are you using latest alsa driver since
http://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/?id=eb33ccf7637c34b2c95dbcca8b2e4cab76a52949
https://wiki.ubuntu.com/Audio/UpgradingAlsa/DKMS
are you using latest alsa driver since
http:// git.kernel. org/cgit/ linux/kernel/ git/tiwai/ sound.git/ commit/ ?id=eb33ccf7637 c34b2c95dbcca8b 2e4cab76a52949
https:/ /wiki.ubuntu. com/Audio/ UpgradingAlsa/ DKMS