c b/nandwrite.c
index fc23e85..0b2a9ee 100644
--- a/nandwrite.c
+++ b/nandwrite.c
@@ -260,6 +260,7 @@ int main(int argc, char * const argv[])
 	int ret, readlen;
 	int oobinfochanged = 0;
 	struct nand_oobinfo old_oobinfo;
+	int readcnt = 0;
 
 	process_options(argc, argv);
 
@@ -477,6 +478,8 @@ int main(int argc, char * const argv[])
 		readlen = meminfo.writesize;
 
 		if (ifd != STDIN_FILENO) {
+			int tinycnt = 0;
+
 			if (pad && (imglen < readlen))
 			{
 				readlen = imglen;
@@ -484,11 +487,15 @@ int main(int argc, char * const argv[])
 			}
 
 			/* Read Page Data from input file */
-			if ((cnt = read(ifd, writebuf, readlen)) != readlen) {
-				if (cnt == 0)	// EOF
+			while(tinycnt < readlen) {
+				cnt = read(ifd, writebuf + tinycnt, readlen - tinycnt);
+				if (cnt == 0) { // EOF
 					break;
-				perror ("File I/O error on input file");
-				goto closeall;
+				} else if (cnt < 0) {
+					perror ("File I/O error on input file");
+					goto closeall;
+				}
+				tinycnt += cnt;
 			}
 		} else {
 			int tinycnt = 0;
@@ -522,11 +529,19 @@ int main(int argc, char * const argv[])
 		}
 
 		if (writeoob) {
-			/* Read OOB data from input file, exit on failure */
-			if ((cnt = read(ifd, oobreadbuf, meminfo.oobsize)) != meminfo.oobsize) {
-				perror ("File I/O error on input file");
-				goto closeall;
+			int tinycnt = 0;
+
+			while(tinycnt < readlen) {
+				cnt = read(ifd, oobreadbuf + tinycnt, meminfo.oobsize - tinycnt);
+				if (cnt == 0) { // EOF
+					break;
+				} else if (cnt < 0) {
+					perror ("File I/O error on input file");
+					goto closeall;
+				}
+				tinycnt += cnt;
 			}
+
 			if (!noecc) {
 				int i, start, len;
 				/*