From: tianyu tianyu@kylinos.cn

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)