[PATCH 4.5 040/200] ALSA: hda - Keep powering up ADCs on Cirrus codecs

Greg Kroah-Hartman
2016-05-03T01:21:08Z

From: Takashi Iwai <tiwai@suse.de>

commit de3df8a986b635082a1d94bae2c361d043c57106 upstream.

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
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
sound/pci/hda/patch_cirrus.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

--- 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 h
{
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 h
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;
}