----- Mail original ----- > De: "alexander" <axeldenstore@xxxxxxxxx> > À: linux-audio-user@xxxxxxxxxxxxxxxxxxxx > Envoyé: Lundi 7 Janvier 2013 18:27:42 > Objet: Re: Sound Devices USBPre2, UAC2 status > I also own this interface, recently it has started to work in uac2 > mode, > I still cant raise the samplerate, but it runs.. however, It still > runs > alot better in uac1.. when in uac2 jack mysteriously shuts down for > no > appearant reason. I run archlinux, allways uptodated with vanilla > kernel. > > This is when I connect it without pressing 1. eg, uac2 > http://pastebin.com/BFJTwXnJ > And as with pressing 1. http://pastebin.com/ZJ1jbPUK Hi, In my understanding, you are not in UAC2 , you are in high-speed mode but the usb audio protocol remains UAC1. In the kernel source in the file include/uapi/linux/usb/audio.h is defined two values: /* bInterfaceProtocol values to denote the version of the standard used */ #define UAC_VERSION_1 0x00 #define UAC_VERSION_2 0x20 So if the card is in UAC2 , you should see bInterfaceProtocol at 32 (or 0x20) By example, now the RME babyface is recognize as UAC2 device, you can view its "lsub -v" here : http://minilien.fr/a0m3kc But for the usbPre2 device with ou without pressing the "1" button, we have bInterfaceProtocol = 0. So we stays in UAC1, even the speed increase to high-speed. So IMHO, it's why, we are already limited to 48khz framerate. If a usb audio guru can confirm my idea... I have no problem in high speed since kernel 3.2. Ubuntu kernel or vanilla kernel are OK (today, I use a 3.7.1 vanilla kernel). _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
