ALSA: intelhdmi - sticky stream id and format
We tracked down the first-0.5s-hdmi-audio-samples-lost problem to the
AC_VERB_SET_CHANNEL_STREAMID command. It is suspected that many HDMI
sinks need some time to adapt to the new state.
The workaround is to avoid changing stream id/format whenever possible.
Proposed by David.
Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/patch_intelhdmi.c b/sound/pci/hda/patch_intelhdmi.c
index abb056f..8a1cf9d 100644
--- a/sound/pci/hda/patch_intelhdmi.c
+++ b/sound/pci/hda/patch_intelhdmi.c
@@ -772,6 +772,31 @@
* Callbacks
*/
+static void hdmi_setup_stream(struct hda_codec *codec, hda_nid_t nid,
+ u32 stream_tag, int format)
+{
+ int tag;
+ int fmt;
+
+ tag = snd_hda_codec_read(codec, nid, 0, AC_VERB_GET_CONV, 0) >> 4;
+ fmt = snd_hda_codec_read(codec, nid, 0, AC_VERB_GET_STREAM_FORMAT, 0);
+
+ snd_printdd("hdmi_setup_stream: "
+ "NID=0x%x, %sstream=0x%x, %sformat=0x%x\n",
+ nid,
+ tag == stream_tag ? "" : "new-",
+ stream_tag,
+ fmt == format ? "" : "new-",
+ format);
+
+ if (tag != stream_tag)
+ snd_hda_codec_write(codec, nid, 0,
+ AC_VERB_SET_CHANNEL_STREAMID, stream_tag << 4);
+ if (fmt != format)
+ snd_hda_codec_write(codec, nid, 0,
+ AC_VERB_SET_STREAM_FORMAT, format);
+}
+
static int intel_hdmi_playback_pcm_prepare(struct hda_pcm_stream *hinfo,
struct hda_codec *codec,
unsigned int stream_tag,
@@ -783,7 +808,7 @@
hdmi_setup_audio_infoframe(codec, hinfo->nid, substream);
- snd_hda_codec_setup_stream(codec, hinfo->nid, stream_tag, 0, format);
+ hdmi_setup_stream(codec, hinfo->nid, stream_tag, format);
return 0;
}
@@ -791,7 +816,6 @@
struct hda_codec *codec,
struct snd_pcm_substream *substream)
{
- snd_hda_codec_cleanup_stream(codec, hinfo->nid);
return 0;
}