Re: [alsa-devel] [PATCH] hda: STAC927x power down inactive DACs

30 Jan 2008

Takashi Iwai wrote:
...
At Wed, 30 Jan 2008 09:14:02 -0500,
Matthew Ranostay wrote:
...
On several laptops that have STAC9228 codecs have unused DACs, this powers them down to a D3 state.
Signed-off-by: Matthew Ranostay mranostay@embeddedalley.com
I think they will be eventually powered up again in
hda_set_power_state() in hda_codec.c.  As a temporary solution, we can
have a sort of blacklist in struct hda_codec for always turning the
power off for such widgets.
As a long-term solution, the automatic detection of such widgets would
be nice...
Takashi
...

diff -r 86c8c0a82bb9 pci/hda/patch_sigmatel.c

--- a/pci/hda/patch_sigmatel.c	Wed Jan 30 11:52:33 2008 +0100
+++ b/pci/hda/patch_sigmatel.c	Wed Jan 30 08:58:37 2008 -0500
@@ -288,6 +288,10 @@ static hda_nid_t stac927x_adc_nids[3] =
static hda_nid_t stac927x_mux_nids[3] = {
         0x15, 0x16, 0x17
+};



+static hda_nid_t stac927x_dac_nids[5] = {

0x02, 0x03, 0x04, 0x05, 0x06

};
static hda_nid_t stac927x_dmux_nids[1] = {
@@ -3537,7 +3541,7 @@ static int patch_stac927x(struct hda_cod
 static int patch_stac927x(struct hda_codec *codec)
 {
   struct sigmatel_spec *spec;

int err;


int err, i;
spec  = kzalloc(sizeof(*spec), GFP_KERNEL);
if (spec == NULL)


@@ -3628,6 +3632,14 @@ static int patch_stac927x(struct hda_cod
   	stac92xx_free(codec);
   	return err;
   }


/* on some 3-stack systems not all the DACs are used

* this powers down ones that aren't used


*/


for (i = 0; i < ARRAY_SIZE(stac927x_dac_nids); i++)

if (!is_in_dac_nids(spec, stac927x_dac_nids[i]))


	snd_hda_codec_write_cache(codec, stac927x_dac_nids[i],


		0, AC_VERB_SET_POWER_STATE, AC_PWRST_D3);


codec->patch_ops = stac92xx_patch_ops;


I think this what you had in mind.
Also is putting the function call in stac92xx_resume correct?
diff -r 86c8c0a82bb9 pci/hda/patch_sigmatel.c
--- a/pci/hda/patch_sigmatel.c	Wed Jan 30 11:52:33 2008 +0100
+++ b/pci/hda/patch_sigmatel.c	Wed Jan 30 16:52:00 2008 -0500
@@ -135,6 +135,7 @@ struct sigmatel_spec {
    /* power management */
    unsigned int num_pwrs;
    hda_nid_t *pwr_nids;
+	hda_nid_t *dac_list;
/* playback */
    struct hda_input_mux *mono_mux;
@@ -288,6 +289,10 @@ static hda_nid_t stac927x_adc_nids[3] =
static hda_nid_t stac927x_mux_nids[3] = {
         0x15, 0x16, 0x17
+};
+
+static hda_nid_t stac927x_dac_nids[6] = {
+	0x02, 0x03, 0x04, 0x05, 0x06, 0
 };
static hda_nid_t stac927x_dmux_nids[1] = {
@@ -2858,6 +2863,18 @@ static int is_nid_hp_pin(struct auto_pin
    return 0; /* nid is not a HP-Out */
 };
+static void stac92xx_power_down(struct hda_codec *codec)
+{
+	struct sigmatel_spec *spec = codec->spec;
+
+	/* power down inactive DACs */
+	hda_nid_t *dac;
+	for (dac = spec->dac_list; *dac; dac++)
+		if (!is_in_dac_nids(spec, *dac))
+			snd_hda_codec_write_cache(codec, *dac, 0,
+					AC_VERB_SET_POWER_STATE, AC_PWRST_D3);
+}
+
 static int stac92xx_init(struct hda_codec *codec)
 {
    struct sigmatel_spec *spec = codec->spec;
@@ -2910,7 +2927,8 @@ static int stac92xx_init(struct hda_code
    	enable_pin_detect(codec, spec->pwr_nids[i], event | i);
    	codec->patch_ops.unsol_event(codec, (event | i) << 26);
    }
-
+	if (spec->dac_list)
+		stac92xx_power_down(codec);
    if (cfg->dig_out_pin)
    	stac92xx_auto_set_pinctl(codec, cfg->dig_out_pin,
    				 AC_PINCTL_OUT_EN);
@@ -3083,6 +3101,9 @@ static int stac92xx_resume(struct hda_co
    	spec->gpio_dir, spec->gpio_data);
    snd_hda_codec_resume_amp(codec);
    snd_hda_codec_resume_cache(codec);
+	/* power down inactive DACs */
+	if (spec->dac_list)
+		stac92xx_power_down(codec);
    /* invoke unsolicited event to reset the HP state */
    if (spec->hp_detect)
    	codec->patch_ops.unsol_event(codec, STAC_HP_EVENT << 26);
@@ -3569,6 +3590,7 @@ static int patch_stac927x(struct hda_cod
    spec->num_adcs = ARRAY_SIZE(stac927x_adc_nids);
    spec->mux_nids = stac927x_mux_nids;
    spec->num_muxes = ARRAY_SIZE(stac927x_mux_nids);
+	spec->dac_list = stac927x_dac_nids;
    spec->multiout.dac_nids = spec->dac_nids;
switch (spec->board_config) {

    