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sdr: properly flush the transmit buffers

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This commit is contained in:
Thomas Kolb 2024-01-03 00:25:55 +01:00
parent 497498acd2
commit 628659511c
3 changed files with 17 additions and 8 deletions
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5
impl/src/main.c
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@ -264,16 +264,13 @@ int main(void)
if(!on_air) {
RESULT_CHECK(sdr_stop_rx(&sdr));
RESULT_CHECK(sdr_start_tx(&sdr, burst_len * SDR_OVERSAMPLING));
// hopefully no longer needed with latest libhackrf
//RESULT_CHECK(sdr_flush_tx_buffer(&sdr));
}
RESULT_CHECK(transmit_in_chunks(&sdr, whole_burst, burst_len));
on_air = true;
} else if(on_air) { // ret == 0
//RESULT_CHECK(sdr_flush_tx_buffer(&sdr));
RESULT_CHECK(sdr_flush_tx_buffer(&sdr));
RESULT_CHECK(sdr_stop_tx(&sdr));
RESULT_CHECK(sdr_start_rx(&sdr));

18
impl/src/sdr/sdr.c
View file

@ -67,6 +67,7 @@ static inline int8_t clamp_float2int8(float s)
static int tx_callback(hackrf_transfer *transfer)
{
int result;
int retcode = 0;
sdr_ctx_t *sdr_ctx = (sdr_ctx_t*)transfer->tx_ctx;
@ -86,9 +87,15 @@ static int tx_callback(hackrf_transfer *transfer)
result = cbuffercf_read(sdr_ctx->tx_buf, samples_requested, &samples, &samples_read);
if(result != LIQUID_OK) {
fprintf(stderr, "cbuffercf_read failed: %d. Samples are lost.\n", result);
sem_post(&sdr_ctx->buf_sem);
return HACKRF_ERROR_OTHER;
}
if(samples_read == 0) {
// buffer has run empty, so this is the end of the transmission
sdr_ctx->tx_done = true;
}
for(size_t i = 0; i < samples_read; i++) {
transfer->buffer[2*i + 0] = clamp_float2int8(creal(samples[i]));
transfer->buffer[2*i + 1] = clamp_float2int8(cimag(samples[i]));
@ -111,7 +118,7 @@ static int tx_callback(hackrf_transfer *transfer)
return HACKRF_ERROR_OTHER;
}
return 0;
return retcode;
}
static result_t stop_streaming(sdr_ctx_t *ctx)
@ -282,12 +289,13 @@ result_t sdr_transmit(sdr_ctx_t *ctx, const float complex *samples, size_t nsamp
return ERR_LIQUID;
}
ctx->tx_done = false;
if(sem_post(&ctx->buf_sem) < 0) {
perror("sem_post");
return ERR_SDR;
}
return OK;
}
@ -334,8 +342,10 @@ result_t sdr_receive(sdr_ctx_t *ctx, float complex *samples, size_t *nsamples, l
result_t sdr_flush_tx_buffer(sdr_ctx_t *ctx)
{
// currently not implemented
(void)ctx;
while(!ctx->tx_done) {
struct timespec ts_1ms = {0, 1000000};
nanosleep(&ts_1ms, NULL);
}
return OK;
}

2
impl/src/sdr/sdr.h
View file

@ -3,6 +3,7 @@
#include <complex.h>
#include <semaphore.h>
#include <stdbool.h>
#include <libhackrf/hackrf.h>
@ -30,6 +31,7 @@ typedef struct {
sem_t buf_sem;
sdr_status_t status;
bool tx_done;
} sdr_ctx_t;
result_t sdr_init(sdr_ctx_t *ctx);