[alsa-devel] [PATCH v3 04/10] ASoC: SOF: Intel: add support for snd-hda-codec-hdmi

[Pierre-Louis Bossart]

On 9/12/19 7:06 AM, Kai Vehmanen wrote:
> Hey,
> 
> On Tue, 10 Sep 2019, Pierre-Louis Bossart wrote:
>>> --- a/sound/soc/sof/intel/hda-codec.c
>>> +++ b/sound/soc/sof/intel/hda-codec.c
>>> @@ -84,6 +84,8 @@ static int hda_codec_probe(struct snd_sof_dev *sdev, int
> [...]
>>> +	/*
>>> +	 * if common HDMI codec driver is not used, codec load
>>> +	 * is skipped here and hdac_hdmi is used instead
>>> +	 */
>>> +	if ((mach_params && mach_params->common_hdmi_codec_drv) ||
>>> +	    (resp & 0xFFFF0000) != IDISP_VID_INTEL) {
>>>    		hdev->type = HDA_DEV_LEGACY;
>>>    		hda_codec_load_module(&hda_priv->codec);
>>
>> This part is might be problematic. For SoundWire stuff, I had to move all the
>> machine detection part out of hda_init_caps() and at the end of hda_dsp_probe.
>> It's not final since I am still trying to figure out what the earliest time I
>> can power-up the SoundWire IP is, but it would help if you don't make strong
>> assumptions on when mach_params is set. The fact that all this code is
>> currently in hda_init_caps() is not really by design, more because of
>> incremental code changes.
> 
> hmm. Currently the settings part of 'common_hdmi_codec_drv' is in in
> init_caps, just before call to hda_codec_probe_bus() (which uses the
> flag). There are also other fields set there (like
> mach_params->codec_mask), so issues should apply to codec_mask passing as
> well. I.e. if functionality is moved out from init_caps, the call to bus
> probe should be moved as well.
> 
> Other options to pass the flag do not seem good. We don't want to add hw
> specific stuff like this to snd_sof_dev or hdac_bus (latter used to pass
> "codec_mask"). If this becomes an issue, maybe we just need an explicit
> parameter to hda_codec_probe_bus(), and/or move the module parameter
> directly to intel/hda-codec.c. Both are a bit ugly, but at least contained
> in the "sof/intel/" subfolder.

never mind, with the SoundWire plumbing rework we can do all the machine 
driver checks in hda_init_caps. I split the ACPI scan, driver probe and 
startup in 3 steps so we have more freedom. Before this rework I was 
constrained to detect the ACPI stuff only when the hardware was powered, 
which was after init_caps.
In short don't worry about me/SoundWire.