Comment 28 for bug 1884940

The only way to get sound back is to : remove power. turn off laptop
Wait a few minutes until sound card is totally off and resets itself to its standard state
And boot laptop again

Something in the kernel is putting the intel sound card in a state that prevents it from working again on next reboot or wake up until the machine is turned off and power source removed

This was not occuring on previous kernels.