[PATCH 2/3] Break endless loop in serialport_write().

[Stefan Tauner]

serialport_write could loop endlessly when used with a seemingly valid port
that does always return 0 on writes instead of an error. Give up after 10k tries.

Signed-off-by: Stefan Tauner 
---
 serial.c |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/serial.c b/serial.c
index 11a749c..a3cdefb 100644
--- a/serial.c
+++ b/serial.c
@@ -264,6 +264,7 @@ int serialport_write(unsigned char *buf, unsigned int writecnt)
 #else
    ssize_t tmp = 0;
 #endif
+	uint empty_writes = 10000;

while (writecnt > 0) {
 #ifdef _WIN32
@@ -275,9 +276,15 @@ int serialport_write(unsigned char *buf, unsigned int writecnt)
    		msg_perr("Serial port write error!\n");
    		return 1;
    	}
-		if (!tmp)
+		if (!tmp) {
    		msg_pdbg("Empty write\n");
-		writecnt -= tmp; 
+			empty_writes--;
+			if (empty_writes == 0) {
+				msg_perr("Serial port seems dead!\n");
+				return 1;
+			}
+		}
+		writecnt -= tmp;
    	buf += tmp;
    }