On Tue, 23 Nov 2021 09:07:14 +0100,
tianyucode wrote:
>
> 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.
For VIA codecs, there is an additional fixup table to turn off the
power_save_node. Add an entry with the PCI SSID of your device to
vt2002p_fixups[] table with VIA_FIXUP_POWER_SAVE.
thanks,
Takashi
