[MERGED] libosmocore[master]: serial: Open devie in non-blocking mode and then switch to b...

[Harald Welte]

Harald Welte has submitted this change and it was merged.

Change subject: serial: Open devie in non-blocking mode and then switch to blocking
......................................................................


serial: Open devie in non-blocking mode and then switch to blocking

There are some serial ports that apparently block during the open in
some circumstances.  We don't want that.  We want to either open it
immediately, or fail fast.

Change-Id: I626b138574bc50f4f4b09c4d609f3623ff512dff
---
M src/serial.c
1 file changed, 17 insertions(+), 3 deletions(-)

Approvals:
  Harald Welte: Looks good to me, approved
  Jenkins Builder: Verified



diff --git a/src/serial.c b/src/serial.c
index 66ee756..4403226 100644
--- a/src/serial.c
+++ b/src/serial.c
@@ -59,16 +59,30 @@
 int
 osmo_serial_init(const char *dev, speed_t baudrate)
 {
-	int rc, fd=0, v24;
+	int rc, fd=0, v24, flags;
 	struct termios tio;
 
-	/* Open device */
-	fd = open(dev, O_RDWR | O_NOCTTY);
+	/* Use nonblock as the device might block otherwise */
+	fd = open(dev, O_RDWR | O_NOCTTY | O_SYNC | O_NONBLOCK);
 	if (fd < 0) {
 		dbg_perror("open");
 		return -errno;
 	}
 
+	/* now put it into blcoking mode */
+	flags = fcntl(fd, F_GETFL, 0);
+	if (flags < 0) {
+		dbg_perror("fcntl get flags");
+		return -1;
+	}
+
+	flags &= ~O_NONBLOCK;
+	rc = fcntl(fd, F_SETFL, flags);
+	if (rc != 0) {
+		dbg_perror("fcntl set flags");
+		return -1;
+	}
+
 	/* Configure serial interface */
 	rc = tcgetattr(fd, &tio);
 	if (rc < 0) {

-- 
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Gerrit-MessageType: merged
Gerrit-Change-Id: I626b138574bc50f4f4b09c4d609f3623ff512dff
Gerrit-PatchSet: 1
Gerrit-Project: libosmocore
Gerrit-Branch: master
Gerrit-Owner: Harald Welte <laforge at gnumonks.org>
Gerrit-Reviewer: Harald Welte <laforge at gnumonks.org>
Gerrit-Reviewer: Jenkins Builder