[gpsd-dev] [PATCH 2/3] Ensure UBX device is actually switched to binary mode

[Chris Lawrence]

The message from the device announcing the correct port to connect to
in response to UBX-CFG-PRT may arrive after the attempt to configure
the output. This patch ensures a second UBX-CFG-PRT command is sent if
the response indicates the initial guess is wrong (for example, on my
MacBook, the device is attached to /dev/tty.usbmodemNNNN which is
guessed to be a UART but is actually USB).

I also took the liberty of simplifying the logic a bit; in particular
there's no need to clear bits that are already clear when setting the
mode, so the code can be simplified quite a bit.

Signed-off-by: Chris Lawrence <address@hidden>
---
 driver_ubx.c | 32 +++++++++++++++++++-------------
 1 file changed, 19 insertions(+), 13 deletions(-)

diff --git a/driver_ubx.c b/driver_ubx.c
index 05edc594..525db53a 100644
--- a/driver_ubx.c
+++ b/driver_ubx.c
@@ -719,9 +719,20 @@ gps_mask_t ubx_parse(struct gps_device_t * session, 
unsigned char *buf,
        break;
 
     case UBX_CFG_PRT:
-       session->driver.ubx.port_id = (unsigned 
char)buf[UBX_MESSAGE_DATA_OFFSET + 0];
-       gpsd_log(&session->context->errout, LOG_INF, "UBX_CFG_PRT: port %d\n",
-                session->driver.ubx.port_id);
+        if ( session->driver.ubx.port_id != (unsigned 
char)buf[UBX_MESSAGE_DATA_OFFSET + 0] ) {
+           session->driver.ubx.port_id = (unsigned 
char)buf[UBX_MESSAGE_DATA_OFFSET + 0];
+           gpsd_log(&session->context->errout, LOG_INF,
+                    "UBX_CFG_PRT: port %d\n", session->driver.ubx.port_id);
+
+#ifdef RECONFIGURE_ENABLE
+           /* Need to reinitialize since port changed */
+           if (session->mode == O_OPTIMIZE) {
+               ubx_mode(session, MODE_BINARY);
+           } else {
+               ubx_mode(session, MODE_NMEA);
+           }
+#endif /* RECONFIGURE_ENABLE */
+       }
        break;
 
     case UBX_TIM_TP:
@@ -912,9 +923,9 @@ static void ubx_cfg_prt(struct gps_device_t *session,
      * has port ID 3 the way it ought to.
      */
     else if (strstr(session->gpsdata.dev.path, "/ACM") != NULL)
-       buf[0] = USB_ID;
+       session->driver.ubx.port_id = buf[0] = USB_ID;
     else
-       buf[0] = USART1_ID;
+       session->driver.ubx.port_id = buf[0] = USART1_ID;
 
     putle32(buf, 8, speed);
 
@@ -973,6 +984,9 @@ static void ubx_cfg_prt(struct gps_device_t *session,
     /* enable all input protocols by default */
     buf[12] = NMEA_PROTOCOL_MASK | UBX_PROTOCOL_MASK | RTCM_PROTOCOL_MASK;
 
+    buf[outProtoMask] = (mode == MODE_NMEA ? NMEA_PROTOCOL_MASK : 
UBX_PROTOCOL_MASK);
+    (void)ubx_write(session, 0x06u, 0x00, buf, sizeof(buf));
+    
     /* selectively enable output protocols */
     if (mode == MODE_NMEA) {
        /*
@@ -1039,9 +1053,6 @@ static void ubx_cfg_prt(struct gps_device_t *session,
        msg[1] = 0x08;          /* msg id  = ZDA */
        msg[2] = 0x01;          /* rate */
        (void)ubx_write(session, 0x06u, 0x01, msg, 3);
-
-       buf[outProtoMask] &= ~UBX_PROTOCOL_MASK;
-       buf[outProtoMask] |= NMEA_PROTOCOL_MASK;
     } else { /* MODE_BINARY */
        /*
         * Just enabling the UBX protocol for output is not enough to
@@ -1135,12 +1146,7 @@ static void ubx_cfg_prt(struct gps_device_t *session,
        msg[2] = 0x00;          /* rate */
        (void)ubx_write(session, 0x06u, 0x01, msg, 3);
 #endif /* __UNUSED __ */
-
-       buf[outProtoMask] &= ~NMEA_PROTOCOL_MASK;
-       buf[outProtoMask] |= UBX_PROTOCOL_MASK;
     }
-
-    (void)ubx_write(session, 0x06u, 0x00, buf, sizeof(buf));
 }
 
 static void ubx_mode(struct gps_device_t *session, int mode)
-- 
2.14.3 (Apple Git-98)


-- 
Chris Lawrence <address@hidden> - http://blog.lordsutch.com/