S2D_TELEMETRY_BYTES_MAX
fsize = min(num_samples, S2D_TELEMETRY_BYTES_MAX);
if (num_samples > S2D_TELEMETRY_BYTES_MAX) {
stb_rdptr_offset = num_samples % S2D_TELEMETRY_BYTES_MAX;
fsize = S2D_TELEMETRY_BYTES_MAX - stb_rdptr_offset;
if (size != S2D_TELEMETRY_BYTES_MAX)