ALSA: hda - Don't reset BDL unnecessarily

So far, the prepare callback is called multiple times, BDL entries
are reset and re-programmed at each time.

This patch adds the check to avoid the reset of BDL entries when the
same parameters are used.

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 6bcf5af..ba97795 100644 (file)
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -1076,8 +1076,7 @@ static int azx_setup_periods(struct azx *chip,
        azx_sd_writel(azx_dev, SD_BDLPL, 0);
        azx_sd_writel(azx_dev, SD_BDLPU, 0);
 
-       period_bytes = snd_pcm_lib_period_bytes(substream);
-       azx_dev->period_bytes = period_bytes;
+       period_bytes = azx_dev->period_bytes;
        periods = azx_dev->bufsize / period_bytes;
 
        /* program the initial BDL entries */
@@ -1124,9 +1123,6 @@ static int azx_setup_periods(struct azx *chip,
  error:
        snd_printk(KERN_ERR "Too many BDL entries: buffer=%d, period=%d\n",
                   azx_dev->bufsize, period_bytes);
-       /* reset */
-       azx_sd_writel(azx_dev, SD_BDLPL, 0);
-       azx_sd_writel(azx_dev, SD_BDLPU, 0);
        return -EINVAL;
 }
 
@@ -1429,6 +1425,11 @@ static int azx_pcm_close(struct snd_pcm_substream *substream)
 static int azx_pcm_hw_params(struct snd_pcm_substream *substream,
                             struct snd_pcm_hw_params *hw_params)
 {
+       struct azx_dev *azx_dev = get_azx_dev(substream);
+
+       azx_dev->bufsize = 0;
+       azx_dev->period_bytes = 0;
+       azx_dev->format_val = 0;
        return snd_pcm_lib_malloc_pages(substream,
                                        params_buffer_bytes(hw_params));
 }
@@ -1443,6 +1444,9 @@ static int azx_pcm_hw_free(struct snd_pcm_substream *substream)
        azx_sd_writel(azx_dev, SD_BDLPL, 0);
        azx_sd_writel(azx_dev, SD_BDLPU, 0);
        azx_sd_writel(azx_dev, SD_CTL, 0);
+       azx_dev->bufsize = 0;
+       azx_dev->period_bytes = 0;
+       azx_dev->format_val = 0;
 
        hinfo->ops.cleanup(hinfo, apcm->codec, substream);
 
@@ -1456,23 +1460,37 @@ static int azx_pcm_prepare(struct snd_pcm_substream *substream)
        struct azx_dev *azx_dev = get_azx_dev(substream);
        struct hda_pcm_stream *hinfo = apcm->hinfo[substream->stream];
        struct snd_pcm_runtime *runtime = substream->runtime;
+       unsigned int bufsize, period_bytes, format_val;
+       int err;
 
-       azx_dev->bufsize = snd_pcm_lib_buffer_bytes(substream);
-       azx_dev->format_val = snd_hda_calc_stream_format(runtime->rate,
-                                                        runtime->channels,
-                                                        runtime->format,
-                                                        hinfo->maxbps);
-       if (!azx_dev->format_val) {
+       format_val = snd_hda_calc_stream_format(runtime->rate,
+                                               runtime->channels,
+                                               runtime->format,
+                                               hinfo->maxbps);
+       if (!format_val) {
                snd_printk(KERN_ERR SFX
                           "invalid format_val, rate=%d, ch=%d, format=%d\n",
                           runtime->rate, runtime->channels, runtime->format);
                return -EINVAL;
        }
 
+       bufsize = snd_pcm_lib_buffer_bytes(substream);
+       period_bytes = snd_pcm_lib_period_bytes(substream);
+
        snd_printdd("azx_pcm_prepare: bufsize=0x%x, format=0x%x\n",
-                   azx_dev->bufsize, azx_dev->format_val);
-       if (azx_setup_periods(chip, substream, azx_dev) < 0)
-               return -EINVAL;
+                   bufsize, format_val);
+
+       if (bufsize != azx_dev->bufsize ||
+           period_bytes != azx_dev->period_bytes ||
+           format_val != azx_dev->format_val) {
+               azx_dev->bufsize = bufsize;
+               azx_dev->period_bytes = period_bytes;
+               azx_dev->format_val = format_val;
+               err = azx_setup_periods(chip, substream, azx_dev);
+               if (err < 0)
+                       return err;
+       }
+
        azx_setup_controller(chip, azx_dev);
        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                azx_dev->fifo_size = azx_sd_readw(azx_dev, SD_FIFOSIZE) + 1;