Currently the generic parser sets codec->power_filter when
power_save_node flag is set.  But this overrides the existing filter
that has been already set by the codec driver, thus it looses some
features.  Instead, set the default power_filter only when it's not
set yet.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
        parse_digital(codec);
 
        if (spec->power_down_unused || codec->power_save_node)
-               codec->power_filter = snd_hda_gen_path_power_filter;
+               if (!codec->power_filter)
+                       codec->power_filter = snd_hda_gen_path_power_filter;
 
        if (!spec->no_analog && spec->beep_nid) {
                err = snd_hda_attach_beep_device(codec, spec->beep_nid);