I was working on my project (pi4b, amp4) last night with no sound issues.
This morning I plug it in and attempt to play music as I was yesterday with no sound playing.
Checking journalctl while attempting to play music I see it being flooded by these errors being spammed:
Jun 04 18:54:34 * kernel: pcm512x 1-004d: ASoC: error at snd_soc_pcm_component_pm_runtime_get on pcm512x.1-004d: -22
Jun 04 18:54:34 * kernel: HiFiBerry DAC+: ASoC: error at __soc_pcm_open on HiFiBerry DAC+: -22
Jun 04 18:54:34 * kernel: pcm512x 1-004d: ASoC: error at snd_soc_pcm_component_pm_runtime_get on pcm512x.1-004d: -22
Jun 04 18:54:34 * kernel: HiFiBerry DAC+: ASoC: error at __soc_pcm_open on HiFiBerry DAC+: -22
Doing a quick search I find this rpi kernel GitHub issue which looks like it's the same problem (https://github.com/raspberrypi/linux/issues/5763)
Seeing that it's closed and seemed to have a fix in a newer kernel update, I attempt to update with rpi-update, and it succeeds.
Checking journalctl again after updating (sound is still not working) I only see one error being repeated and then some more info once I stop playback:
Jun 04 20:23:04 * kernel: pcm512x 1-004d: ASoC: error at snd_soc_pcm_component_pm_runtime_get on pcm512x.1-004d: -22
... (repeats for a while)
Jun 04 20:23:02 * kernel: pcm512x 1-004d: ASoC: error at snd_soc_pcm_component_pm_runtime_get on pcm512x.1-004d: -22
Jun 04 20:23:00 * kernel: HiFiBerry DAC+: ASoC: error at __soc_pcm_open on HiFiBerry DAC+: -110
Jun 04 20:23:00 * kernel: pcm512x 1-004d: ASoC: error at snd_soc_pcm_component_pm_runtime_get on pcm512x.1-004d: -110
Jun 04 20:23:00 * kernel: pcm512x 1-004d: Failed to remove power down: -110
Thanks to anyone who helps, this has been driving me nuts all day
