altos: Allow setting telemetry interval to zero without crashing

Setting telemetry interval to zero means disable telemetry, but the
code was using the zero value to compute a bunch of packet delays,
which involved dividing by the interval value causing a crash when it
was zero. Skip those subsequent computations as they won't be used
anyways.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/kernel/ao_telemetry.c b/src/kernel/ao_telemetry.c
index d567f9c2a3604c0a3a073432b869bd7204d8f92e..1fd4037f540b8d0d01618b6a22672cd613bb187b 100644 (file)
--- a/src/kernel/ao_telemetry.c
+++ b/src/kernel/ao_telemetry.c
@@ -636,45 +636,47 @@ ao_telemetry_set_interval(uint16_t interval)
                interval = min_interval[ao_config.radio_rate];
 #endif
        ao_telemetry_interval = interval;
+       if (interval) {
 #if AO_SEND_MEGA
-       if (interval > 1)
-               ao_telemetry_mega_data_max = 1;
-       else
-               ao_telemetry_mega_data_max = 2;
-       if (ao_telemetry_mega_data_max > cur)
-               cur++;
-       ao_telemetry_mega_data_cur = cur;
+               if (interval > 1)
+                       ao_telemetry_mega_data_max = 1;
+               else
+                       ao_telemetry_mega_data_max = 2;
+               if (ao_telemetry_mega_data_max > cur)
+                       cur++;
+               ao_telemetry_mega_data_cur = cur;
 #endif
 #if AO_SEND_METRUM
-       ao_telemetry_metrum_data_max = (int16_t) (AO_SEC_TO_TICKS(1) / interval);
-       if (ao_telemetry_metrum_data_max > cur)
-               cur++;
-       ao_telemetry_metrum_data_cur = cur;
+               ao_telemetry_metrum_data_max = (int16_t) (AO_SEC_TO_TICKS(1) / interval);
+               if (ao_telemetry_metrum_data_max > cur)
+                       cur++;
+               ao_telemetry_metrum_data_cur = cur;
 #endif
 
 #if HAS_COMPANION
-       if (!ao_companion_setup.update_period)
-               ao_companion_setup.update_period = AO_SEC_TO_TICKS(1);
-       ao_telemetry_companion_max = (int16_t) (ao_companion_setup.update_period / interval);
-       if (ao_telemetry_companion_max > cur)
-               cur++;
-       ao_telemetry_companion_cur = cur;
+               if (!ao_companion_setup.update_period)
+                       ao_companion_setup.update_period = AO_SEC_TO_TICKS(1);
+               ao_telemetry_companion_max = (int16_t) (ao_companion_setup.update_period / interval);
+               if (ao_telemetry_companion_max > cur)
+                       cur++;
+               ao_telemetry_companion_cur = cur;
 #endif
 
 #if HAS_GPS
-       ao_telemetry_gps_max = (int16_t) (AO_SEC_TO_TICKS(1) / interval);
-       if (ao_telemetry_gps_max > cur)
-               cur++;
-       ao_telemetry_loc_cur = cur;
-       if (ao_telemetry_gps_max > cur)
-               cur++;
-       ao_telemetry_sat_cur = cur;
-#endif
-
-       ao_telemetry_config_max = (int16_t) (AO_SEC_TO_TICKS(5) / interval);
-       if (ao_telemetry_config_max > cur)
-               cur++;
-       ao_telemetry_config_cur = cur;
+               ao_telemetry_gps_max = (int16_t) (AO_SEC_TO_TICKS(1) / interval);
+               if (ao_telemetry_gps_max > cur)
+                       cur++;
+               ao_telemetry_loc_cur = cur;
+               if (ao_telemetry_gps_max > cur)
+                       cur++;
+               ao_telemetry_sat_cur = cur;
+#endif
+
+               ao_telemetry_config_max = (int16_t) (AO_SEC_TO_TICKS(5) / interval);
+               if (ao_telemetry_config_max > cur)
+                       cur++;
+               ao_telemetry_config_cur = cur;
+       }
 
 #ifndef SIMPLIFY
        ao_telemetry_time =