Make sure writes complete.

sw/airborne/boards/ardrone/actuators_ardrone2_raw.c

@@ -33,6 +33,7 @@
 #include "mcu_periph/gpio.h"
 #include "led_hw.h"
 #include "mcu_periph/sys_time.h"
+#include "navdata.h" // for full_write
 
 #include <stdio.h>   /* Standard input/output definitions */
 #include <string.h>  /* String function definitions */
@@ -157,7 +158,11 @@ void actuators_ardrone_init(void)
 }
 
 int actuators_ardrone_cmd(uint8_t cmd, uint8_t *reply, int replylen) {
-  write(actuator_ardrone2_raw_fd, &cmd, 1);
+  if (full_write(actuator_ardrone2_raw_fd, &cmd, 1) < 0)
+  {
+    perror("actuators_ardrone_cmd: write failed");
+    return -1;
+  }
   return read(actuator_ardrone2_raw_fd, reply, replylen);
 }
 
@@ -241,7 +246,7 @@ void actuators_ardrone_set_pwm(uint16_t pwm0, uint16_t pwm1, uint16_t pwm2, uint
   cmd[2] = ((pwm1&0x1ff)<<3) | ((pwm2&0x1ff)>>6);
   cmd[3] = ((pwm2&0x1ff)<<2) | ((pwm3&0x1ff)>>7);
   cmd[4] = ((pwm3&0x1ff)<<1);
-  write(actuator_ardrone2_raw_fd, cmd, 5);
+  full_write(actuator_ardrone2_raw_fd, cmd, 5);
   RunOnceEvery(20,actuators_ardrone_led_run());
 }
 
@@ -270,7 +275,7 @@ void actuators_ardrone_set_leds(uint8_t led0, uint8_t led1, uint8_t led2, uint8_
   cmd[0]=0x60 | ((led0&1)<<4) | ((led1&1)<<3) | ((led2&1)<<2) | ((led3&1) <<1);
   cmd[1]=((led0&2)<<3) | ((led1&2)<<2) | ((led2&2)<<1) | ((led3&2)<<0);
 
-  write(actuator_ardrone2_raw_fd, cmd, 2);
+  full_write(actuator_ardrone2_raw_fd, cmd, 2);
 }
 
 void actuators_ardrone_close(void)

sw/airborne/boards/ardrone/navdata.c

@@ -56,23 +56,29 @@ static int nav_fd;
 
 measures_t navdata;
 
-static void navdata_write(const uint8_t *buf, size_t count)
+// FIXME(ben): there must be a better home for this
+ssize_t full_write(int fd, const uint8_t *buf, size_t count)
 {
   size_t written = 0;
 
   while(written < count)
   {
-    ssize_t n = write(nav_fd, buf + written, count - written);
+    ssize_t n = write(fd, buf + written, count - written);
     if (n < 0)
     {
       if (errno == EAGAIN || errno == EWOULDBLOCK)
 	continue;
-      perror("navdata_write: Write failed");
-      // FIXME: what's sensible to do at this point?
-      return;
+      return n;
     }
     written += n;
   }
+  return written;
+}
+
+static void navdata_write(const uint8_t *buf, size_t count)
+{
+  if (full_write(nav_fd, buf, count) < 0)
+    perror("navdata_write: Write failed");
 }
 
 int navdata_init()

sw/airborne/boards/ardrone/navdata.h

@@ -31,6 +31,7 @@
 #define NAVDATA_H_
 
 #include <stdint.h>
+#include <sys/types.h>
 
 typedef struct
 {
@@ -114,4 +115,6 @@ int16_t navdata_getHeight(void);
 
 void acquire_baro_calibration(void);
 
+ssize_t full_write(int fd, const uint8_t *buf, size_t count);
+
 #endif /* NAVDATA_H_ */