[alsa-devel] [PATCH RFC 18/21] ALSA: pcm: calculate non-mask/non-interval parameters always when possible

[Takashi Sakamoto]

A structure for parameters of PCM runtime has parameters which are
not classified as mask/interval type. They are decided only when
corresponding normal parameters have unique values.
 * struct snd_pcm_hw_params.msbits
 * struct snd_pcm_hw_params.rate_num
 * struct snd_pcm_hw_params.rate_den
 * struct snd_pcm_hw_params.fifo_size

Current implementation of hw_params ioctl sometimes doesn't decide these
parameters even if corresponding parameters are fixed, because these
parameters are evaluated before a call of snd_pcm_hw_params_choose().

This commit adds a helper function to process the parameters and call it
in proper positions.

Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
---
 sound/core/pcm_native.c | 71 ++++++++++++++++++++++++++++++-------------------
 1 file changed, 44 insertions(+), 27 deletions(-)

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 00d5aff..2875895 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -456,12 +456,45 @@ static int constrain_params_by_rules(struct snd_pcm_substream *substream,
 	return 0;
 }
 
-int snd_pcm_hw_refine(struct snd_pcm_substream *substream, 
+static int fixup_unreferenced_params(struct snd_pcm_substream *substream,
+				     struct snd_pcm_hw_params *params)
+{
+	const struct snd_mask *m;
+	const struct snd_interval *i;
+	int err;
+
+	if (!params->msbits) {
+		i = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
+		if (snd_interval_single(i))
+			params->msbits = snd_interval_value(i);
+	}
+
+	if (!params->rate_den) {
+		i = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE);
+		if (snd_interval_single(i)) {
+			params->rate_num = snd_interval_value(i);
+			params->rate_den = 1;
+		}
+	}
+
+	if (!params->fifo_size) {
+		m = hw_param_mask_c(params, SNDRV_PCM_HW_PARAM_FORMAT);
+		i = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_CHANNELS);
+		if (snd_mask_single(m) && snd_interval_single(i)) {
+			err = substream->ops->ioctl(substream,
+					SNDRV_PCM_IOCTL1_FIFO_SIZE, params);
+			if (err < 0)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
+int snd_pcm_hw_refine(struct snd_pcm_substream *substream,
 		      struct snd_pcm_hw_params *params)
 {
 	struct snd_pcm_hardware *hw;
-	struct snd_mask *m = NULL;
-	struct snd_interval *i = NULL;
 	struct snd_pcm_hw_constraints *constrs;
 	int changed;
 
@@ -487,20 +520,6 @@ int snd_pcm_hw_refine(struct snd_pcm_substream *substream,
 	if (changed < 0)
 		return changed;
 
-	if (!params->msbits) {
-		i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
-		if (snd_interval_single(i))
-			params->msbits = snd_interval_value(i);
-	}
-
-	if (!params->rate_den) {
-		i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
-		if (snd_interval_single(i)) {
-			params->rate_num = snd_interval_value(i);
-			params->rate_den = 1;
-		}
-	}
-
 	hw = &substream->runtime->hw;
 	if (!params->info) {
 		params->info = hw->info & ~(SNDRV_PCM_INFO_FIFO_IN_FRAMES |
@@ -509,17 +528,9 @@ int snd_pcm_hw_refine(struct snd_pcm_substream *substream,
 			params->info &= ~(SNDRV_PCM_INFO_MMAP |
 					  SNDRV_PCM_INFO_MMAP_VALID);
 	}
-	if (!params->fifo_size) {
-		m = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
-		i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
-		if (snd_mask_single(m) && snd_interval_single(i)) {
-			changed = substream->ops->ioctl(substream,
-					SNDRV_PCM_IOCTL1_FIFO_SIZE, params);
-			if (changed < 0)
-				return changed;
-		}
-	}
+
 	params->rmask = 0;
+
 	return 0;
 }
 
@@ -600,6 +611,8 @@ static int snd_pcm_hw_refine_user(struct snd_pcm_substream *substream,
 		return PTR_ERR(params);
 
 	err = snd_pcm_hw_refine(substream, params);
+	if (err >= 0)
+		err = fixup_unreferenced_params(substream, params);
 	if (copy_to_user(_params, params, sizeof(*params))) {
 		if (!err)
 			err = -EFAULT;
@@ -679,6 +692,10 @@ static int snd_pcm_hw_params(struct snd_pcm_substream *substream,
 	if (err < 0)
 		goto _error;
 
+	err = fixup_unreferenced_params(substream, params);
+	if (err < 0)
+		goto _error;
+
 	if (substream->ops->hw_params != NULL) {
 		err = substream->ops->hw_params(substream, params);
 		if (err < 0)
-- 
2.9.3