Mirror/betaflight
1
0
Fork 0
mirror of https://github.com/betaflight/betaflight.git synced 2025-07-24 16:55:36 +03:00
Code Issues Wiki Activity

Revise data structures for DSHOT telemetry stats to avoid high CPU load

Browse source 
Having the stats data structures incorporated into the `dmaMotors[]` array structure was causing excessive CPU load on F4. The actual cause is unknown, but likely some kind of negative cache interaction. Moving the stats to a standalone array separate from `dmaMotors[]` solves the problem.
This commit is contained in:
Bruce Luckcuck 2019-05-04 14:40:06 -04:00
parent de1c1d5377
commit 0b420d5a49
2 changed files with 19 additions and 22 deletions
Download patch file Download diff file Expand all files Collapse all files

22
src/main/drivers/pwm_output_dshot_shared.c
View file

@ -46,6 +46,22 @@
#include "pwm_output_dshot_shared.h"
#ifdef USE_DSHOT_TELEMETRY_STATS
#define DSHOT_TELEMETRY_QUALITY_WINDOW 1 // capture a rolling 1 second of packet stats
#define DSHOT_TELEMETRY_QUALITY_BUCKET_MS 100 // determines the granularity of the stats and the overall number of rolling buckets
#define DSHOT_TELEMETRY_QUALITY_BUCKET_COUNT (DSHOT_TELEMETRY_QUALITY_WINDOW * 1000 / DSHOT_TELEMETRY_QUALITY_BUCKET_MS)
typedef struct dshotTelemetryQuality_s {
uint32_t packetCountSum;
uint32_t invalidCountSum;
uint32_t packetCountArray[DSHOT_TELEMETRY_QUALITY_BUCKET_COUNT];
uint32_t invalidCountArray[DSHOT_TELEMETRY_QUALITY_BUCKET_COUNT];
uint8_t lastBucketIndex;
} dshotTelemetryQuality_t;
static FAST_RAM_ZERO_INIT dshotTelemetryQuality_t dshotTelemetryQuality[MAX_SUPPORTED_MOTORS];
#endif // USE_DSHOT_TELEMETRY_STATS
FAST_RAM_ZERO_INIT uint8_t dmaMotorTimerCount = 0;
#ifdef STM32F7
FAST_RAM_ZERO_INIT motorDmaTimer_t dmaMotorTimers[MAX_DMA_TIMERS];
@ -265,7 +281,7 @@ bool pwmStartDshotMotorUpdate(uint8_t motorCount)
}
dmaMotors[i].hasTelemetry = false;
#ifdef USE_DSHOT_TELEMETRY_STATS
updateDshotTelemetryQuality(&dmaMotors[i].dshotTelemetryQuality, validTelemetryPacket, currentTimeMs);
updateDshotTelemetryQuality(&dshotTelemetryQuality[i], validTelemetryPacket, currentTimeMs);
#endif
} else {
timeDelta_t usSinceInput = cmpTimeUs(micros(), dmaMotors[i].timer->inputDirectionStampUs);
@ -295,8 +311,8 @@ int16_t getDshotTelemetryMotorInvalidPercent(uint8_t motorIndex)
int16_t invalidPercent = 0;
if (dmaMotors[motorIndex].dshotTelemetryActive) {
const uint32_t totalCount = dmaMotors[motorIndex].dshotTelemetryQuality.packetCountSum;
const uint32_t invalidCount = dmaMotors[motorIndex].dshotTelemetryQuality.invalidCountSum;
const uint32_t totalCount = dshotTelemetryQuality[motorIndex].packetCountSum;
const uint32_t invalidCount = dshotTelemetryQuality[motorIndex].invalidCountSum;
if (totalCount > 0) {
invalidPercent = lrintf(invalidCount * 10000.0f / totalCount);
}