[PD] raspberry pi user experience

[Miller Puckette]

I heard suggestions on the Pi sites (I forget exactly where) that the USB
2.0 implementation isn't compatible with a large variety of USB 2.0 devices
(including for instance the Griffin iMic).  So I don't think the issue is
the load that USB 2.0 puts on the Pi, it's simply bugs.  But I gather nobody
is in a hurry to get them fixed - the attitude in Cambridge is that it's the
devices' fault, not the Pi's.

I have beem suspecting that my keyboard is also incompatible with the Pi at
USB 1.1 speed.  I haven't tried other keyboards yet since I'm usually happy
to ssh in without any other USB devices (besides audio and ethernet)
talking to the Pi.  But this is not always true so soon enough I'll have to
try other keyboards so I can get the thing working as a standalone computer.

cheers
Miller

On Sun, Jan 27, 2013 at 04:50:16PM +0100, katja wrote:
> Thanks Pierre and Cyrille.
> 
> It turned out that various keyboards and mouse just kill USB (when at
> 1.1) on the Pi. 'Keysonic Wireless Trackball Keyboard' happens to work
> well. The lower USB speed brings substantial improvement of the audio
> indeed. Now a real realtime kernel, that would probably improve things
> further.
> 
> Katja
> 
> 
> 
> On Sun, Jan 27, 2013 at 2:33 PM, Cyrille Henry <ch at chnry.net> wrote:
> > i put it in front of everything :
> >
> > dwc_otg.speed=1 dwc_otg.lpm_enable=0 console=ttyAMA0,115200
> > kgdboc=ttyAMA0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4
> > elevator=deadline rootwait
> >
> > cheers
> > c
> >
> > Le 27/01/2013 11:42, katja a écrit :
> >
> >> Hello,
> >>
> >> Some people seem to have result with setting lower USB speed on the
> >> Pi, but when I try this, the Pi doesn't even respond to keyboard
> >> anymore. Checking /boot/cmdline.txt with another computer, I'm sure it
> >> is not due to a typo. But the order of settings may be important?
> >> Could anyone copy the full text of /boot/cmdline.txt for me, if you
> >> have keyboard working with lowered USB speed? (I'm not talking about
> >> good audio yet).
> >>
> >> Thanks,
> >> Katja
> >>
> >>
> >> On Sat, Jan 26, 2013 at 8:54 PM, Thomas Grill <gr at grrrr.org> wrote:
> >>>
> >>> Message to self: it seems that one has to wait for updated RPi USB
> >>> firmware/drivers to get USB 2.0 audio going.
> >>> Obviously the "isochronous transfer mode" as used by audio interfaces is
> >>> currently broken.
> >>> gr~~~
> >>>
> >>>
> >>> 2013/1/26 Thomas Grill <gr at grrrr.org>
> >>>>
> >>>>
> >>>> Hi all,
> >>>> for my USB audio class 2.0 device "Native Instruments Komplete Audio 6"
> >>>> i
> >>>> can't report such good news.
> >>>> There is constant irregular crackling, not only with Pd but also with
> >>>> aplay etc. It seems related to USB bandwidth, since turning on and off
> >>>> the
> >>>> inputs in Pd changes crackling frequency. The dwc_otg.speed setting is
> >>>> not
> >>>> usable for me, since the device is dependent on USB 2.0 operation.
> >>>> Any experiences with USB 2.0 audio devices under ALSA/rpi?
> >>>> thanks,
> >>>> gr~~~
> >>>>
> >>>>
> >>>> 2013/1/26 Cyrille Henry <ch at chnry.net>
> >>>>>
> >>>>>
> >>>>> hello,
> >>>>>
> >>>>> I just install raspbian release and update it. then install pd 0.44.1
> >>>>> (without any specific optimisation flag)
> >>>>>
> >>>>> I made the standard optimisation :
> >>>>> * - rtprio 99
> >>>>> * - memlock 1000000000
> >>>>> in /etc/security/limits.conf
> >>>>>
> >>>>> and
> >>>>> dwc_otg.speed=1
> >>>>> in /boot/cmdline.txt
> >>>>> as suggested by miller
> >>>>>
> >>>>> I use a uca222 beringher (that cost about 20 or 25€) sound card.
> >>>>> trying the test audio and midi, there is no click with 10ms audio
> >>>>> buffer
> >>>>> (with adc~ enable).
> >>>>>
> >>>>> this is with usb keyboard / mouse combo plugged and graphical interface
> >>>>> (for the system and for pd).
> >>>>>
> >>>>> without X, audiobuf can be as low as 5ms
> >>>>>
> >>>>> having a usb keyboard did not change anything for me.
> >>>>>
> >>>>> i'm very happy
> >>>>>
> >>>>> cheers
> >>>>> c
> >>>>>
> >>>>> _______________________________________________
> >>>>> Pd-list at iem.at mailing list
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> >>>>> http://lists.puredata.info/listinfo/pd-list
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>> --
> >>>> Thomas Grill
> >>>> http://grrrr.org
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> --
> >>> Thomas Grill
> >>> http://grrrr.org
> >>>
> >>> _______________________________________________
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> >>>
> >>
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> >
> 
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