On 22.04.2013 21:23, Torstein Hegge wrote: > On Mon, Apr 22, 2013 at 20:44:40 +0200, Daniel Mack wrote: >> Also, the lsusb dumps don't contain a audio specific header descriptor, >> which normally looks like this: >> >> AudioControl Endpoint Descriptor: >> bLength 7 >> bDescriptorType 37 >> bDescriptorSubtype 1 (EP_GENERAL) >> bmAttributes 0x01 >> Sampling Frequency >> bLockDelayUnits 0 Undefined >> wLockDelay 0 Undefined >> >> And without the "Sampling Frequency" bit in bmAttributes, the driver >> will bail out early (clock.c): > > I think it has the class specific endpoint descriptor, but it is in > front of the standard endpoint descriptor. From the 'lsusb -v': > > AudioStreaming Interface Descriptor: > bLength 14 > bDescriptorType 36 > bDescriptorSubtype 2 (FORMAT_TYPE) > bFormatType 1 (FORMAT_TYPE_I) > bNrChannels 2 > bSubframeSize 2 > bBitResolution 16 > bSamFreqType 2 Discrete > tSamFreq[ 0] 16000 > tSamFreq[ 1] 48000 > ** UNRECOGNIZED: 07 25 01 81 02 00 00 > Endpoint Descriptor: > bLength 9 > bDescriptorType 5 > bEndpointAddress 0x03 EP 3 OUT > bmAttributes 1 > Transfer Type Isochronous > Synch Type None > Usage Type Data > wMaxPacketSize 0x00c0 1x 192 bytes > bInterval 1 > bRefresh 0 > bSynchAddress 0 > > The UNRECOGNIZED bit matches the missing AudioControl endpoint > descriptor.
Ah, yes, good catch. > Even if this is against the specification, devices that does this is out > there. I have seen the same thing on a Sennheiser BTD-500, but that only > supports one frequency, so I didn't hit this problem. Yes, if that's the case, we should patch both lsusb and the snd-usb driver. Let's see who provides a patch first :) Daniel ------------------------------------------------------------------------------ Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis & visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter _______________________________________________ Alsa-user mailing list Alsa-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user
