Re: [PATCH 1/2] ALSA: hda/hdmi: Add helper function to check if a device is HDMI codec

["Péter Ujfalusi" <peter.ujfalusi@linux.intel.com>]

On 27/11/2023 17:43, Takashi Iwai wrote:
> On Mon, 27 Nov 2023 16:40:57 +0100,
>>> --- a/include/sound/hdaudio.h
>>> +++ b/include/sound/hdaudio.h
>>> @@ -95,6 +95,7 @@ struct hdac_device {
>>>  	bool lazy_cache:1;	/* don't wake up for writes */
>>>  	bool caps_overwriting:1; /* caps overwrite being in process */
>>>  	bool cache_coef:1;	/* cache COEF read/write too */
>>> +	bool is_hdmi:1;		/* a HDMI/DP codec */
>>>  	unsigned int registered:1; /* codec was registered */
>>>  };
>>>  
>>> --- a/sound/pci/hda/patch_hdmi.c
>>> +++ b/sound/pci/hda/patch_hdmi.c
>>> @@ -2597,6 +2597,7 @@ static int patch_generic_hdmi(struct hda_codec *codec)
>>>  	}
>>>  
>>>  	generic_hdmi_init_per_pins(codec);
>>> +	codec->core.is_hdmi = true;
>>>  	return 0;
>>>  }
>>>  
>>> @@ -3472,6 +3473,7 @@ static int patch_simple_hdmi(struct hda_codec *codec,
>>>  	spec->pcm_playback = simple_pcm_playback;
>>>  
>>>  	codec->patch_ops = simple_hdmi_patch_ops;
>>> +	codec->core.is_hdmi = true;
>>>  
>>>  	return 0;
>>>  }
>>
>> I see,  so this is what I was not sure how to do ;)
>> I will rework the series and resend tomorrow.
>>
>> Thanks for the code snippet, I will make you as author of it, if it is
>> OK for you.
> 
> Sure, no problem.

The flag does not work with SOF stack which uses the hdac_hda codec driver:

patch_generic_hdmi() and patch_simple_hdmi() is not entered at all, so
the flag is not set.

The codec driver have is_hdmi_codec() helper to check the struct
hda_pcm.pcm_type, but that is not set early enough either.

The is HDMI or not needs to be known in hdac_hda_dev_probe(), I think
this was one of the reason I have opted to have the exported function.
We just don't have other information at the dev probe time.

# dmesg | grep peter
[    3.810841] [peter] hdac_hda_dev_probe: is_hdmi_codec(): 0
[    3.810846] [peter] hdac_hda_dev_probe: hdev->is_hdmi: 0
[    3.810848] [peter] hdac_hda_dev_probe: snd_hda_device_is_hdmi(): 0
...
[    3.814497] [peter] hdac_hda_dev_probe: is_hdmi_codec(): 0
[    3.814499] [peter] hdac_hda_dev_probe: hdev->is_hdmi: 0
[    3.814500] [peter] hdac_hda_dev_probe: snd_hda_device_is_hdmi(): 1
...
[    3.986610] [peter] generic_hdmi_build_pcms: ENTER
[    3.986627] [peter] hdac_hda_codec_probe: is_hdmi_codec(): 1
...
[    3.996383] [peter] snd_hda_parse_pin_defcfg: ENTER
[    4.001562] [peter] hdac_hda_codec_probe: is_hdmi_codec(): 0

-- 
Péter