[alsa-devel] [PATCH] ALSA: hda - Re-setup HDMI pin and audio infoframe on stream switches

[David Henningsson]

On 09/03/2013 11:57 AM, Takashi Iwai wrote:
> When the transcoder:port mapping on Haswell HDMI/DP audio is changed
> during the stream playback, the sound gets lost.  Typically this
> problem is seen when the user switches the graphics mode from eDP+DP
> to DP-only configuration, where CRTC 1 is used for DP in the former
> while CRTC 0 is used for the latter.
> 
> The graphics controller notifies the change via the normal ELD update
> procedure, so we get the intrinsic event.  For enabling the sound
> again, the HDMI audio driver needs to reset the pin and set up the
> audio infoframe again.

Thanks for working on this!

See a review comment below.

> 
> This patch achieves it by:
> - keep the current status of channels and info frame setup in per_pin
>   struct,
> - check the reconnection in the intrinsic event handler,
> - reset the pin and the re-invoke hdmi_setup_audio_infoframe()
>   accordingly.
> 
> The hdmi_setup_audio_infoframe() function has been changed, too, so
> that it can be invoked without passing the substream instance.
> 
> The patch is mostly based on the work by Mengdong Lin.
> 
> Cc: Mengdong Lin <mengdong.lin at intel.com>
> Cc: <stable at vger.kernel.org>
> Signed-off-by: Takashi Iwai <tiwai at suse.de>
> ---
>  sound/pci/hda/patch_hdmi.c | 41 +++++++++++++++++++++++++++++++----------
>  1 file changed, 31 insertions(+), 10 deletions(-)
> 
> diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
> index b83b14f..22b5089 100644
> --- a/sound/pci/hda/patch_hdmi.c
> +++ b/sound/pci/hda/patch_hdmi.c
> @@ -67,6 +67,8 @@ struct hdmi_spec_per_pin {
>  	struct delayed_work work;
>  	struct snd_kcontrol *eld_ctl;
>  	int repoll_count;
> +	bool setup; /* the stream has been set up by prepare callback */
> +	int channels; /* current number of channels */
>  	bool non_pcm;
>  	bool chmap_set;		/* channel-map override by ALSA API? */
>  	unsigned char chmap[8]; /* ALSA API channel-map */
> @@ -879,18 +881,19 @@ static bool hdmi_infoframe_uptodate(struct hda_codec *codec, hda_nid_t pin_nid,
>  	return true;
>  }
>  
> -static void hdmi_setup_audio_infoframe(struct hda_codec *codec, int pin_idx,
> -				       bool non_pcm,
> -				       struct snd_pcm_substream *substream)
> +static void hdmi_setup_audio_infoframe(struct hda_codec *codec,
> +				       struct hdmi_spec_per_pin *per_pin,
> +				       bool non_pcm)
>  {
> -	struct hdmi_spec *spec = codec->spec;
> -	struct hdmi_spec_per_pin *per_pin = get_pin(spec, pin_idx);
>  	hda_nid_t pin_nid = per_pin->pin_nid;
> -	int channels = substream->runtime->channels;
> +	int channels = per_pin->channels;
>  	struct hdmi_eld *eld;
>  	int ca;
>  	union audio_infoframe ai;
>  
> +	if (!channels)
> +		return;
> +
>  	eld = &per_pin->sink_eld;
>  	if (!eld->monitor_present)
>  		return;
> @@ -1341,6 +1344,7 @@ static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll)
>  		eld_changed = true;
>  	}
>  	if (update_eld) {
> +		bool old_eld_valid = pin_eld->eld_valid;
>  		pin_eld->eld_valid = eld->eld_valid;
>  		eld_changed = pin_eld->eld_size != eld->eld_size ||
>  			      memcmp(pin_eld->eld_buffer, eld->eld_buffer,
> @@ -1350,6 +1354,18 @@ static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll)
>  			       eld->eld_size);
>  		pin_eld->eld_size = eld->eld_size;
>  		pin_eld->info = eld->info;
> +
> +		/* Haswell-specific workaround: re-setup when the transcoder is
> +		 * changed during the stream playback
> +		 */
> +		if (codec->vendor_id == 0x80862807 &&
> +		    eld->eld_valid && !old_eld_valid && per_pin->setup) {
> +			snd_hda_codec_write(codec, pin_nid, 0,
> +					    AC_VERB_SET_AMP_GAIN_MUTE,
> +					    AMP_OUT_UNMUTE);

If the system is deliberately muted by turning off "IEC958 Playback
Switch", are we now ignoring that and turning it back on?

Also, this looks a bit like the workaround I added a while back
(83f26ad2c909083fa6 - ALSA: hda - fixup D3 pin and right channel mute on
Haswell HDMI audio) is there a possibility we need to fix up D3 as well
here? I e, call haswell_verify_pin_D0 rather than just setting the mute?
Or perhaps move the call to haswell_verify_pin_D0 from hdmi_setup_stream
to hdme_setup_audio_infoframe ?

> +			hdmi_setup_audio_infoframe(codec, per_pin,
> +						   per_pin->non_pcm);
> +		}
>  	}
>  	mutex_unlock(&pin_eld->lock);
>  
> @@ -1522,14 +1538,17 @@ static int generic_hdmi_playback_pcm_prepare(struct hda_pcm_stream *hinfo,
>  	hda_nid_t cvt_nid = hinfo->nid;
>  	struct hdmi_spec *spec = codec->spec;
>  	int pin_idx = hinfo_to_pin_index(spec, hinfo);
> -	hda_nid_t pin_nid = get_pin(spec, pin_idx)->pin_nid;
> +	struct hdmi_spec_per_pin *per_pin = get_pin(spec, pin_idx);
> +	hda_nid_t pin_nid = per_pin->pin_nid;
>  	bool non_pcm;
>  
>  	non_pcm = check_non_pcm_per_cvt(codec, cvt_nid);
> +	per_pin->channels = substream->runtime->channels;
> +	per_pin->setup = true;
>  
>  	hdmi_set_channel_count(codec, cvt_nid, substream->runtime->channels);
>  
> -	hdmi_setup_audio_infoframe(codec, pin_idx, non_pcm, substream);
> +	hdmi_setup_audio_infoframe(codec, per_pin, non_pcm);
>  
>  	return hdmi_setup_stream(codec, cvt_nid, pin_nid, stream_tag, format);
>  }
> @@ -1569,6 +1588,9 @@ static int hdmi_pcm_close(struct hda_pcm_stream *hinfo,
>  		snd_hda_spdif_ctls_unassign(codec, pin_idx);
>  		per_pin->chmap_set = false;
>  		memset(per_pin->chmap, 0, sizeof(per_pin->chmap));
> +
> +		per_pin->setup = false;
> +		per_pin->channels = 0;
>  	}
>  
>  	return 0;
> @@ -1704,8 +1726,7 @@ static int hdmi_chmap_ctl_put(struct snd_kcontrol *kcontrol,
>  	per_pin->chmap_set = true;
>  	memcpy(per_pin->chmap, chmap, sizeof(chmap));
>  	if (prepared)
> -		hdmi_setup_audio_infoframe(codec, pin_idx, per_pin->non_pcm,
> -					   substream);
> +		hdmi_setup_audio_infoframe(codec, per_pin, per_pin->non_pcm);
>  
>  	return 0;
>  }
> 



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