Re: [PATCH] ASoC: hdmi-codec: register hpd callback on component probe

[Jerome Brunet]

On Fri 15 Dec 2023 at 14:55, Hsin-Yi Wang <hsinyi@xxxxxxxxxx> wrote:

> On Fri, Dec 15, 2023 at 12:40 AM Jerome Brunet <jbrunet@xxxxxxxxxxxx> wrote:
>>
>>
>> On Fri 15 Dec 2023 at 12:51, Zhengqiao Xia
>> <xiazhengqiao@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>>
>> > Hi Jerome,
>> >
>> > After my testing, I found that this patch will cause the audio on the external display to not work properly after
>> > restart.
>> > You move the plugged_cb to run in hdmi_probe, at this time hcp- > jack = NULL, the driver cannot report `SND_JACK_LINEOUT
>> > ` normally.
>> > static void hdmi_codec_jack_report(struct hdmi_codec_priv *hcp,
>> >                                  unsigned int jack_status)
>> > {
>> >       printk("xzq-866 hdmi_codec_jack_report: jack=%x, jack_status=%d", hcp->jack, jack_status != hcp->jack_status);
>> >       if (hcp->jack && jack_status != hcp->jack_status) {
>> >               snd_soc_jack_report(hcp->jack, jack_status, SND_JACK_LINEOUT);
>> >               hcp->jack_status = jack_status;
>> >       }
>> > }
>> > So we must call  plugged_cb  in hdmi_codec_set_jack,  Can you make some changes?
>>
>> Hi Zhengqiao,
>>
>> That is unfortunate. Sorry.
>>
>> This patch has changed when the hpd callback is registered, no when it
>> comes in effect. This is still dependent on calling .set_jack() and it
>> is not happening any later than it was before. So, in theory, it should
>> not have changed anything, if your driver actually relies on the HPD
>> event.
>>
>> Trying to guess what is happening for you, I suppose your HDMI driver is
>> "faking" an HPD event to report the initial jack status when the
>> hook_plugged_cb() is called. Could you point me to the hdmi driver you
>> are using so I can have a look ?
>>
>> My reference when testing this was dw-hdmi-i2s-audio and it does not do
>> that, it just registers the callback. I think this is what it supposed
>> to do TBH.
>>
>> An idea I have been thinking about for a while is have the hdmi-codec
>> insert the jack in the card itself, instead of the card doing. That
>> would give the jack "for free" to any user of the HDMI codec and might
>> also solve your issue. It would require a small rework of the cards doing
>> the hdmi jack register, but there are not many of these AFAIK.
>>
>
> The driver is it6505. The implementation of hook_plugged_cb():
> 1. register plugged_cb
> 2. call plugged_cb(bool plugged)
>
> bridge detect callback it6505_detect would also call plugged_cb, but
> only on the first time hpd status changed (eg. changed from connect
> <--> disconnect)
> it6505_detect() {
>   status = it6505->hpd_state ...
>   ...
>   if (it6505->connector_status != status) {
>     it6505->connector_status = status;
>     it6505_plugged_status_to_codec(it6505); // this will call plugged_cb
>   }
> }
>
> Unfortunately the first time after boot that hpd status changed was
> detected before set_jack. If we replug hdmi, the plugged_cb() was
> called by bridge_detect, which is expected.
>
> Prior to this patch, the initial plugged_cb() was called by hook_plugged_cb().
> After the patch, plugged_cb() should be called by hpd change (by
> bridge detect), but due to the driver logic only calling it on the
> first hpd state change, it fails to call plugged_cb() again when jack
> is set.

This is what thought 

>
> I checked the dw-hdmi.c's bridge_detect, and it's similar in that it
> also checks the last_connector_result, so maybe it's due to a timing
> difference?

No, I have overlooked that.
I'm preparing a fix. I'll Cc you.

Eventually, I still would like to make it easier for cards to use the
HDMI jack and have to codec do that registration on its own. It will
require some rework of cards already doing it.

I've only seen 2 cards doing that at the moment:
* imx-hdmi.c
* mt8188-mt6359.c

Could you point me to yours ?

>
>> >
>> > On Mon, Nov 6, 2023 at 6:40 PM Jerome Brunet <jbrunet@xxxxxxxxxxxx> wrote:
>> >
>> >  The HDMI hotplug callback to the hdmi-codec is currently registered when
>> >  jack is set.
>> >
>> >  The hotplug not only serves to report the ASoC jack state but also to get
>> >  the ELD. It should be registered when the component probes instead, so it
>> >  does not depend on the card driver registering a jack for the HDMI to
>> >  properly report the ELD.
>> >
>> >  Fixes: 25ce4f2b3593 ("ASoC: hdmi-codec: Get ELD in before reporting plugged event")
>> >  Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
>> >  ---
>> >   sound/soc/codecs/hdmi-codec.c | 27 +++++++++++++++++++--------
>> >   1 file changed, 19 insertions(+), 8 deletions(-)
>> >
>> >  diff --git a/sound/soc/codecs/hdmi-codec.c b/sound/soc/codecs/hdmi-codec.c
>> >  index 09eef6042aad..20da1eaa4f1c 100644
>> >  --- a/sound/soc/codecs/hdmi-codec.c
>> >  +++ b/sound/soc/codecs/hdmi-codec.c
>> >  @@ -877,18 +877,13 @@ static int hdmi_codec_set_jack(struct snd_soc_component *component,
>> >                                 void *data)
>> >   {
>> >          struct hdmi_codec_priv *hcp = snd_soc_component_get_drvdata(component);
>> >  -       int ret = -ENOTSUPP;
>> >
>> >          if (hcp->hcd.ops->hook_plugged_cb) {
>> >                  hcp->jack = jack;
>> >  -               ret = hcp->hcd.ops->hook_plugged_cb(component->dev->parent,
>> >  -                                                   hcp->hcd.data,
>> >  -                                                   plugged_cb,
>> >  -                                                   component->dev);
>> >  -               if (ret)
>> >  -                       hcp->jack = NULL;
>> >  +               return 0;
>> >          }
>> >  -       return ret;
>> >  +
>> >  +       return -ENOTSUPP;
>> >   }
>> >
>> >   static int hdmi_dai_spdif_probe(struct snd_soc_dai *dai)
>> >  @@ -982,6 +977,21 @@ static int hdmi_of_xlate_dai_id(struct snd_soc_component *component,
>> >          return ret;
>> >   }
>> >
>> >  +static int hdmi_probe(struct snd_soc_component *component)
>> >  +{
>> >  +       struct hdmi_codec_priv *hcp = snd_soc_component_get_drvdata(component);
>> >  +       int ret = 0;
>> >  +
>> >  +       if (hcp->hcd.ops->hook_plugged_cb) {
>> >  +               ret = hcp->hcd.ops->hook_plugged_cb(component->dev->parent,
>> >  +                                                   hcp->hcd.data,
>> >  +                                                   plugged_cb,
>> >  +                                                   component->dev);
>> >  +       }
>> >  +
>> >  +       return ret;
>> >  +}
>> >  +
>> >   static void hdmi_remove(struct snd_soc_component *component)
>> >   {
>> >          struct hdmi_codec_priv *hcp = snd_soc_component_get_drvdata(component);
>> >  @@ -992,6 +1002,7 @@ static void hdmi_remove(struct snd_soc_component *component)
>> >   }
>> >
>> >   static const struct snd_soc_component_driver hdmi_driver = {
>> >  +       .probe                  = hdmi_probe,
>> >          .remove                 = hdmi_remove,
>> >          .dapm_widgets           = hdmi_widgets,
>> >          .num_dapm_widgets       = ARRAY_SIZE(hdmi_widgets),
>>
>>
>> --
>> Jerome


-- 
Jerome