Re: [PATCH] ALSA: hda/hdmi: Use 'AC_PINSENSE_ELDV' to detect pinsense for Loongson

[Takashi Iwai <tiwai@suse.de>]

On Tue, 26 May 2026 13:19:40 +0200,
Huacai Chen wrote:
> 
> Due to a hardware defect, for Loongson PCI HDMI devices with a reversion
> ID of 2, the pin sense status must be determined via the ELD.
> 
> Add a codec flag, eld_jack_detect, to indicate this case, and do special
> handlings in read_pin_sense().
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Baoqi Zhang <zhangbaoqi@loongson.cn>
> Signed-off-by: Haowei Zheng <zhenghaowei@loongson.cn>
> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
> ---
>  include/sound/hda_codec.h    | 1 +
>  sound/hda/codecs/hdmi/hdmi.c | 8 +++++++-
>  sound/hda/common/jack.c      | 4 ++++
>  3 files changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/include/sound/hda_codec.h b/include/sound/hda_codec.h
> index 24581080e26a..1a1fe7a904c3 100644
> --- a/include/sound/hda_codec.h
> +++ b/include/sound/hda_codec.h
> @@ -259,6 +259,7 @@ struct hda_codec {
>  	unsigned int forced_resume:1; /* forced resume for jack */
>  	unsigned int no_stream_clean_at_suspend:1; /* do not clean streams at suspend */
>  	unsigned int ctl_dev_id:1; /* old control element id build behaviour */
> +	unsigned int eld_jack_detect:1;	/* Machine jack-detection by ELD */
>  
>  	unsigned long power_on_acct;
>  	unsigned long power_off_acct;
> diff --git a/sound/hda/codecs/hdmi/hdmi.c b/sound/hda/codecs/hdmi/hdmi.c
> index f20d1715da62..423cd9f683c6 100644
> --- a/sound/hda/codecs/hdmi/hdmi.c
> +++ b/sound/hda/codecs/hdmi/hdmi.c
> @@ -2285,6 +2285,7 @@ EXPORT_SYMBOL_NS_GPL(snd_hda_hdmi_acomp_init, "SND_HDA_CODEC_HDMI");
>  enum {
>  	MODEL_GENERIC,
>  	MODEL_GF,
> +	MODEL_LOONGSON,
>  };
>  
>  static int generichdmi_probe(struct hda_codec *codec,
> @@ -2302,6 +2303,11 @@ static int generichdmi_probe(struct hda_codec *codec,
>  	if (id->driver_data == MODEL_GF)
>  		codec->no_sticky_stream = 1;
>  
> +	if (id->driver_data == MODEL_LOONGSON) {
> +		if (codec->bus && codec->bus->pci->revision == 0x2)
> +			codec->eld_jack_detect = 1; /* Jack-detection by ELD */
> +	}
> +
>  	return 0;
>  }
>  
> @@ -2319,7 +2325,7 @@ static const struct hda_codec_ops generichdmi_codec_ops = {
>  /*
>   */
>  static const struct hda_device_id snd_hda_id_generichdmi[] = {
> -	HDA_CODEC_ID_MODEL(0x00147a47, "Loongson HDMI",		MODEL_GENERIC),
> +	HDA_CODEC_ID_MODEL(0x00147a47, "Loongson HDMI",		MODEL_LOONGSON),
>  	HDA_CODEC_ID_MODEL(0x10951390, "SiI1390 HDMI",		MODEL_GENERIC),
>  	HDA_CODEC_ID_MODEL(0x10951392, "SiI1392 HDMI",		MODEL_GENERIC),
>  	HDA_CODEC_ID_MODEL(0x11069f84, "VX11 HDMI/DP",		MODEL_GENERIC),
> diff --git a/sound/hda/common/jack.c b/sound/hda/common/jack.c
> index 98ba1c4d5ba4..1f0ebf9cd151 100644
> --- a/sound/hda/common/jack.c
> +++ b/sound/hda/common/jack.c
> @@ -58,6 +58,10 @@ static u32 read_pin_sense(struct hda_codec *codec, hda_nid_t nid, int dev_id)
>  				  AC_VERB_GET_PIN_SENSE, dev_id);
>  	if (codec->inv_jack_detect)
>  		val ^= AC_PINSENSE_PRESENCE;
> +	if (codec->eld_jack_detect) {
> +		val &= ~AC_PINSENSE_PRESENCE;
> +		val |= !!(val & AC_PINSENSE_ELDV) << 31;
> +	}

IMO it's worth for a comment in the above; basically it's faking the
AC_PINSENSE_PRESENCE from AC_PINSENSE_ELDV bit, which explains the
magic shift number.


thanks,

Takashi