After a fresh reboot, the sound works ok but if I put the computer to sleep (pm-suspend), after it wakes up there is no sound anymore.

I did try 'alsa force-reload' after suspend but still no sound. After 'pm-hibernate' sound is back again.

I found an old thread here: https://bugzilla.kernel.org/show_bug.cgi?id=49421 where Michael seems to have the same problem which is still unsolved; maybe I can help with more info.

I attached the 'alsa-info.sh' output before and after suspend: 'alsa-info.txt.before' and 'alsa-info.txt.after'

The PC is here: http://www.dell.com/us/p/xps-27-2720-aio/pd?ref=PD_OC, but the 2y older version with no touch

If I boot into windows (8.1) everything works great, including sound (even after suspend)