[alsa-devel] [PATCH] ASoC: SOF: intel: Fix probe error without i915 graphics

[Kai Vehmanen]

Hey,

On Sun, 16 Feb 2020, Takashi Iwai wrote:

> @@ -200,6 +202,9 @@ int hda_codec_i915_exit(struct snd_sof_dev *sdev)
>  	struct hdac_bus *bus = sof_to_bus(sdev);
>  	int ret;
>  
> +	if (!bus->audio_component) /* not bound with i915 */
> +		return 0;
> +
>  	hda_codec_i915_display_power(sdev, false);
>  
>  	ret = snd_hdac_i915_exit(bus);

hmm, actually found the issue in my patch. It turned out to be a bit 
suprising issue with acomp&devres.

 snd_hdac_i915_exit() calls
   -> snd_hdac_acomp_exit(), which again calls
   -> component.c:component_master_del(dev, &hdac_component_master_ops);
   -> component.c:take_down_master()
   -> devres.c:devres_release_group(master->dev, NULL);

...  now that is somewhat suprising. Basicly that goes on to release all 
devres resources for the hdac_bus device (not just those related to 
acomp!).

I can fix my immediate problem by not calling snd_hdac_i915_exit() if 
hdac_bus contineus to be used, but I'm a bit worried we could hit this in 
other flows.

Anyways, FYI at least for the list archives.

Br, Kai