FHSS WS: Do not use drift compensation with unpredictable linux timer (ARMmbed#2418)

Jarkko Paso · web-flow · commit 01a1909c9479 · 2020-08-19T12:52:57.000+03:00
diff --git a/source/Service_Libs/fhss/fhss_ws.c b/source/Service_Libs/fhss/fhss_ws.c
@@ -993,7 +993,10 @@ int fhss_ws_set_parent(fhss_structure_t *fhss_structure, const uint8_t eui64[8],
             } else if (drift_per_ms_tmp < -MAX_DRIFT_COMPENSATION_STEP) {
                 drift_per_ms_tmp = -MAX_DRIFT_COMPENSATION_STEP;
             }
+            // Timer drift is unpredictable with linux platform. Do not set drift compensation
+#ifndef __linux__
             fhss_structure->ws->drift_per_millisecond_ns += drift_per_ms_tmp;
+#endif
             fhss_stats_update(fhss_structure, STATS_FHSS_DRIFT_COMP, NS_TO_US((int64_t)(fhss_structure->ws->drift_per_millisecond_ns * bc_timing_info->broadcast_dwell_interval)));
         }
         tr_debug("synch to parent: %s, drift: %"PRIi32"ms in %"PRIu64" seconds, compensation: %"PRIi32"ns per ms", trace_array(eui64, 8), true_bc_interval_offset - own_bc_interval_offset + ((int32_t)(fhss_structure->ws->bc_slot - own_bc_slot) * bc_timing_info->broadcast_interval), US_TO_S(time_since_last_synch_us), fhss_structure->ws->drift_per_millisecond_ns);

Original file line number	Diff line number	Diff line change
`@@ -993,7 +993,10 @@ int fhss_ws_set_parent(fhss_structure_t *fhss_structure, const uint8_t eui64[8],`
`993`	`993`	`} else if (drift_per_ms_tmp < -MAX_DRIFT_COMPENSATION_STEP) {`
`994`	`994`	`drift_per_ms_tmp = -MAX_DRIFT_COMPENSATION_STEP;`
`995`	`995`	`}`
	`996`	`+ // Timer drift is unpredictable with linux platform. Do not set drift compensation`
	`997`	`+#ifndef __linux__`
`996`	`998`	`fhss_structure->ws->drift_per_millisecond_ns += drift_per_ms_tmp;`
	`999`	`+#endif`
`997`	`1000`	`fhss_stats_update(fhss_structure, STATS_FHSS_DRIFT_COMP, NS_TO_US((int64_t)(fhss_structure->ws->drift_per_millisecond_ns * bc_timing_info->broadcast_dwell_interval)));`
`998`	`1001`	`}`
`999`	`1002`	`tr_debug("synch to parent: %s, drift: %"PRIi32"ms in %"PRIu64" seconds, compensation: %"PRIi32"ns per ms", trace_array(eui64, 8), true_bc_interval_offset - own_bc_interval_offset + ((int32_t)(fhss_structure->ws->bc_slot - own_bc_slot) * bc_timing_info->broadcast_interval), US_TO_S(time_since_last_synch_us), fhss_structure->ws->drift_per_millisecond_ns);`