[Hackrf-dev] And I can't make work 2 hackrf boards in GRC

[Dominic Spill]

On 3 March 2016 at 01:45, Leandro Leoncini <leoncini at gmail.com> wrote:
>   Hi, I can't make work 2 hackrf at the same time in GRC. Both devices work
> well one at the time but not at the same time. When both are connected I can
> see them in hackrf_info:
>
> hackrf_info
> Found HackRF board 0:
> USB descriptor string: 0000000000000000321864c83940521d
> Board ID Number: 2 (HackRF One)
> Firmware Version: 2015.07.2
> Part ID Number: 0xa000cb3c 0x00624735
> Serial Number: 0x00000000 0x00000000 0x321864c8 0x3940521d
>
> Found HackRF board 1:
> USB descriptor string: 000000000000000014d463dc2f8e9ce1
> Board ID Number: 2 (HackRF One)
> Firmware Version: 2015.07.2
> Part ID Number: 0xa000cb3c 0x0068475a
> Serial Number: 0x00000000 0x00000000 0x14d463dc 0x2f8e9ce1
>
>
>   But when I start using one of them in GRC this is what I get:
>
> hackrf_info
> Found HackRF board 0:
> USB descriptor string: 0000000000000000321864c83940521d
> hackrf_open() failed: HACKRF_ERROR_LIBUSB (-1000)

This doesn't look like the kernel's SDR driver because it at least
works once.  Assuming you're running HackRF tools 2015.07.2 (and the
fact that you're seeing serial numbers in the hackrf_info output
suggests you are), libHackRF will be unloading the kernel driver for
you.

>   I'm on Linux Mint 17.3 with GRC 3.7.9.1 so any idea of what can be the
> problem?

This looks a lot like a power management issue to me.  The USB stack
on HackRF doesn't yet support suspend mode, which wasn't a problem
until distros recently started using it.

The short term fix for this is to blacklist the device from power
saving.  If you have a file called /etc/default/tlp on your system,
add the following line:
USB_BLACKLIST="1d50:6089 1d50:604b 1d50:cc15 1d50:60e6"

If Mint is using laptop-mode instead, you'll find a directory called
/etc/laptop-mode/conf.d/ in to which you should place a file called
hackrf.conf with the following:
AUTOSUSPEND_USBID_BLACKLIST="1d50:604b"
AUTOSUSPEND_USBID_BLACKLIST="1d50:cc15"
AUTOSUSPEND_USBID_BLACKLIST="1d50:6089"

Let me know if this solves the problem for you.  I hope to find a way
to fix this more permanently in future.

Dominic