ALSA: hda - Keep powering up ADCs on Cirrus codecs

Although one weird behavior about the input path (inconsistent D0/D3
switch) on Cirrus CS420x codecs was fixed in the previous commit,
there is still an issue on some Mac machines: the capture stream
stalls when switching the ADCs on the fly.  More badly, this keeps
stuck until the next reboot.

The dynamic ADC switching is already a bit fragile and assuming
optimistically that the chip accepts the frequent power changes.  On
Cirrus codecs, this doesn't seem applicable.

As a quick workaround, we pin down the ADCs to keep up in D0 when
spec->dyn_adc_switch is set.  In this way, the ADCs are kept up only
for the system that were confirmed to be broken.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=116171
Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/pci/hda/patch_cirrus.c b/sound/pci/hda/patch_cirrus.c
index a47e8ae..80bbadc 100644 (file)
--- a/sound/pci/hda/patch_cirrus.c
+++ b/sound/pci/hda/patch_cirrus.c
@@ -361,6 +361,7 @@ static int cs_parse_auto_config(struct hda_codec *codec)
 {
        struct cs_spec *spec = codec->spec;
        int err;
+       int i;
 
        err = snd_hda_parse_pin_defcfg(codec, &spec->gen.autocfg, NULL, 0);
        if (err < 0)
@@ -370,6 +371,19 @@ static int cs_parse_auto_config(struct hda_codec *codec)
        if (err < 0)
                return err;
 
+       /* keep the ADCs powered up when it's dynamically switchable */
+       if (spec->gen.dyn_adc_switch) {
+               unsigned int done = 0;
+               for (i = 0; i < spec->gen.input_mux.num_items; i++) {
+                       int idx = spec->gen.dyn_adc_idx[i];
+                       if (done & (1 << idx))
+                               continue;
+                       snd_hda_gen_fix_pin_power(codec,
+                                                 spec->gen.adc_nids[idx]);
+                       done |= 1 << idx;
+               }
+       }
+
        return 0;
 }