Hi guys,
Anssi, thank you very much for your work! I'll test the patch asap and I'll keep you posted.
Takashi, where can I get patched kernel sources, or on which branch do I apply the patch to?
Thanks
Etienne
Le 2 sept. 2013 à 15:06, Takashi Iwai <tiwai@xxxxxxx> a écrit :
> At Sun, 1 Sep 2013 14:36:47 +0300,
> Anssi Hannula wrote:
>>
>> hdmi_channel_allocation() tries to find a HDMI channel allocation that
>> matches the number channels in the playback stream and contains only
>> speakers that the HDMI sink has reported as available via EDID. If no
>> such allocation is found, 0 (stereo audio) is used.
>>
>> Using CA 0 causes the audio causes the sink to discard everything except
>> the first two channels (front left and front right).
>>
>> However, the sink may be capable of receiving more channels than it has
>> speakers (and then perform downmix or discard the extra channels), in
>> which case it is preferable to use a CA that contains extra channels
>> than to use CA 0 which discards all the non-stereo channels.
>>
>> Additionally, it seems that HBR (HD) passthrough output does not work on
>> Intel HDMI codecs when CA is set to 0 (possibly the codec zeroes
>> channels not present in CA). This happens with all receivers that report
>> a 5.1 speaker mask since a HBR stream is carried on 8 channels to the
>> codec.
>>
>> Add a fallback in the CA selection so that the CA channel count at least
>> matches the stream channel count, even if the stream contains channels
>> not present in the sink speaker descriptor.
>>
>> Thanks to GrimGriefer at OpenELEC forums for discovering that changing
>> the sink speaker mask allowed HBR output.
>>
>> Reported-by: GrimGriefer
>> Reported-by: Ashecrow
>> Reported-by: Frank Zafka <kafkaesque1978@xxxxxxxxx>
>> Reported-by: Peter Frühberger <fritsch@xxxxxxxx>
>> Signed-off-by: Anssi Hannula <anssi.hannula@xxxxxx>
>> Cc: <stable@xxxxxxxxxxxxxxx>
>> ---
>>
>> Hopefully this fixes HBR (HD passthrough) for the remaining Intel users
>> who were still experiencing problems.
>
> Thanks, I applied the patch now.
>
>
>> BTW, the hdmi_channel_allocation() logic seems also otherwise somewhat
>> suspect to me. Shouldn't we always select an allocation matching ALSA
>> channel mapping, instead of re-assigning channels received from
>> userspace "randomly" to sink speakers (in case of unusual sink speaker
>> mask)?
>
> If per_pin->chmap_set is set beforehand,
> hdmi_manual_channel_allocation() is called instead. So it should be
> fine.
>
>
> Takashi
>
>> Anyway, I let it be for now at least.
>>
>>
>> sound/pci/hda/patch_hdmi.c | 11 +++++++++++
>> 1 file changed, 11 insertions(+)
>>
>> diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
>> index 030ca86..354fc55 100644
>> --- a/sound/pci/hda/patch_hdmi.c
>> +++ b/sound/pci/hda/patch_hdmi.c
>> @@ -551,6 +551,17 @@ static int hdmi_channel_allocation(struct hdmi_eld *eld, int channels)
>> }
>> }
>>
>> + if (!ca) {
>> + /* if there was no match, select the regular ALSA channel
>> + * allocation with the matching number of channels */
>> + for (i = 0; i < ARRAY_SIZE(channel_allocations); i++) {
>> + if (channels == channel_allocations[i].channels) {
>> + ca = channel_allocations[i].ca_index;
>> + break;
>> + }
>> + }
>> + }
>> +
>> snd_print_channel_allocation(eld->info.spk_alloc, buf, sizeof(buf));
>> snd_printdd("HDMI: select CA 0x%x for %d-channel allocation: %s\n",
>> ca, channels, buf);
>> --
>> 1.8.1.5
>>
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html