Sound works after a cold boot but not after a reboot from windows.
This patch will solve this issue. This is relation with Class-D power control.

[ The bug was reported in Bugzilla below for Sony VAIO SVS13A1C5E
  -- tiwai]

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=197737
Cc: <stable@vger.kernel.org>
Signed-off-by: Kailang Yang <kailang@realtek.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>