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

Takashi Iwai
2023-11-27T15:43:43Z

On Mon, 27 Nov 2023 16:40:57 +0100,
Péter Ujfalusi wrote:
>
>
>
> On 27/11/2023 17:20, Takashi Iwai wrote:
> > On Mon, 27 Nov 2023 15:45:54 +0100,
> > Péter Ujfalusi wrote:
> >>
> >>
> >>
> >> On 27/11/2023 16:31, Takashi Iwai wrote:
> >>> On Mon, 27 Nov 2023 15:12:51 +0100,
> >>> Péter Ujfalusi wrote:
> >>>>
> >>>>
> >>>>
> >>>> On 27/11/2023 15:18, Takashi Iwai wrote:
> >>>>>> +bool snd_hda_device_is_hdmi(struct hdac_device *hdev)
> >>>>>> +{
> >>>>>> + int i;
> >>>>>> +
> >>>>>> + for (i = 0; i < ARRAY_SIZE(snd_hda_id_hdmi); i++) {
> >>>>>> + if (snd_hda_id_hdmi[i].vendor_id == hdev->vendor_id)
> >>>>>> + return true;
> >>>>>> + }
> >>>>>> +
> >>>>>> + return false;
> >>>>>> +}
> >>>>>> +EXPORT_SYMBOL_GPL(snd_hda_device_is_hdmi);
> >>>>>
> >>>>> I'm afraid that this will bring unnecessary dependency on HDMI codec
> >>>>> driver.
> >>>>
> >>>> For HDMI support we anyways need HDMI code?
> >>>
> >>> But the ASoC hdac-hda driver isn't specifically bound with HDMI, I
> >>> thought?
> >>>
> >>> With your patch, now it becomes a hard-dependency. It'll be even
> >>> build failure when HDMI codec driver isn't enabled in Kconfig.
> >>
> >> The change in hdaudio.h handles the config dependency, if
> >> CONFIG_SND_HDA_CODEC_HDMI is not enabled in Kconfig then
> >> snd_hda_device_is_hdmi() will return false.
> >
> > OK, that's at least good.
> > But I still find it not ideal to bring the hard dependency there
> > unnecessarily.
> >
> > With the introduction of a flag in hdac_device, the necessary change
> > would be even smaller like below.
> >
> >
> > Takashi
> >
> > --- 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.

Takashi