[PATCH v6 2/2] ASoC: SOF: Fix deadlock when shutdown a frozen userspace

[Pierre-Louis Bossart]

On 11/30/22 09:47, Ricardo Ribalda wrote:
> During kexec(), the userspace is frozen. Therefore we cannot wait for it
> to complete.
> 
> Avoid running snd_sof_machine_unregister during shutdown.

That's not what you are doing below - you only unregister clients
conditionally.

I don't know if that's a stale commit message and can't reconcile it
either with the initial discussions in this thread where we were
referring to snd_card_disconnect(), etc?

Confused.

> @@ -484,7 +485,8 @@ int snd_sof_device_shutdown(struct device *dev)
>  	 * make sure clients and machine driver(s) are unregistered to force
>  	 * all userspace devices to be closed prior to the DSP shutdown sequence
>  	 */
> -	sof_unregister_clients(sdev);
> +	if (!kexec_with_frozen_processes())
> +		sof_unregister_clients(sdev);
>  
>  	snd_sof_machine_unregister(sdev, pdata);
>  
>