[Patch] Intel-hda sound card emulation problem

    This patch fixed an intel-hda sound card emulation problem as follows:

    http://lists.gnu.org/archive/html/qemu-devel/2013-01/msg05453.html

    I found a bug that qemu doesn't support for setting master volume/mute when guest is winxp. but the wave volume in the volume control works fine.I don't know why it does.

    And then the reporter submitted the patch, but not accepted by qemu mainline.

    http://lists.gnu.org/archive/html/qemu-devel/2013-01/msg05452.html
[Patch] Lower uhci timer freq when guest is idle.

UHCI emulation polls the device at a freq of 1000HZ, which consumes
25-30% CPU even though a Windows guest is completely idle.

This solution counts accumulated NAK packets. when it reaches to 64,
then the guest is supposed to be idle and the freq is lowered to 10HZ.

This patch has been tested on Win7/WinXP/F17 guests.