[alsa-devel] [PATCH 3/3] ALSA: hda - hdmi: Notify userspace when ELD control changes

[David Henningsson]

On 02/18/2013 03:41 PM, Takashi Iwai wrote:
> At Mon, 18 Feb 2013 14:11:13 +0100,
> David Henningsson wrote:
>>
>> Since ELD sometimes becomes available a while after we have detected
>> presence, we need to be able to listen for changes on the ELD control.
>>
>> Signed-off-by: David Henningsson <david.henningsson at canonical.com>
>> ---
>>   sound/pci/hda/patch_hdmi.c |   10 ++++++++++
>>   1 file changed, 10 insertions(+)
>>
>> diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
>> index 9236cdb..d3b1a93 100644
>> --- a/sound/pci/hda/patch_hdmi.c
>> +++ b/sound/pci/hda/patch_hdmi.c
>> @@ -74,6 +74,7 @@ struct hdmi_spec_per_pin {
>>
>>   	struct hda_codec *codec;
>>   	struct hdmi_eld sink_eld;
>> +	struct snd_kcontrol *eld_ctl;
>>   	struct delayed_work work;
>>   	int repoll_count;
>>   	bool non_pcm;
>> @@ -406,6 +407,7 @@ static int hdmi_create_eld_ctl(struct hda_codec *codec, int pin_idx,
>>   	if (err < 0)
>>   		return err;
>>
>> +	spec->pins[pin_idx].eld_ctl = kctl;
>>   	return 0;
>>   }
>>
>> @@ -1175,6 +1177,7 @@ static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll)
>>   	 */
>>   	int present = snd_hda_pin_sense(codec, pin_nid);
>>   	bool eld_valid = false;
>> +	bool old_eld_valid = eld->eld_valid;
>>
>>   	memset(eld, 0, offsetof(struct hdmi_eld, eld_buffer));
>>
>> @@ -1196,6 +1199,13 @@ static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll)
>>   					   msecs_to_jiffies(300));
>>   		}
>>   	}
>> +
>> +	if (eld->eld_valid != old_eld_valid && per_pin->eld_ctl) {
>> +		snd_ctl_notify(codec->bus->card,
>> +			       SNDRV_CTL_EVENT_MASK_VALUE | SNDRV_CTL_EVENT_MASK_INFO,
>> +			       &per_pin->eld_ctl->id);
>> +	}
>
> This notification should be skipped when the pin sensing is requeued.

I don't understand this comment. Are you referring to repolling the ELD? 
eld->eld_valid is never set to TRUE when repoll happens.



-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic