It is ALSA bug #1754.
 D6 bit in 02 register is PW4.
Signed-off-by: NAlexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJaroslav Kysela <perex@perex.cz>