From: Dongwoo Lee <dwoo08.lee@samsung.com>
Date: Tue, 1 Sep 2020 10:11:28 +0000 (+0900)
Subject: usb: Read until buffer is fully filled
X-Git-Tag: submit/tizen/20200902.012141^0
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4f1157dc54bf221d4e986886dbaec8ebb3a41daa;p=platform%2Fcore%2Fsystem%2Finitrd-flash.git

usb: Read until buffer is fully filled

Since a single read may not fill the buffer entirely, this makes try
to fill the buffer fully with loop.

Change-Id: Ic73daf50b060f37c773774108952dbdf30de07e1
Signed-off-by: Dongwoo Lee <dwoo08.lee@samsung.com>
---

diff --git a/src/usb.c b/src/usb.c
index 9705b90..0c36fa0 100644
--- a/src/usb.c
+++ b/src/usb.c
@@ -198,7 +198,20 @@ static const struct {
 
 static ssize_t usb_rx_data(int fd, void *buf, ssize_t len)
 {
-	return read(fd, buf, len);
+	ssize_t r, count = 0;
+
+	do {
+		r = read(fd, buf + count, len - count);
+		if (r < 0) {
+			if (errno == EINTR)
+				continue;
+			else
+				return r;
+		}
+		count += r;
+	} while (count < len);
+
+	return count;
 }
 
 static ssize_t usb_tx_data(int fd, void *buf, ssize_t len)