> On Nov 13, 2015, at 11:56 AM, Steve French <[email protected]> wrote:
> 
> Erik,
> Let me preface this by saying that I feel your pain and I dont understand how 
> to fix the problem.  It might be something software related that someone will 
> help us with or it might be a fundamental flaw in the BBB usb hardware.  I am 
> not sure.  My below input is intended to help add some more light in the 
> search for an answer...
> 
> I and other people have wasted several days troubleshooting the same thing 
> that you are referring to.  There is something wrong with the BBB USB 
> handling that is maddening.  Here are a few things I have discovered on the 
> subject:
> 
> 1) The BBB has problems using my generic USB midi device (works 0% of the 
> time), but the Raspberry Pi and Ubuntu Laptop can use it without problems 
> (works 100% of the time).

Can you try the 4.1 kernel?

> 
> 2) I have found that things do show up in both systems using the "lsusb" 
> command....BUT for some reason something goes wrong during the USB 
> enumeration process on the BBB.  If you look at the output of "dmesg" you can 
> see some strange descriptor errors that happen during the BBB enumeration 
> process. 

Can you share?

> As a result, when you do "aconnect -i" or "aconnect -o" or "aconnect -l" on 
> the rPi you can see that the proper endpoints have been setup....but on the 
> BBB that does not happen.
> 
> root@rPiB1:~# aconnect -i
> client 0: 'System' [type=kernel]
>     0 'Timer           '
>     1 'Announce        '
> client 14: 'Midi Through' [type=kernel]
>     0 'Midi Through Port-0'
> client 20: 'USB2.0-MIDI' [type=kernel]
>     0 'USB2.0-MIDI MIDI 1'
> client 128: 'qlcplus' [type=user]
>     0 '__QLC__         '
> root@rPiB1:~# aconnect -o
> client 14: 'Midi Through' [type=kernel]
>     0 'Midi Through Port-0'
> client 20: 'USB2.0-MIDI' [type=kernel]
>     0 'USB2.0-MIDI MIDI 1'
>     1 'USB2.0-MIDI MIDI 2'
> client 128: 'qlcplus' [type=user]
>     0 '__QLC__         '
> 
> 
> On my Ubuntu laptop:
> frenchy@frenchy-HP-2000-Notebook-PC:~$ aconnect -l
> client 0: 'System' [type=kernel]
>     0 'Timer           '
>     1 'Announce        '
> client 14: 'Midi Through' [type=kernel]
>     0 'Midi Through Port-0'
> client 20: 'USB2.0-MIDI' [type=kernel]
>     0 'USB2.0-MIDI MIDI 1'
>     1 'USB2.0-MIDI MIDI 2'
> client 128: 'qlcplus' [type=user]
>     0 '__QLC__         '
> 
> 
> 
> On the BBB:
> I never grabbed the output for my notes (whoops), but the endpoints werent 
> there.
> 
> 
> Here are the notes that I wrote to myself a few days ago when I was 
> researching this:
> -Regarding the BBB, I think I wasted a whole day on the same problem about 
> 1or2 years ago when it came to those cheap $4 Bluetooth adapters from 
> China....the "lsusb" command saw the device (same as today with the USB midi 
> device.)...but then dmesg started throwing strange descriptor errors during 
> the 2nd phase of USB enumeration....as a result, the device is never really 
> registered properly with the kernel level software modules like bluez in the 
> bluetooth case or alsa's aconnect in today's case.
> 
> -What a freaking waste of time caused by the BBB for me and other 
> people!!!!!!!!

The 3.8 kernel doesn't use DMA. That usually isn't an issue, but could be for 
some devices. 

> 
> -Two years ago with the Bluetooth problem I deduced that it is caused by 
> cheap chinese («««<$) devices which skimp on the Vbus bulk bypass 
> capacitance.  For whatever reason rPis and Laptops dont seem to have a 
> problem!!  But the BBB consistently crashes because of a Vbus dip during USB 
> enumeration....the crash happens when the device is supposed to be sending 
> some descriptors over...so it is never recognized properly...and therefore 
> never fully functional nor available to the linux system. [Not sure if an 
> unstable Vbus is really the problem...it was just a theory I was wondering 
> about.]
> 
> 
> Here is another guy who came to perhaps similar conclusions:
> https://autostatic.com/2013/09/17/exit-beaglebone-black-hello-cubieboard2/

Let's find a fix. If I can replicate, maybe some capacitance can be shown to 
fix the issue. 

> 
> Good Luck and let me know if you find anything that leads to the USB midi 
> device working on the BBB.  I have not been able to get it working yet.  
> Right now I have reached the sad conclusion that if I want to use my USB midi 
> device, then I have to use the rPi instead of the BBB.  Interestingly, I am 
> able to use cheap USB soundcards (audio only) with the BBB all the time 
> without problem (per my 7part tutorial here).
> 
> respect,
> frenchy (Steve French)
> www.voltvision.com
> 
> 
> 
>> On Tuesday, November 10, 2015 at 5:02:41 PM UTC-5, [email protected] 
>> wrote:
>> 
>> Hi!
>> 
>> I've been trying to solve this problem all day and now I'm all out of ideas. 
>> I have a BeagleBone Black rev C and I'm running SuperCollider on it for a 
>> live performance thing. The problem arises when I try to connect a midi 
>> controller to it (the Korg nanoKONTROL2). On my desktop computer (Ubuntu 
>> Studio) it works plug & play, but on the BBB SuperCollider can't find it at 
>> all and SC gets its midi in/out from ALSA so it must be that ALSA can't find 
>> it for some reason. 
>> 
>> "lsusb" shows it and "cat /dev/midi1" gives me live output from it. It even 
>> shows up in "cat /proc/asound/cards". The USB sound card on the same USB hub 
>> works like a charm.
>> 
>> lsmod gives me
>> 
>> Module                  Size  Used by
>> snd_seq                46038  1 
>> snd_seq_device          5895  1 snd_seq
>> g_ether                23958  0 
>> libcomposite           15028  1 g_ether
>> snd_usb_audio         100405  3 
>> snd_hwdep               4885  1 snd_usb_audio
>> snd_usbmidi_lib        15375  1 snd_usb_audio
>> omap_rng                4062  0 
>> mt7601Usta            458758  0 
>> 
>> which seems like it might be some module missing. Originally I used an old 
>> BBB debian version, but I have now upgraded with a fresh flash of the eMMC 
>> and recompiled jack2 and SuperCollider without any luck. What should I do?
>> 
>> Cheers,
>> 
>> Erik Natanael Gustafsson
> 
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