I got my Dell XPS 13 9343 with preinstalled windows 8. Later I added ubuntu 15.04 in dual boot mode. Everytime I booted into windows and came back to ubuntu later, the sound will go missing, but I could recover it by rebooting twice into ubuntu.

Recently I upgraded windows to Windows 10. Now I am unable to recover sound in ubuntu in spite of repeated rebooting into ubuntu.

Can someone please help?

thanks