serprog: clear NDELAY flag only once after opening the port
Change sp_openserport() to directly clear the O_NONBLOCK flag that
is potentially set by opening the device with O_NDELAY instead of
clearing ALL flags in serialport_config() unconditionally.
Corresponding to flashrom svn r1905.
Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Urja Rannikko <urjaman@gmail.com>
diff --git a/serial.c b/serial.c
index 94f9b7d..63774a5 100644
--- a/serial.c
+++ b/serial.c
@@ -183,10 +183,6 @@
msg_pdbg("Baud rate is %ld.\n", dcb.BaudRate);
#else
struct termios wanted, observed;
- if (fcntl(fd, F_SETFL, 0) != 0) {
- msg_perr_strerror("Could not clear serial port mode: ");
- return 1;
- }
if (tcgetattr(fd, &observed) != 0) {
msg_perr_strerror("Could not fetch original serial port configuration: ");
return 1;
@@ -254,11 +250,23 @@
}
return fd;
#else
- fd = open(dev, O_RDWR | O_NOCTTY | O_NDELAY);
+ fd = open(dev, O_RDWR | O_NOCTTY | O_NDELAY); // Use O_NDELAY to ignore DCD state
if (fd < 0) {
msg_perr_strerror("Cannot open serial port: ");
return SER_INV_FD;
}
+
+ /* Ensure that we use blocking I/O */
+ const int flags = fcntl(fd, F_GETFL);
+ if (flags == -1) {
+ msg_perr_strerror("Could not get serial port mode: ");
+ return SER_INV_FD;
+ }
+ if (fcntl(fd, F_SETFL, flags & ~O_NONBLOCK) != 0) {
+ msg_perr_strerror("Could not set serial port mode to blocking: ");
+ return SER_INV_FD;
+ }
+
if (serialport_config(fd, baud) != 0) {
close(fd);
return SER_INV_FD;