Re: [PATCH v2] ALSA: hda - verify pin:cvt connection on preparing a stream for Intel HDMI codec

[Takashi Iwai <tiwai@suse.de>]

At Thu, 20 Mar 2014 13:01:06 +0800,
mengdong.lin@intel.com wrote:
> 
> From: Mengdong Lin <mengdong.lin@intel.com>
> 
> This is a temporary fix for some Intel HDMI codecs to avoid no sound output for
> a resuming playback after S3.
> 
> After S3, the audio driver restores pin:cvt connection selections by
> snd_hda_codec_resume_cache(). However this can happen before the gfx side is
> ready and such connect selection is overlooked by HW. After gfx is ready, the
> pins make the default selection again. And this will cause multiple pins share
> a same convertor and mute control will affect each other. Thus a resumed audio
> playback become silent after S3.
> 
> This patch verifies pin:cvt connection on preparing a stream, to assure the pin
> selects the right convetor and an assigned convertor is not shared by other
> unused pins. Apply this fix-up on Haswell, Broadwell and Valleyview (Baytrail).
> 
> We need this temporary fix before a reliable software communication channel is
> established between audio and gfx, to sync audio/gfx operations.
> 
> Signed-off-by: Mengdong Lin <mengdong.lin@intel.com>

Thanks, applied.


Takashi

> 
> diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
> index 3ab7063..585c271 100644
> --- a/sound/pci/hda/patch_hdmi.c
> +++ b/sound/pci/hda/patch_hdmi.c
> @@ -68,6 +68,7 @@ struct hdmi_spec_per_pin {
>  	hda_nid_t pin_nid;
>  	int num_mux_nids;
>  	hda_nid_t mux_nids[HDA_MAX_CONNECTIONS];
> +	int mux_idx;
>  	hda_nid_t cvt_nid;
>  
>  	struct hda_codec *codec;
> @@ -1342,6 +1343,8 @@ static int hdmi_choose_cvt(struct hda_codec *codec,
>  	if (cvt_idx == spec->num_cvts)
>  		return -ENODEV;
>  
> +	per_pin->mux_idx = mux_idx;
> +
>  	if (cvt_id)
>  		*cvt_id = cvt_idx;
>  	if (mux_id)
> @@ -1350,6 +1353,22 @@ static int hdmi_choose_cvt(struct hda_codec *codec,
>  	return 0;
>  }
>  
> +/* Assure the pin select the right convetor */
> +static void intel_verify_pin_cvt_connect(struct hda_codec *codec,
> +			struct hdmi_spec_per_pin *per_pin)
> +{
> +	hda_nid_t pin_nid = per_pin->pin_nid;
> +	int mux_idx, curr;
> +
> +	mux_idx = per_pin->mux_idx;
> +	curr = snd_hda_codec_read(codec, pin_nid, 0,
> +					  AC_VERB_GET_CONNECT_SEL, 0);
> +	if (curr != mux_idx)
> +		snd_hda_codec_write_cache(codec, pin_nid, 0,
> +					    AC_VERB_SET_CONNECT_SEL,
> +					    mux_idx);
> +}
> +
>  /* Intel HDMI workaround to fix audio routing issue:
>   * For some Intel display codecs, pins share the same connection list.
>   * So a conveter can be selected by multiple pins and playback on any of these
> @@ -1751,6 +1770,19 @@ static int generic_hdmi_playback_pcm_prepare(struct hda_pcm_stream *hinfo,
>  	bool non_pcm;
>  	int pinctl;
>  
> +	if (is_haswell_plus(codec) || is_valleyview(codec)) {
> +		/* Verify pin:cvt selections to avoid silent audio after S3.
> +		 * After S3, the audio driver restores pin:cvt selections
> +		 * but this can happen before gfx is ready and such selection
> +		 * is overlooked by HW. Thus multiple pins can share a same
> +		 * default convertor and mute control will affect each other,
> +		 * which can cause a resumed audio playback become silent
> +		 * after S3.
> +		 */
> +		intel_verify_pin_cvt_connect(codec, per_pin);
> +		intel_not_share_assigned_cvt(codec, pin_nid, per_pin->mux_idx);
> +	}
> +
>  	non_pcm = check_non_pcm_per_cvt(codec, cvt_nid);
>  	mutex_lock(&per_pin->lock);
>  	per_pin->channels = substream->runtime->channels;
> -- 
> 1.8.1.2
>