On Thu, Nov 24, 2011 at 9:04 AM, Stefan Hajnoczi <stefa...@gmail.com> wrote: > On Wed, Nov 23, 2011 at 4:01 PM, Gerd Hoffmann <kra...@redhat.com> wrote: >> For starter try a higher number of buffers (isobufs property). >> Also make sure you enable the vnc thread (unless you have already).
Tested with vnc thread and isobufs=32. This time the stderr output is: USBDEVFS_SUBMITURB: File too large [several times, followed by...] husb: out of buffers for iso stream [many times] I can still ping the guest and issue QEMU monitor commands while the display and audio appear to be frozen. Moving the mouse makes it the audio responsive again. Next I disabled USB tablet in case there is an interaction between USB passthrough and the emulated tablet. The audio still gets stuck but moving the mouse no longer helps. So the mouse is just a distraction, iso buffers are simply not working and USB table emulation somehow "kicks" guest USB back into action. Then I tested playback and capture separately in case it was specific to just one data direction, but both playback and capture freeze in the same way. (Playback means the guest is handing filled out iso buffers to the device. Capture means the guest is asking the device to fill in iso buffers.) Any suggestions where to go from here? Stefan