From: tianyu <tianyu@xxxxxxxxxx>
Hi guys, I'm a new guy for audio driver.
I have encountered a problem. When using the VT1802 codec,
there will be no sound occasionally. After checking the initialization process,
I found that the cause of the problem is that the power state does not have
hda_set_power_state(codec, AC_PWRST_D0).
1. The power state is set to AC_PWRST_D0 during the first initialization：
azx_probe_continue
azx_probe_codecs
snd_hda_codec_new
snd_hda_codec_device_new
hda_set_power_state(codec, AC_PWRST_D0);
2. Then, the power state is set to AC_PWRST_D3 in VT1802, but not set in realtek (ALC269).
azx_probe_continue
azx_codec_configure
…
patch_vt2002
via_parse_auto_config
snd_hda_gen_parse_auto_config
add_all_pin_power_ctls
add_pin_power_ctls
set_path_power
static void add_all_pin_power_ctls(struct hda_codec *codec, bool on)
{
/**/
if (!codec->power_save_node)
return;
add_pin_power_ctls(codec, cfg->line_outs, cfg->line_out_pins, on);
/**/
}
The power_save_node is set to 0 in patch_alc269 and it returns here,
but it is set to 1 in VT1802.
patch_vt2002P
via_new_spec
codec->power_save_node = 1;
via_parse_auto_config
snd_hda_gen_parse_auto_config
codec->power_save_node = 0;//it set to 0 here,but add_all_pin_power_ctls has been done
patch_alc269
codec->power_save_node = 0;
3. Next there is a suspend and resume process, the resume process will also set the
power state to AC_PWRST_D0, but I think there is a problem with this process.
(1)suspend:
azx_probe_continue
snd_card_register
..
snd_hda_codec_dev_register
snd_hda_codec_register
snd_hda_power_down
pm_runtime_put_autosuspend
__pm_runtime_suspend(dev, RPM_GET_PUT | RPM_ASYNC | RPM_AUTO);
rpm_suspend
static int rpm_suspend(struct device *dev, int rpmflags)
{
/**/
if (rpmflags & RPM_ASYNC) {
dev->power.request = (rpmflags & RPM_AUTO) ?
RPM_REQ_AUTOSUSPEND : RPM_REQ_SUSPEND;
if (!dev->power.request_pending) {
dev->power.request_pending = true;
queue_work(pm_wq, &dev->power.work);
}
goto out;
}
__update_runtime_status(dev, RPM_SUSPENDING);
/**/
retval = rpm_callback(callback, dev);
__update_runtime_status(dev, RPM_SUSPENDED);
/**/
}
The first call to rpm_suspend has the RPM_ASYNC flag, so queue_work is called,
and the work queue is used to enter rpm_suspend
pm_runtime_init
INIT_WORK(&dev->power.work, pm_runtime_work);
(2)resume:
azx_probe_continue
set_default_power_save
snd_hda_set_power_save(&chip->bus, val * 1000);
codec_set_power_save(c, delay);
int val = power_save;
static int power_save = CONFIG_SND_HDA_POWER_SAVE_DEFAULT;//It is 0 in my .config
static void codec_set_power_save(struct hda_codec *codec, int delay)
{
struct device *dev = hda_codec_dev(codec);
if (delay == 0 && codec->auto_runtime_pm)
delay = 3000;
if (delay > 0) {
pm_runtime_set_autosuspend_delay(dev, delay);
pm_runtime_use_autosuspend(dev);
pm_runtime_allow(dev);
if (!pm_runtime_suspended(dev))
pm_runtime_mark_last_busy(dev);
} else {
pm_runtime_dont_use_autosuspend(dev);
pm_runtime_forbid(dev);
}
}
pm_runtime_forbid
rpm_resume(dev, 0);
static int rpm_resume(struct device *dev, int rpmflags)
{
/**/
if (dev->power.runtime_status == RPM_ACTIVE) {
retval = 1;
goto out;
}
/**/
_update_runtime_status(dev, RPM_RESUMING);
retval = rpm_callback(callback, dev);
/**/
__update_runtime_status(dev, RPM_ACTIVE);
/**/
}
The callback functions of suspend and resume are as follows, which set the power state:
hda_call_codec_suspend
state = hda_set_power_state(codec, AC_PWRST_D3);
hda_call_codec_resume
hda_set_power_state(codec, AC_PWRST_D0);
You can see that the resume function relies on dev->power.runtime_status,
and the status is set in rpm_suspend. The operation of rpm_suspend depends
on the scheduling of the work queue. I added print debugging on my machine,
and occasionally there will be pm_runtime_work in Run after rpm_resume.
At this time, the suspend and resume processes are not performed correctly.
In VT1802, the power_state is still D3, and the machine has no sound.
4. I searched the Internet and did not find the relevant modification,
but found the commit 317d9313925c (ALSA: hda/realtek-Set default power save node to 0).
Does VIA need to be modified like this?
Since I am not familiar with ALSA and runtime pm, so come here to consult.
---
sound/pci/hda/patch_via.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/patch_via.c b/sound/pci/hda/patch_via.c
index a29d7e989fe6..d01ea582cf25 100644
--- a/sound/pci/hda/patch_via.c
+++ b/sound/pci/hda/patch_via.c
@@ -1073,8 +1073,10 @@ static int patch_vt2002P(struct hda_codec *codec)
snd_hda_pick_fixup(codec, NULL, vt2002p_fixups, via_fixups);
snd_hda_apply_fixup(codec, HDA_FIXUP_ACT_PRE_PROBE);
- if (spec->codec_type == VT1802)
+ if (spec->codec_type == VT1802) {
+ codec->power_save_node = 0;
err = snd_hda_add_verbs(codec, vt1802_init_verbs);
+ }
else
err = snd_hda_add_verbs(codec, vt2002P_init_verbs);
if (err < 0)
--
2.25.1
