At Wed, 2 Oct 2013 21:13:32 +0300,
Anssi Hannula wrote:
>
> Currently hdmi_setup_audio_infoframe() reprograms the HDA channel
> mapping only when the infoframe is not up-to-date or the non-PCM flag
> has changed.
>
> However, when just the channel map has been changed, the infoframe may
> still be up-to-date and non-PCM flag may not have changed, so the new
> channel map is not actually programmed into the HDA codec.
>
> Notably, this failing case is also always triggered when the device is
> already in a prepared state and a new channel map is configured while
> changing only the channel positions (for example, plain
> "speaker-test -c2 -m FR,FL").
>
> Fix that by keeping track of the last programmed channel map and making
> hdmi_setup_audio_infoframe() always update the hardware mapping if the
> channel map has changed.
Hmm, maybe it's easier (and safer) to remove the check and always call
hdmi_setup_channel_mapping()? Of course, the drawback is the
unnecessary verbs, but it's not too much.
> Signed-off-by: Anssi Hannula <anssi.hannula@xxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx>
> ---
>
> BTW, is there some mechanism preventing hdmi_chmap_ctl_put() to be called
> at the same time with generic_hdmi_playback_pcm_prepare() that I didn't
> see with a quick look?
> Both of them call hdmi_setup_audio_infoframe() which is not thread-safe.
Yeah, we need to introduce a mutex there.
thanks,
Takashi
> sound/pci/hda/patch_hdmi.c | 14 +++++++++++---
> 1 file changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
> index 7ea0245..09f38a1 100644
> --- a/sound/pci/hda/patch_hdmi.c
> +++ b/sound/pci/hda/patch_hdmi.c
> @@ -74,6 +74,8 @@ struct hdmi_spec_per_pin {
> bool non_pcm;
> bool chmap_set; /* channel-map override by ALSA API? */
> unsigned char chmap[8]; /* ALSA API channel-map */
> + bool last_chmap_set; /* channel-map override programmed? */
> + unsigned char last_chmap[8]; /* last programmed channel-map */
> char pcm_name[8]; /* filled in build_pcm callbacks */
> };
>
> @@ -955,15 +957,21 @@ static void hdmi_setup_audio_infoframe(struct hda_codec *codec,
> ai.bytes, sizeof(ai));
> hdmi_start_infoframe_trans(codec, pin_nid);
> } else {
> - /* For non-pcm audio switch, setup new channel mapping
> - * accordingly */
> - if (per_pin->non_pcm != non_pcm)
> + /* For non-pcm audio switch or channel-map switch,
> + * setup new channel mapping accordingly */
> + if (per_pin->non_pcm != non_pcm
> + || per_pin->chmap_set != per_pin->last_chmap_set
> + || (per_pin->chmap_set && memcmp(per_pin->chmap, per_pin->last_chmap,
> + ARRAY_SIZE(per_pin->chmap)) != 0))
> hdmi_setup_channel_mapping(codec, pin_nid, non_pcm, ca,
> channels, per_pin->chmap,
> per_pin->chmap_set);
> }
>
> per_pin->non_pcm = non_pcm;
> + per_pin->last_chmap_set = per_pin->chmap_set;
> + if (per_pin->chmap_set)
> + memcpy(per_pin->last_chmap, per_pin->chmap, ARRAY_SIZE(per_pin->chmap));
> }
>
>
> --
> 1.8.1.5
>
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