linux-kernel - Re: [PATCH 2/2] ALSA: hda/cs8409: Prevent pops and clicks during reboot

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Message-ID: <2974107a-787f-8788-2ee1-86b6c8055035@opensource.cirrus.com>
Date:   Thu, 26 Aug 2021 11:56:07 +0100
From:   Vitaly Rodionov <vitalyr@...nsource.cirrus.com>
To:     Takashi Iwai <tiwai@...e.de>
CC:     <alsa-devel@...a-project.org>, <patches@...nsource.cirrus.com>,
        Stefan Binding <sbinding@...nsource.cirrus.com>,
        Takashi Iwai <tiwai@...e.com>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/2] ALSA: hda/cs8409: Prevent pops and clicks during
 reboot

On 26/08/2021 11:49 am, Takashi Iwai wrote:
> On Thu, 26 Aug 2021 08:03:45 +0200,
> Takashi Iwai wrote:
>> On Wed, 25 Aug 2021 20:04:05 +0200,
>> Vitaly Rodionov wrote:
>>> Actually when codec is suspended and we do reboot from UI, then sometimes we
>>> see suspend() calls in kernel log and no pops, but sometimes
>>>
>>> we still have no suspend() on reboot and we hear pops. But when we do reboot
>>> from command line: > sudo reboot  then we always have pops and no suspend()
>>> called.
>>>
>>> Then we have added extra logging and we can see that on reboot codec somehow
>>> getting resume() call and we run jack detect on resume that causing pops.
>> Hm, it's interesting who triggers the runtime resume.
>>
>>> We were thinking about possible solution for that and we would propose some
>>> changes in generic code hda_bind.c:
>>>
>>> static void hda_codec_driver_shutdown(struct device *dev) { +   if (codec->
>>> patch_ops.suspend) +      codec->patch_ops.suspend(codec);
>>> snd_hda_codec_shutdown(dev_to_hda_codec(dev)); +  hda_codec_driver_remove
>>> (dev_to_hda_codec(dev)); }
>> Sorry, it's no-no.  The suspend can't be called unconditionally, and
>> the driver unbind must not be called in the callback itself.
>>
>> Does the patch below work instead?
> Sorry there was a typo.  A bit more revised patch is below.
>
>
> Takashi

Hi Takashi,

Thanks a lot for quick response. I have tested previous patch and it did 
not fix an issue, as suspend() was not called.

Now I will test new revised patch and let you know ASAP.

I am adding some extra logging, unfortunately on reboot these messages 
are missing from kernel log, however I managed to capture reboot screen

and I will attach an image where last messages shown.

Thanks,

Vitaly

>
> --- a/sound/pci/hda/hda_intel.c
> +++ b/sound/pci/hda/hda_intel.c
> @@ -1383,14 +1383,17 @@ static void azx_free(struct azx *chip)
>   	hda->freed = 1;
>   }
>   
> -static int azx_dev_disconnect(struct snd_device *device)
> +static void __azx_disconnect(struct azx *chip)
>   {
> -	struct azx *chip = device->device_data;
>   	struct hdac_bus *bus = azx_bus(chip);
>   
>   	chip->bus.shutdown = 1;
>   	cancel_work_sync(&bus->unsol_work);
> +}
>   
> +static int azx_dev_disconnect(struct snd_device *device)
> +{
> +	__azx_disconnect(device->device_data);
>   	return 0;
>   }
>   
> @@ -2356,8 +2359,10 @@ static void azx_shutdown(struct pci_dev *pci)
>   	if (!card)
>   		return;
>   	chip = card->private_data;
> -	if (chip && chip->running)
> +	if (chip && chip->running) {
> +		__azx_disconnect(chip);
>   		azx_shutdown_chip(chip);
> +	}
>   }
>   
>   /* PCI IDs */