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linux: hda - hdmi: Fallback to ALSA allocation when selecting CA

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This commit is contained in:
Stefan Saraev 2013-09-01 14:36:52 +03:00
parent e94c740b27
commit 31c67a6cc0
1 changed files with 70 additions and 0 deletions
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packages/linux/patches/3.10.10/linux-990.07-ALSA-hda-hdmi-Fallback-to-ALSA-allocation-when-selec.patch vendored Normal file
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@ -0,0 +1,70 @@
From d0929f7068e8025a3d9ccf5dd7bea8dc0d887a49 Mon Sep 17 00:00:00 2001
From: Anssi Hannula <anssi.hannula@iki.fi>
Date: Sun, 1 Sep 2013 13:01:09 +0300
Subject: [PATCH] ALSA: hda - hdmi: Fallback to ALSA allocation when selecting
CA
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
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 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 streams 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@gmail.com>
Reported-by: Peter Frühberger <fritsch@xbmc.org>
Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
Cc: <stable@vger.kernel.org>
---
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