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 about 125 ms i.e. 250 tries with a period of 500 us.
Signed-off-by: Stefan Tauner stefan.tauner@student.tuwien.ac.at --- serial.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/serial.c b/serial.c index 7e47dcc..794763e 100644 --- a/serial.c +++ b/serial.c @@ -262,6 +262,7 @@ int serialport_write(unsigned char *buf, unsigned int writecnt) #else ssize_t tmp = 0; #endif + unsigned int empty_writes = 250; /* results in a ca. 125ms timeout */
while (writecnt > 0) { #ifdef _WIN32 @@ -273,9 +274,16 @@ int serialport_write(unsigned char *buf, unsigned int writecnt) msg_perr("Serial port write error!\n"); return 1; } - if (!tmp) - msg_pdbg("Empty write\n"); - writecnt -= tmp; + if (!tmp) { + msg_pdbg2("Empty write\n"); + empty_writes--; + programmer_delay(500); + if (empty_writes == 0) { + msg_perr("Serial port seems dead!\n"); + return 1; + } + } + writecnt -= tmp; buf += tmp; }