[LAU] Fwd: Re: Raspberry Pi and real-time, low-latency audio

[Carlos sanchiavedraz]

2013/5/14 Jeremy Jongepier <jeremy at autostatic.com>:
>>> I've had the same issue. As you describe later you have to switch the USB
>>> controller to USB 1.1 mode and disable Advanced mode on the UA-25.
>>>
>>
>> Do you mean there is something to configure on RPi? If it is so I
>> think something did it. I didn't touched anything on RPi related to
>> USB, I just disabled Advanced mode on the UA25 turning off the switch
>> on the back, and I guess this is what cause the switching to 1.1. Is
>> it so?
>
>
> Hello Carlos,
>
> Not sure, I should try that out myself. Afaik disabling advanced mode is not
> enough, you should also add dwc_otg.speed=1 to your /boot/cmdline.txt file.
>

It's strange because that's what I did, disabling it in the UA. It was
messages like "USB 1.1 ..." when booting what led me to try switching
Advanced Mode to off in the UA25.
My cmdline.txt should be the same as Raspbian's although I made a
change to boot from usb stick.

    dwc_otg.lpm_enable=0 console=ttyAMA0,115200 kgdboc=ttyAMA0,115200
console=tty1 root=/dev/sda2 rootfstype=ext4 elevator=deadline rootwait

> [...]
>
>
>> As the mini SD 2G card was corrupted, I just use a 64MB for the boot
>> partition where I specify /dev/sda2 as the system partition. For the
>> moment it all went quite well. As I mentioned before, it runs RT
>> without a problem.
>>
>
> Have to give it another go then. Audio in my case was so glitchy that it was
> unusable actually.
>
>

I did nothing special, so it should go ok or perhaps there's some
issue in your case/with your usb stick.

>>> I'm using a powered hub with a 3.7A adapter which is more than enough. I
>>> bought this hub for €3, wouldn't call that expensive ;)
>>>
>>
>> That's really cheap. I have to find something similar to avoid more
>> power issues.
>>
>
> I have good experiences with dx.com (DealExtreme):
> http://dx.com/s/usb%2bhub%2bac%2badapter.html?sort=Price
> The hub I'm using now:
> http://www.amazon.de/7-Port-gerichtet-leichteren-Zugang-Staubverschlu%C3%9F/dp/B006ZZMSB8
>
> Regards,
>
> Jeremy
>
> _______________________________________________
> Linux-audio-user mailing list
> Linux-audio-user at lists.linuxaudio.org
> http://lists.linuxaudio.org/listinfo/linux-audio-user

Regards,

-- 
Carlos sanchiavedraz
* Musix GNU+Linux
  http://www.musix.es