I'm using an Airspy HF+ Discovery with the Soapy driver. Whenever I turn AGC off it stops receiving samples.

On closer inspection, switching AGC off results in samples stalling for
an extended period (hundreds of milliseconds). As such, we hit the
timeout in SoapyAirspyHF::readStream() and return SOAPY_SDR_TIMEOUT
(-1).

Things go wrong at this point. It takes a long time before readStream()
is called again, presumably because we returned 0 from work(). By this
time our buffers have overflown, readStream() returns SOAPY_SDR_OVERFLOW
(-2) and work() returns 0. We loop forever, continually overflowing
buffers.

Fix this by looping in soapy_source_c::work() when ->readStream returns
SOAPY_SDR_OVERFLOW so that we consume the buffers straight away.

Signed-off-by: Anton Blanchard <anton at ozlabs.org>

Signed-off-by: Eric Wild <ewild@sysmocom.de>
This commit is contained in:
Anton Blanchard 2020-08-02 23:50:43 +02:00 committed by Eric Wild
parent 137c568c60
commit 49f9b2df2a
1 changed files with 8 additions and 3 deletions

View File

@ -96,9 +96,14 @@ int soapy_source_c::work( int noutput_items,
{ {
int flags = 0; int flags = 0;
long long timeNs = 0; long long timeNs = 0;
int ret = _device->readStream( int ret;
_stream, &output_items[0], int retries = 1;
noutput_items, flags, timeNs);
do {
ret = _device->readStream(
_stream, &output_items[0],
noutput_items, flags, timeNs);
} while (retries-- && (ret == SOAPY_SDR_OVERFLOW));
if (ret < 0) return 0; //call again if (ret < 0) return 0; //call again
return ret; return ret;