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77 lines
2.8 KiB
Plaintext
77 lines
2.8 KiB
Plaintext
From a6024295fd3290a8c9c5519a03316081ee82378a Mon Sep 17 00:00:00 2001
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From: Anssi Hannula <anssi.hannula@iki.fi>
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Date: Sat, 16 Feb 2013 17:42:46 +0200
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Subject: [PATCH] ALSA: hda - Avoid outputting HDMI audio before prepare() and
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after close()
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Some HDMI codecs (at least NVIDIA 0x10de000b:0x10de0101:0x100100) start
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transmitting an empty audio stream as soon as PIN_OUT and AC_DIG1_ENABLE
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are enabled.
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Since commit 6169b673618bf0b2518ce413b54925782a603f06 ("ALSA: hda -
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Always turn on pins for HDMI/DP") this happens at first open() time, and
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will continue even after close().
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Additionally, some codecs (at least Intel PantherPoint HDMI) currently
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continue transmitting HDMI audio even after close() in case some actual
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audio was output after open() (this happens regardless of PIN_OUT).
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Empty HDMI audio transmission when not intended has the effect that a
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possible HDMI audio sink/receiver may prefer the empty HDMI audio stream
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over an actual audio stream on its S/PDIF inputs.
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To avoid the issue before first prepare(), set stream format to 0 on
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codec initialization. 0 is not a valid format value for HDMI and will
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prevent the audio stream from being output.
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Additionally, at close() time, make sure that the stream is cleaned up.
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This will ensure that the format is reset to 0 at that time, preventing
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audio from being output in that case.
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Thanks to OpenELEC developers and users for their help in investigating
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this issue on the affected NVIDIA "ION2" hardware. Testing of the final
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version on NVIDIA ION2 was done by OpenELEC user "MrXIII". Testing on
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Intel PantherPoint was done by myself.
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Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
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Cc: stable@vger.kernel.org
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---
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sound/pci/hda/patch_hdmi.c | 14 ++++++++++++++
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1 file changed, 14 insertions(+)
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diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
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index 807a2aa..bcb83c7 100644
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--- a/sound/pci/hda/patch_hdmi.c
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+++ b/sound/pci/hda/patch_hdmi.c
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@@ -1253,6 +1253,14 @@ static int hdmi_add_cvt(struct hda_codec *codec, hda_nid_t cvt_nid)
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if (err < 0)
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return err;
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+ /*
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+ * Some HDMI codecs (at least NVIDIA 0x10de000b:0x10de0101:0x100100)
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+ * start transmitting an empty audio stream as soon as PIN_OUT and
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+ * AC_DIG1_ENABLE are enabled, which happens at open() time.
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+ * To avoid that, set format to 0, which is not valid for HDMI.
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+ */
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+ snd_hda_codec_write(codec, cvt_nid, 0, AC_VERB_SET_STREAM_FORMAT, 0);
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+
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spec->num_cvts++;
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return 0;
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@@ -1372,6 +1380,12 @@ static int hdmi_pcm_close(struct hda_pcm_stream *hinfo,
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struct hdmi_spec_per_pin *per_pin;
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if (hinfo->nid) {
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+ /*
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+ * Make sure no empty audio is output after this point by
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+ * setting stream format to 0, which is not valid for HDMI.
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+ */
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+ __snd_hda_codec_cleanup_stream(codec, hinfo->nid, 1);
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+
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cvt_idx = cvt_nid_to_cvt_index(spec, hinfo->nid);
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if (snd_BUG_ON(cvt_idx < 0))
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return -EINVAL;
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--
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1.7.10
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