I'm following the advice of Matt Ettus in GR CON 19 to reduce the overall latency of my transmitter using BladeRF. No matter what max tags in flight and tagging interval I use, the flow graph would run for some time and then stop.
For troubleshooting, I printed the messages coming out from the "Tags to Message" block. I can see the "latency_strobe" tags printed during the initialization of the bladeRF. However, once the bladeRF starts transmitting (sync_tx starts working), the flow stops.
Any idea what the problem could be?
Below is my flowgraph
and below are the consol message:
[bladeRF sink] start: DEBUG: starting sink
[VERBOSE @ host/libraries/libbladeRF/src/backend/usb/nios_access.c:429] nios_config_read: Read 0x00000801
[VERBOSE @ host/libraries/libbladeRF/src/backend/usb/nios_access.c:440] nios_config_write: Wrote 0x00000801
[VERBOSE @ host/libraries/libbladeRF/src/board/bladerf2/common.c:343] check_total_sample_rate: active_channels=1, rate_accum=2000000, maximum=80000000
******* MESSAGE DEBUG PRINT ********
((({latency_strobe} . {0})))
************************************
******* MESSAGE DEBUG PRINT ********
((({latency_strobe} . {800})))
************************************
******* MESSAGE DEBUG PRINT ********
((({latency_strobe} . {1600})))
************************************
******* MESSAGE DEBUG PRINT ********
((({latency_strobe} . {2400})))
************************************
******* MESSAGE DEBUG PRINT ********
((({latency_strobe} . {3200})))
************************************
******* MESSAGE DEBUG PRINT ********
((({latency_strobe} . {4000})))
************************************
******* MESSAGE DEBUG PRINT ********
((({latency_strobe} . {4800})))
************************************
******* MESSAGE DEBUG PRINT ********
((({latency_strobe} . {5600})))
************************************
******* MESSAGE DEBUG PRINT ********
((({latency_strobe} . {6400})))
************************************
******* MESSAGE DEBUG PRINT ********
((({latency_strobe} . {7200})))
************************************
[DEBUG @ host/libraries/libbladeRF/src/streaming/sync.c:1001] sync_tx: Worker is now running.
[DEBUG @ host/libraries/libbladeRF/src/backend/usb/libusb.c:1426] Non-blocking buffer submission requested, but no transfers are currently available.
** Note: the last message saying "non-blocking buffer submission requested" would always appear. If I remove the latency manager, that message would appear and the workflow would run normally.
Ahmad Oweis