At Fri, 13 Mar 2009 11:47:35 +0100, Giovanni Maruzzelli wrote: > > Dear Takashi, > > please can you help me getting this issue started? I would like to go > in deep and help solve this issue. > > Would you please tell me how to be useful? (which kind of info to > gather, which people-mailing list to write to, etc.) Isn't it really a bandwidth overflow? I know it worked, but it doesn't mean that it did right. Anyway this issue is more related with the usb-driver rather than the sound driver. I recommend you to ask / discuss on linux-usb ML. Takashi > Thanks in advance, > Giovanni > > On Wed, Mar 11, 2009 at 8:08 PM, Giovanni Maruzzelli > <gmaruzz.lists@xxxxxxxxx> wrote: > > Dear ALSA developers, > > > > my application needs to use multiple USB soundcards (based on standard > > cm-108 chipset) for I/O. > > > > Seems to me that with recent kernels (after 2.6.21) this is almost impossible: > > > > -if you use uhci_hcd it crashes with 4 running soundcards (cannot > > submit datapipe: not enough bandwidth) > > -if you use ehci_hcd it crashes way before (device resets) > > > > With older kernels, at least uhci_hcd seems to work. This maybe is > > related to the reworking of the bandwidth management into the uhci_hcd > > introduced in 2.6.21. > > > > I'm available to and I would be glad to help you ALSA developers with > > all the information possible: just tell me wich infos you need and > > I'll gather all the infos for you. > > > > You can test the problem with: > > arecord -Dplughw:0 | aplay plughw:0 & > > arecord -Dplughw:1 | aplay plughw:1 & > > arecord -Dplughw:2 | aplay plughw:2 & > > arecord -Dplughw:3 | aplay plughw:3 & > > > _______________________________________________ > Alsa-devel mailing list > Alsa-devel@xxxxxxxxxxxxxxxx > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel > _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
