[alsa-devel] [PATCH] ALSA: hda - Avoid BDL position workaround when no_period_wakeup is set

[Takashi Iwai]

Originally the bogus period at BDL head was introduced as a workaround
for the mismatching position update at the period boundary, typically
seen on dmix.  However, for applications like PulseAudio that don't
require period wake ups, this workaround is just superfluous.  Thus
better to disable it when no_period_wakeup is given in hw_params.

Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/pci/hda/hda_intel.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 6a19f6a..76ec242 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -415,6 +415,7 @@ struct azx_dev {
 	 */
 	unsigned int insufficient :1;
 	unsigned int wc_marked:1;
+	unsigned int no_period_wakeup:1;
 };
 
 /* CORB/RIRB */
@@ -1419,7 +1420,7 @@ static int azx_setup_periods(struct azx *chip,
 	ofs = 0;
 	azx_dev->frags = 0;
 	pos_adj = bdl_pos_adj[chip->dev_index];
-	if (pos_adj > 0) {
+	if (!azx_dev->no_period_wakeup && pos_adj > 0) {
 		struct snd_pcm_runtime *runtime = substream->runtime;
 		int pos_align = pos_adj;
 		pos_adj = (pos_adj * runtime->rate + 47999) / 48000;
@@ -1435,8 +1436,7 @@ static int azx_setup_periods(struct azx *chip,
 			pos_adj = 0;
 		} else {
 			ofs = setup_bdle(chip, substream, azx_dev,
-					 &bdl, ofs, pos_adj,
-					 !substream->runtime->no_period_wakeup);
+					 &bdl, ofs, pos_adj, true);
 			if (ofs < 0)
 				goto error;
 		}
@@ -1449,7 +1449,7 @@ static int azx_setup_periods(struct azx *chip,
 		else
 			ofs = setup_bdle(chip, substream, azx_dev, &bdl, ofs,
 					 period_bytes,
-					 !substream->runtime->no_period_wakeup);
+					 !azx_dev->no_period_wakeup);
 		if (ofs < 0)
 			goto error;
 	}
@@ -1922,10 +1922,12 @@ static int azx_pcm_prepare(struct snd_pcm_substream *substream)
 
 	if (bufsize != azx_dev->bufsize ||
 	    period_bytes != azx_dev->period_bytes ||
-	    format_val != azx_dev->format_val) {
+	    format_val != azx_dev->format_val ||
+	    runtime->no_period_wakeup != azx_dev->no_period_wakeup) {
 		azx_dev->bufsize = bufsize;
 		azx_dev->period_bytes = period_bytes;
 		azx_dev->format_val = format_val;
+		azx_dev->no_period_wakeup = runtime->no_period_wakeup;
 		err = azx_setup_periods(chip, substream, azx_dev);
 		if (err < 0)
 			return err;
-- 
1.7.11.5