[Discuss-gnuradio] usb errors while stopping flowgraph

[Brett L. Trotter]

I'm sure this has been asked many times, but if you would be so kind as
to offer any hints where to look for solutions or what to test, it would
be much appreciated.

I've got several different flowgraphs here that upon shutting down some
portion of the time, they emit a series of errors and then totally tank
my USB controller on a number of test systems, requiring a full system
reboot to reset the USB (the RHEL6 box I'm using has USB modules
compiled into the kernel, so rmmod isn't an option). The flowgraphs stop
normally about 3/4 times. It seems to be chance when its in some odd
state that it won't shutdown right.

Relevant code:
    tb = top_block()
    tb.start()
    raw_input("Press Enter to quit: \n")
    tb.stop()
    tb.wait()


Errors emitted:
usb_control_msg failed: error sending control message: Connection timed out
write_cmd failed
usrp_basic_tx: set_tx_enable(false) failed
usb_control_msg failed: error sending control message: Connection timed out
write_cmd failed
usrp_basic_rx: set_fpga_rx_enable failed
usb_control_msg failed: error sending control message: Connection timed out
write_cmd failed
usb_control_msg failed: error sending control message: Connection timed out
write_cmd failed
usrp_basic_rx: failed to fini AD9862 RX regs
usb_control_msg failed: error sending control message: Connection timed out
write_cmd failed
usb_control_msg failed: error sending control message: Connection timed out
write_cmd failed
usb_control_msg failed: error sending control message: Connection timed out
write_cmd failed
usb_control_msg failed: error sending control message: Connection timed out
write_cmd failed
usrp_basic_tx: failed to fini AD9862 TX regs