ALSA: hda - HDMI sticky stream tag support
When we run the following commands in turn (with
CONFIG_SND_HDA_POWER_SAVE_DEFAULT=0),
speaker-test -Dhw:0,3 -c2 -twav # HDMI
speaker-test -Dhw:0,0 -c2 -twav # Analog
The second command will produce sound in the analog lineout _as well as_
HDMI sink. The root cause is, device 0 "reuses" the same stream tag that
was used by device 3, and the "intelhdmi - sticky stream id" patch leaves
the HDMI codec in a functional state. So the HDMI codec happily accepts
the audio samples which reuse its stream tag.
The proposed solution is to remember the last device each azx_dev was
assigned to, and prefer to
1) reuse the azx_dev (and hence the stream tag) the HDMI codec last used
2) or assign a never-used azx_dev for HDMI
With this patch and the above two speaker-test commands,
HDMI codec will use stream tag 8 and Analog codec will use 5.
The stream tag used by HDMI codec won't be reused by others, as long
as we don't run out of the 4 playback azx_dev's. The legacy Analog
codec will continue to use stream tag 5 because its device id is 0
(this is a bit tricky).
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index ff8ad46c..ec9c348 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -356,6 +356,7 @@
*/
unsigned char stream_tag; /* assigned stream */
unsigned char index; /* stream index */
+ int device; /* last device number assigned to */
unsigned int opened :1;
unsigned int running :1;
@@ -1441,10 +1442,13 @@
*/
/* assign a stream for the PCM */
-static inline struct azx_dev *azx_assign_device(struct azx *chip, int stream)
+static inline struct azx_dev *
+azx_assign_device(struct azx *chip, struct snd_pcm_substream *substream)
{
int dev, i, nums;
- if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
+ struct azx_dev *res = NULL;
+
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
dev = chip->playback_index_offset;
nums = chip->playback_streams;
} else {
@@ -1453,10 +1457,15 @@
}
for (i = 0; i < nums; i++, dev++)
if (!chip->azx_dev[dev].opened) {
- chip->azx_dev[dev].opened = 1;
- return &chip->azx_dev[dev];
+ res = &chip->azx_dev[dev];
+ if (res->device == substream->pcm->device)
+ break;
}
- return NULL;
+ if (res) {
+ res->opened = 1;
+ res->device = substream->pcm->device;
+ }
+ return res;
}
/* release the assigned stream */
@@ -1505,7 +1514,7 @@
int err;
mutex_lock(&chip->open_mutex);
- azx_dev = azx_assign_device(chip, substream->stream);
+ azx_dev = azx_assign_device(chip, substream);
if (azx_dev == NULL) {
mutex_unlock(&chip->open_mutex);
return -EBUSY;