From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: assigned EHCI USB headset not working Date: Thu, 09 Jun 2011 17:24:32 +0200 Message-ID: <4DF0E5B0.8030704@siemens.com> References: <4DEF17C1.7000805@web.de> <4DEF6FC9.8040209@redhat.com> <4DF065E9.4070605@web.de> <4DF06DED.7030604@web.de> <4DF07182.3060003@web.de> <4DF07218.7000903@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: =?ISO-8859-1?Q?Andr=E9_Weidemann?= , Gerd Hoffmann , "kvm@vger.kernel.org" , qemu-devel To: malc Return-path: Received: from thoth.sbs.de ([192.35.17.2]:28631 "EHLO thoth.sbs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752525Ab1FIPYp (ORCPT ); Thu, 9 Jun 2011 11:24:45 -0400 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On 2011-06-09 17:13, malc wrote: > On Thu, 9 Jun 2011, Jan Kiszka wrote: > >> On 2011-06-09 09:08, Andr? Weidemann wrote: >>> Hi Jan, >>> >>> On 09.06.2011 08:53, Jan Kiszka wrote: >>>> On 2011-06-09 08:19, Andr? Weidemann wrote: >>>>> Hi Gerd, >>>>> >>>>> On 08.06.2011 14:49, Gerd Hoffmann wrote: >>>>>> Hi, >>>>>> >>>>>>> The sound device shows up under Windows7 and drivers are installed >>>>>>> automatically. Unfortunately it does not work. All the players I >>>>>>> tried, >>>>>>> did not even start playing the sound file, although they detected the >>>>>>> DirectSound Device. >>>>>> >>>>>> iso xfer's from usb-linux via ehci are flaky for reasons not yet >>>>>> tracked >>>>>> down. >>>>>> >>>>>> Any reason why you don't just plug in a virtual sound card? The HDA >>>>>> emulation should work fine with win7. >>>>> >>>>> Using the hda driver was my first attempt. But the result was not very >>>>> convincing. When playing mp3s inside the VM, I could hear music coming >>>>> from the speakers, but the sound was very choppy and too slow. It was no >>>>> joy listening to it. >>>> >>>> Does "export QEMU_AUDIO_DAC_TRY_POLL=0" before invoking qemu helps? It >>>> depends on your host-side interface. Using ALSA here, it is generally >>>> required. >>>> >>>> Note that this discussion rather belongs on qemu-devel. >>> >>> Thank you very much. Setting the variable did the trick. >>> Could this perhaps be included in the man page? I am sure there will be >>> others who will eventually run into the same problem as I did. >> >> It is a long-standing issue of QEMU that I always wanted to understand >> but never found the time for. CC'ing malc, maybe he has a good idea how >> to finally attack this. >> > > Attack what exactly? Sound output over (at least) ALSA is not smoothly working in polled mode. It's similar to [1], which is yet unsolved. Jan [1] http://thread.gmane.org/gmane.comp.emulators.qemu/52365 -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux