ALSA: pcm: add a helper function to constrain interval-type parameters

Application of constraints to interval-type parameters for PCM substream
is done in a call of snd_pcm_hw_refine(), while the function includes
much codes and is not enough friendly to readers.

This commit splits the codes to a separated function so that readers can
get it easily. I leave desicion into compilers to merge the function into
its callee.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 1dee5f9..7e811ac 100644 (file)
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -286,6 +286,39 @@ static int constrain_mask_params(struct snd_pcm_substream *substream,
        return 0;
 }
 
+static int constrain_interval_params(struct snd_pcm_substream *substream,
+                                    struct snd_pcm_hw_params *params)
+{
+       struct snd_pcm_hw_constraints *constrs =
+                                       &substream->runtime->hw_constraints;
+       struct snd_interval *i;
+       unsigned int k;
+       struct snd_interval old_interval;
+       int changed;
+
+       for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++) {
+               i = hw_param_interval(params, k);
+               if (snd_interval_empty(i))
+                       return -EINVAL;
+               if (!(params->rmask & (1 << k)))
+                       continue;
+
+               if (trace_hw_interval_param_enabled())
+                       old_interval = *i;
+
+               changed = snd_interval_refine(i, constrs_interval(constrs, k));
+
+               trace_hw_interval_param(substream, k, 0, &old_interval, i);
+
+               if (changed)
+                       params->cmask |= 1 << k;
+               if (changed < 0)
+                       return changed;
+       }
+
+       return 0;
+}
+
 int snd_pcm_hw_refine(struct snd_pcm_substream *substream, 
                      struct snd_pcm_hw_params *params)
 {
@@ -316,25 +349,9 @@ int snd_pcm_hw_refine(struct snd_pcm_substream *substream,
        if (err < 0)
                return err;
 
-       for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++) {
-               i = hw_param_interval(params, k);
-               if (snd_interval_empty(i))
-                       return -EINVAL;
-               if (!(params->rmask & (1 << k)))
-                       continue;
-
-               if (trace_hw_interval_param_enabled())
-                       old_interval = *i;
-
-               changed = snd_interval_refine(i, constrs_interval(constrs, k));
-
-               trace_hw_interval_param(substream, k, 0, &old_interval, i);
-
-               if (changed)
-                       params->cmask |= 1 << k;
-               if (changed < 0)
-                       return changed;
-       }
+       err = constrain_interval_params(substream, params);
+       if (err < 0)
+               return err;
 
        for (k = 0; k < constrs->rules_num; k++)
                rstamps[k] = 0;