[PATCH V3 0/2] Support more sample rate in asrc

[PATCH V3 0/2] Support more sample rate in asrc

[S.j. Wang]

Support more sample rate in asrc

Shengjiu Wang (2):
  ASoC: fsl_asrc: replace the process_option table with function
  ASoC: fsl_asrc: Unify the supported input and output rate

Changes in v3
- remove FSL_ASRC_RATES
- refine fsl_asrc_sel_proc according to comments

Changes in v2
- add more comments in code
- add commit "Unify the supported input and output rate"

 sound/soc/fsl/fsl_asrc.c | 108 +++++++++++++++++++++++++++++++++--------------
 1 file changed, 76 insertions(+), 32 deletions(-)

-- 
1.9.1

[PATCH V3 1/2] ASoC: fsl_asrc: replace the process_option table with function

[S.j. Wang]

When we want to support more sample rate, for example 12kHz/24kHz
we need update the process_option table, if we want to support more
sample rate next time, the table need to be updated again. which
is not flexible.

We got a function fsl_asrc_sel_proc to replace the table, which can
give the pre-processing and post-processing options according to
the sample rate.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
 sound/soc/fsl/fsl_asrc.c | 78 +++++++++++++++++++++++++++++++++++-------------
 1 file changed, 58 insertions(+), 20 deletions(-)

diff --git a/sound/soc/fsl/fsl_asrc.c b/sound/soc/fsl/fsl_asrc.c
index 0b937924d2e4..d34d539d01f2 100644
--- a/sound/soc/fsl/fsl_asrc.c
+++ b/sound/soc/fsl/fsl_asrc.c
@@ -26,24 +26,6 @@
 #define pair_dbg(fmt, ...) \
 	dev_dbg(&asrc_priv->pdev->dev, "Pair %c: " fmt, 'A' + index, ##__VA_ARGS__)
 
-/* Sample rates are aligned with that defined in pcm.h file */
-static const u8 process_option[][12][2] = {
-	/* 8kHz 11.025kHz 16kHz 22.05kHz 32kHz 44.1kHz 48kHz   64kHz   88.2kHz 96kHz   176kHz  192kHz */
-	{{0, 1}, {0, 1}, {0, 1}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0},},	/* 5512Hz */
-	{{0, 1}, {0, 1}, {0, 1}, {0, 1}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0},},	/* 8kHz */
-	{{0, 2}, {0, 1}, {0, 1}, {0, 1}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0},},	/* 11025Hz */
-	{{1, 2}, {0, 2}, {0, 1}, {0, 1}, {0, 1}, {0, 1}, {0, 1}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0},},	/* 16kHz */
-	{{1, 2}, {1, 2}, {0, 2}, {0, 1}, {0, 1}, {0, 1}, {0, 1}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0},},	/* 22050Hz */
-	{{1, 2}, {2, 1}, {2, 1}, {0, 2}, {0, 1}, {0, 1}, {0, 1}, {0, 1}, {0, 1}, {0, 0}, {0, 0}, {0, 0},},	/* 32kHz */
-	{{2, 2}, {2, 2}, {2, 1}, {2, 1}, {0, 2}, {0, 1}, {0, 1}, {0, 1}, {0, 1}, {0, 1}, {0, 0}, {0, 0},},	/* 44.1kHz */
-	{{2, 2}, {2, 2}, {2, 1}, {2, 1}, {0, 2}, {0, 2}, {0, 1}, {0, 1}, {0, 1}, {0, 1}, {0, 0}, {0, 0},},	/* 48kHz */
-	{{2, 2}, {2, 2}, {2, 2}, {2, 1}, {1, 2}, {0, 2}, {0, 2}, {0, 1}, {0, 1}, {0, 1}, {0, 1}, {0, 0},},	/* 64kHz */
-	{{2, 2}, {2, 2}, {2, 2}, {2, 2}, {1, 2}, {1, 2}, {1, 2}, {1, 1}, {1, 1}, {1, 1}, {1, 1}, {1, 1},},	/* 88.2kHz */
-	{{2, 2}, {2, 2}, {2, 2}, {2, 2}, {1, 2}, {1, 2}, {1, 2}, {1, 1}, {1, 1}, {1, 1}, {1, 1}, {1, 1},},	/* 96kHz */
-	{{2, 2}, {2, 2}, {2, 2}, {2, 2}, {2, 2}, {2, 2}, {2, 2}, {2, 1}, {2, 1}, {2, 1}, {2, 1}, {2, 1},},	/* 176kHz */
-	{{2, 2}, {2, 2}, {2, 2}, {2, 2}, {2, 2}, {2, 2}, {2, 2}, {2, 1}, {2, 1}, {2, 1}, {2, 1}, {2, 1},},	/* 192kHz */
-};
-
 /* Corresponding to process_option */
 static int supported_input_rate[] = {
 	5512, 8000, 11025, 16000, 22050, 32000, 44100, 48000, 64000, 88200,
@@ -80,6 +62,54 @@
 static unsigned char *clk_map[2];
 
 /**
+ * Select the pre-processing and post-processing options
+ *
+ * inrate: input sample rate
+ * outrate: output sample rate
+ * pre_proc: return value for pre-processing option
+ * post_proc: return value for post-processing option
+ */
+static int fsl_asrc_sel_proc(int inrate, int outrate, int *pre_proc,
+			     int *post_proc)
+{
+	bool post_proc_cond2;
+	bool post_proc_cond0;
+
+	/* Does not support cases: Tsout > 8.125 * Tsin */
+	if (inrate * 8 > 65 * outrate)
+		return -EINVAL;
+
+	/* Otherwise, select pre_proc between [0, 2] */
+	if (inrate * 8 > 33 * outrate)
+		*pre_proc = 2;
+	else if (inrate * 8 > 15 * outrate) {
+		if (inrate > 152000)
+			*pre_proc = 2;
+		else
+			*pre_proc = 1;
+	} else if (inrate < 76000)
+		*pre_proc = 0;
+	else if (inrate > 152000)
+		*pre_proc = 2;
+	else
+		*pre_proc = 1;
+
+	/* Condition for selection of post-processing */
+	post_proc_cond2 = (inrate * 15 > outrate * 16 && outrate < 56000) ||
+		(inrate > 56000 && outrate < 56000);
+	post_proc_cond0 = inrate * 23 < outrate * 8;
+
+	if (post_proc_cond2)
+		*post_proc = 2;
+	else if (post_proc_cond0)
+		*post_proc = 0;
+	else
+		*post_proc = 1;
+
+	return 0;
+}
+
+/**
  * Request ASRC pair
  *
  * It assigns pair by the order of A->C->B because allocation of pair B,
@@ -239,8 +269,10 @@ static int fsl_asrc_config_pair(struct fsl_asrc_pair *pair)
 	u32 inrate, outrate, indiv, outdiv;
 	u32 clk_index[2], div[2];
 	int in, out, channels;
+	int pre_proc, post_proc;
 	struct clk *clk;
 	bool ideal;
+	int ret;
 
 	if (!config) {
 		pair_err("invalid pair config\n");
@@ -289,6 +321,12 @@ static int fsl_asrc_config_pair(struct fsl_asrc_pair *pair)
 		return -EINVAL;
 	}
 
+	ret = fsl_asrc_sel_proc(inrate, outrate, &pre_proc, &post_proc);
+	if (ret) {
+		pair_err("No supported pre-processing options\n");
+		return ret;
+	}
+
 	/* Validate input and output clock sources */
 	clk_index[IN] = clk_map[IN][config->inclk];
 	clk_index[OUT] = clk_map[OUT][config->outclk];
@@ -380,8 +418,8 @@ static int fsl_asrc_config_pair(struct fsl_asrc_pair *pair)
 	/* Apply configurations for pre- and post-processing */
 	regmap_update_bits(asrc_priv->regmap, REG_ASRCFG,
 			   ASRCFG_PREMODi_MASK(index) |	ASRCFG_POSTMODi_MASK(index),
-			   ASRCFG_PREMOD(index, process_option[in][out][0]) |
-			   ASRCFG_POSTMOD(index, process_option[in][out][1]));
+			   ASRCFG_PREMOD(index, pre_proc) |
+			   ASRCFG_POSTMOD(index, post_proc));
 
 	return fsl_asrc_set_ideal_ratio(pair, inrate, outrate);
 }
-- 
1.9.1

Re: [PATCH V3 1/2] ASoC: fsl_asrc: replace the process_option table with function

[Nicolin Chen]

Hi Shengjiu,

This looks better. Just a couple of more small comments inline.

On Wed, Apr 17, 2019 at 09:06:18AM +0000, S.j. Wang wrote:

> +static int fsl_asrc_sel_proc(int inrate, int outrate, int *pre_proc,
> +			     int *post_proc)

Just a nit: it looks better by grouping them two-two.

static int fsl_asrc_sel_proc(int inrate, int outrate,
			     int *pre_proc, int *post_proc)

> +	/* Condition for selection of post-processing */
> +	post_proc_cond2 = (inrate * 15 > outrate * 16 && outrate < 56000) ||
> +		(inrate > 56000 && outrate < 56000);

Could align the indentation:
	post_proc_cond2 = (inrate * 15 > outrate * 16 && outrate < 56000) ||
			  (inrate > 56000 && outrate < 56000);

Here:
> +	/* Does not support cases: Tsout > 8.125 * Tsin */
> +	if (inrate * 8 > 65 * outrate)
> +		return -EINVAL;
And here:
> +	ret = fsl_asrc_sel_proc(inrate, outrate, &pre_proc, &post_proc);
> +	if (ret) {
> +		pair_err("No supported pre-processing options\n");
> +		return ret;
> +	}

Instead of a general message, I was thinking of a more specific
one by telling users that the ratio between the two rates isn't
supported -- something similar to what I suggested previously:

	pair_err("Does not support %d (input) > 8.125 * %d (output)\n",
		 outrate, inrate);

Thanks
Nicolin

[PATCH V3 2/2] ASoC: fsl_asrc: Unify the supported input and output rate

[S.j. Wang]

Unify the supported input and output rate, add the
12kHz/24kHz/128kHz to the support list

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
 sound/soc/fsl/fsl_asrc.c | 30 ++++++++++++++++++------------
 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/sound/soc/fsl/fsl_asrc.c b/sound/soc/fsl/fsl_asrc.c
index d34d539d01f2..b0d19b787bb8 100644
--- a/sound/soc/fsl/fsl_asrc.c
+++ b/sound/soc/fsl/fsl_asrc.c
@@ -27,13 +27,14 @@
 	dev_dbg(&asrc_priv->pdev->dev, "Pair %c: " fmt, 'A' + index, ##__VA_ARGS__)
 
 /* Corresponding to process_option */
-static int supported_input_rate[] = {
-	5512, 8000, 11025, 16000, 22050, 32000, 44100, 48000, 64000, 88200,
-	96000, 176400, 192000,
+static unsigned int supported_asrc_rate[] = {
+	5512, 8000, 11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000,
+	64000, 88200, 96000, 128000, 176400, 192000,
 };
 
-static int supported_asrc_rate[] = {
-	8000, 11025, 16000, 22050, 32000, 44100, 48000, 64000, 88200, 96000, 176400, 192000,
+static struct snd_pcm_hw_constraint_list fsl_asrc_rate_constraints = {
+	.count = ARRAY_SIZE(supported_asrc_rate),
+	.list = supported_asrc_rate,
 };
 
 /**
@@ -296,11 +297,11 @@ static int fsl_asrc_config_pair(struct fsl_asrc_pair *pair)
 	ideal = config->inclk == INCLK_NONE;
 
 	/* Validate input and output sample rates */
-	for (in = 0; in < ARRAY_SIZE(supported_input_rate); in++)
-		if (inrate == supported_input_rate[in])
+	for (in = 0; in < ARRAY_SIZE(supported_asrc_rate); in++)
+		if (inrate == supported_asrc_rate[in])
 			break;
 
-	if (in == ARRAY_SIZE(supported_input_rate)) {
+	if (in == ARRAY_SIZE(supported_asrc_rate)) {
 		pair_err("unsupported input sample rate: %dHz\n", inrate);
 		return -EINVAL;
 	}
@@ -493,7 +494,9 @@ static int fsl_asrc_dai_startup(struct snd_pcm_substream *substream,
 		snd_pcm_hw_constraint_step(substream->runtime, 0,
 					   SNDRV_PCM_HW_PARAM_CHANNELS, 2);
 
-	return 0;
+
+	return snd_pcm_hw_constraint_list(substream->runtime, 0,
+			SNDRV_PCM_HW_PARAM_RATE, &fsl_asrc_rate_constraints);
 }
 
 static int fsl_asrc_dai_hw_params(struct snd_pcm_substream *substream,
@@ -606,7 +609,6 @@ static int fsl_asrc_dai_probe(struct snd_soc_dai *dai)
 	return 0;
 }
 
-#define FSL_ASRC_RATES		 SNDRV_PCM_RATE_8000_192000
 #define FSL_ASRC_FORMATS	(SNDRV_PCM_FMTBIT_S24_LE | \
 				 SNDRV_PCM_FMTBIT_S16_LE | \
 				 SNDRV_PCM_FMTBIT_S20_3LE)
@@ -617,14 +619,18 @@ static int fsl_asrc_dai_probe(struct snd_soc_dai *dai)
 		.stream_name = "ASRC-Playback",
 		.channels_min = 1,
 		.channels_max = 10,
-		.rates = FSL_ASRC_RATES,
+		.rate_min = 5512,
+		.rate_max = 192000,
+		.rates = SNDRV_PCM_RATE_KNOT,
 		.formats = FSL_ASRC_FORMATS,
 	},
 	.capture = {
 		.stream_name = "ASRC-Capture",
 		.channels_min = 1,
 		.channels_max = 10,
-		.rates = FSL_ASRC_RATES,
+		.rate_min = 5512,
+		.rate_max = 192000,
+		.rates = SNDRV_PCM_RATE_KNOT,
 		.formats = FSL_ASRC_FORMATS,
 	},
 	.ops = &fsl_asrc_dai_ops,
-- 
1.9.1

Re: [PATCH V3 1/2] ASoC: fsl_asrc: replace the process_option table with function

[S.j. Wang]

Hi

> 
> Hi Shengjiu,
> 
> This looks better. Just a couple of more small comments inline.
> 
> On Wed, Apr 17, 2019 at 09:06:18AM +0000, S.j. Wang wrote:
> 
> > +static int fsl_asrc_sel_proc(int inrate, int outrate, int *pre_proc,
> > +                          int *post_proc)
> 
> Just a nit: it looks better by grouping them two-two.
> 
> static int fsl_asrc_sel_proc(int inrate, int outrate,
>                              int *pre_proc, int *post_proc)
> 
> > +     /* Condition for selection of post-processing */
> > +     post_proc_cond2 = (inrate * 15 > outrate * 16 && outrate < 56000) ||
> > +             (inrate > 56000 && outrate < 56000);
> 
> Could align the indentation:
>         post_proc_cond2 = (inrate * 15 > outrate * 16 && outrate < 56000) ||
>                           (inrate > 56000 && outrate < 56000);
> 
> Here:
> > +     /* Does not support cases: Tsout > 8.125 * Tsin */
> > +     if (inrate * 8 > 65 * outrate)
> > +             return -EINVAL;
> And here:
> > +     ret = fsl_asrc_sel_proc(inrate, outrate, &pre_proc, &post_proc);
> > +     if (ret) {
> > +             pair_err("No supported pre-processing options\n");
> > +             return ret;
> > +     }
> 
> Instead of a general message, I was thinking of a more specific one by
> telling users that the ratio between the two rates isn't supported --
> something similar to what I suggested previously:
> 
>         pair_err("Does not support %d (input) > 8.125 * %d (output)\n",
>                  outrate, inrate);
> 
In fsl_asrc_sel_proc,  we can't call the pair_err for there is no
struct fsl_asrc_pair *pair in the argument. Do you think we need to
add this argument?

> Thanks
> Nicolin

Re: [PATCH V3 1/2] ASoC: fsl_asrc: replace the process_option table with function

[Nicolin Chen]

On Thu, Apr 18, 2019 at 02:37:03AM +0000, S.j. Wang wrote:
> > Here:
> > > +     /* Does not support cases: Tsout > 8.125 * Tsin */
> > > +     if (inrate * 8 > 65 * outrate)

Though it might not matter any more (see my last comments),
it should be "inrate > 8.125 * outrate" in the comments.

> > > +             return -EINVAL;
> > And here:
> > > +     ret = fsl_asrc_sel_proc(inrate, outrate, &pre_proc, &post_proc);
> > > +     if (ret) {
> > > +             pair_err("No supported pre-processing options\n");
> > > +             return ret;
> > > +     }
> > 
> > Instead of a general message, I was thinking of a more specific one by
> > telling users that the ratio between the two rates isn't supported --
> > something similar to what I suggested previously:
> > 
> >         pair_err("Does not support %d (input) > 8.125 * %d (output)\n",
> >                  outrate, inrate);
> > 

> In fsl_asrc_sel_proc,  we can't call the pair_err for there is no
> struct fsl_asrc_pair *pair in the argument. Do you think we need to
> add this argument?

I's thinking of adding it to the top of fsl_asrc_config_pair()
as a part of inrate-outrate-validation, however, I found that
actually we already have a similar check in the early routine:
	if ((outrate > 8000 && outrate < 30000) &&
	    (outrate/inrate > 24 || inrate/outrate > 8)) {
		pair_err("exceed supported ratio range [1/24, 8] for \
			 inrate/outrate: %d/%d\n", inrate, outrate);
		return -EINVAL;
	}

And this is according to IMX6DQRM:
    Limited support for the case when output sampling rates is
    between 8kHz and 30kHz. The limitation is the supported ratio
    (Fsin/Fsout) range as between 1/24 to 8

This should cover your 8.125 condition already, even if having
an outrate range between [8KHz, 30KHz] check, since an outrate
above 30KHz will not have an inrate bigger than 8.125 times of
it, given the maximum input rate is 192KHz.

So I think that we can just drop that 8.125 condition from your
change and there's no need to error out any more.

However, we do need a patch to fix a potential rounding issue:
-	    (outrate/inrate > 24 || inrate/outrate > 8)) {
+	    (outrate > 24 * inrate || inrate > 8 * outrate)) {

Should fix the missing whitespace also. And it will be needed
to send to stable kernel too. Will you help submit a change?

Thanks

Re: [PATCH V3 1/2] ASoC: fsl_asrc: replace the process_option table with function

[S.j. Wang]

Hi

> 
> 
> On Thu, Apr 18, 2019 at 02:37:03AM +0000, S.j. Wang wrote:
> > > Here:
> > > > +     /* Does not support cases: Tsout > 8.125 * Tsin */
> > > > +     if (inrate * 8 > 65 * outrate)
> 
> Though it might not matter any more (see my last comments), it should be
> "inrate > 8.125 * outrate" in the comments.
> 
> > > > +             return -EINVAL;
> > > And here:
> > > > +     ret = fsl_asrc_sel_proc(inrate, outrate, &pre_proc, &post_proc);
> > > > +     if (ret) {
> > > > +             pair_err("No supported pre-processing options\n");
> > > > +             return ret;
> > > > +     }
> > >
> > > Instead of a general message, I was thinking of a more specific one
> > > by telling users that the ratio between the two rates isn't
> > > supported -- something similar to what I suggested previously:
> > >
> > >         pair_err("Does not support %d (input) > 8.125 * %d (output)\n",
> > >                  outrate, inrate);
> > >
> 
> > In fsl_asrc_sel_proc,  we can't call the pair_err for there is no
> > struct fsl_asrc_pair *pair in the argument. Do you think we need to
> > add this argument?
> 
> I's thinking of adding it to the top of fsl_asrc_config_pair() as a part of
> inrate-outrate-validation, however, I found that actually we already have a
> similar check in the early routine:
>         if ((outrate > 8000 && outrate < 30000) &&
>             (outrate/inrate > 24 || inrate/outrate > 8)) {
>                 pair_err("exceed supported ratio range [1/24, 8] for \
>                          inrate/outrate: %d/%d\n", inrate, outrate);
>                 return -EINVAL;
>         }
> 
> And this is according to IMX6DQRM:
>     Limited support for the case when output sampling rates is
>     between 8kHz and 30kHz. The limitation is the supported ratio
>     (Fsin/Fsout) range as between 1/24 to 8
> 
> This should cover your 8.125 condition already, even if having an outrate
> range between [8KHz, 30KHz] check, since an outrate above 30KHz will not
> have an inrate bigger than 8.125 times of it, given the maximum input rate
> is 192KHz.
> 
> So I think that we can just drop that 8.125 condition from your change and
> there's no need to error out any more.
> 
No, if outrate=8kHz,  inrate > 88.2kHz, these cases are not supported. 
This is not covered by

        if ((outrate > 8000 && outrate < 30000) &&
            (outrate/inrate > 24 || inrate/outrate > 8)) {

> However, we do need a patch to fix a potential rounding issue:
> -           (outrate/inrate > 24 || inrate/outrate > 8)) {
> +           (outrate > 24 * inrate || inrate > 8 * outrate)) {
> 
> Should fix the missing whitespace also. And it will be needed to send to
> stable kernel too. Will you help submit a change?
> 
> Thanks

Re: [PATCH V3 1/2] ASoC: fsl_asrc: replace the process_option table with function

[Nicolin Chen]

On Thu, Apr 18, 2019 at 08:50:48AM +0000, S.j. Wang wrote:
> > And this is according to IMX6DQRM:
> >     Limited support for the case when output sampling rates is
> >     between 8kHz and 30kHz. The limitation is the supported ratio
> >     (Fsin/Fsout) range as between 1/24 to 8
> > 
> > This should cover your 8.125 condition already, even if having an outrate
> > range between [8KHz, 30KHz] check, since an outrate above 30KHz will not
> > have an inrate bigger than 8.125 times of it, given the maximum input rate
> > is 192KHz.
> > 
> > So I think that we can just drop that 8.125 condition from your change and
> > there's no need to error out any more.
> > 
> No, if outrate=8kHz,  inrate > 88.2kHz, these cases are not supported. 
> This is not covered by
> 
>         if ((outrate > 8000 && outrate < 30000) &&
>             (outrate/inrate > 24 || inrate/outrate > 8)) {

Good catch. The range should be [8KHz, 30KHz] vs. (8KHz, 32KHz)
in the code. Then I think the fix should be at both lines:

-         if ((outrate > 8000 && outrate < 30000) &&
-             (outrate/inrate > 24 || inrate/outrate > 8)) {
+         if ((outrate >= 8000 && outrate =< 30000) &&
+             (outrate > 24 * inrate || inrate > 8 * outrate)) {

Overall, I think we should fix this instead of adding an extra
one, since it is very likely saying the same thing.

Re: [PATCH V3 1/2] ASoC: fsl_asrc: replace the process_option table with function

[S.j. Wang]

Hi

> 
> On Thu, Apr 18, 2019 at 08:50:48AM +0000, S.j. Wang wrote:
> > > And this is according to IMX6DQRM:
> > >     Limited support for the case when output sampling rates is
> > >     between 8kHz and 30kHz. The limitation is the supported ratio
> > >     (Fsin/Fsout) range as between 1/24 to 8
> > >
> > > This should cover your 8.125 condition already, even if having an
> > > outrate range between [8KHz, 30KHz] check, since an outrate above
> > > 30KHz will not have an inrate bigger than 8.125 times of it, given
> > > the maximum input rate is 192KHz.
> > >
> > > So I think that we can just drop that 8.125 condition from your
> > > change and there's no need to error out any more.
> > >
> > No, if outrate=8kHz,  inrate > 88.2kHz, these cases are not supported.
> > This is not covered by
> >
> >         if ((outrate > 8000 && outrate < 30000) &&
> >             (outrate/inrate > 24 || inrate/outrate > 8)) {
> 
> Good catch. The range should be [8KHz, 30KHz] vs. (8KHz, 32KHz) in the
> code. Then I think the fix should be at both lines:
> 
> -         if ((outrate > 8000 && outrate < 30000) &&
> -             (outrate/inrate > 24 || inrate/outrate > 8)) {
> +         if ((outrate >= 8000 && outrate =< 30000) &&
> +             (outrate > 24 * inrate || inrate > 8 * outrate)) {
> 
> Overall, I think we should fix this instead of adding an extra one, since it is
> very likely saying the same thing.

Actually if outrate < 8kHz, there will be issue too.

Best regards
Wang shengjiu

Re: [PATCH V3 1/2] ASoC: fsl_asrc: replace the process_option table with function

[Nicolin Chen]

On Thu, Apr 18, 2019 at 09:37:06AM +0000, S.j. Wang wrote:
> > > > And this is according to IMX6DQRM:
> > > >     Limited support for the case when output sampling rates is
> > > >     between 8kHz and 30kHz. The limitation is the supported ratio
> > > >     (Fsin/Fsout) range as between 1/24 to 8
> > > >
> > > > This should cover your 8.125 condition already, even if having an
> > > > outrate range between [8KHz, 30KHz] check, since an outrate above
> > > > 30KHz will not have an inrate bigger than 8.125 times of it, given
> > > > the maximum input rate is 192KHz.
> > > >
> > > > So I think that we can just drop that 8.125 condition from your
> > > > change and there's no need to error out any more.
> > > >
> > > No, if outrate=8kHz,  inrate > 88.2kHz, these cases are not supported.
> > > This is not covered by
> > >
> > >         if ((outrate > 8000 && outrate < 30000) &&
> > >             (outrate/inrate > 24 || inrate/outrate > 8)) {
> > 
> > Good catch. The range should be [8KHz, 30KHz] vs. (8KHz, 32KHz) in the
> > code. Then I think the fix should be at both lines:
> > 
> > -         if ((outrate > 8000 && outrate < 30000) &&
> > -             (outrate/inrate > 24 || inrate/outrate > 8)) {
> > +         if ((outrate >= 8000 && outrate =< 30000) &&
> > +             (outrate > 24 * inrate || inrate > 8 * outrate)) {
> > 
> > Overall, I think we should fix this instead of adding an extra one, since it is
> > very likely saying the same thing.
> 
> Actually if outrate < 8kHz, there will be issue too.

Here is the thing, the RM doesn't explicitly state that ASRC can
support a lower output sample rate than 8KHz. And I actually had
a concern when reviewing your PATCH-2, as the table of supported
output sample rate no longer matches RM.

If you've verified a lower output sample rate working solid with
the process_option function, that means our driver can go beyond
the limitation mentioned in the RM, then I believe [8KHz, 32KHz]
should be updated too -- that says we can do:
-	if ((outrate > 8000 && outrate < 30000) &&
-	    (outrate/inrate > 24 || inrate/outrate > 8)) {
+	if ((outrate >= 5512 && outrate =< 30000) &&
+	    (outrate > 24 * inrate || inrate > 8 * outrate)) {

Actually "ourate > 24 * inrate" is kind of pointless for range
[5KHz, 32KHz] but we can keep it since it matches RM.

Re: [PATCH V3 1/2] ASoC: fsl_asrc: replace the process_option table with function

[S.j. Wang]

Hi

> 
> 
> On Thu, Apr 18, 2019 at 09:37:06AM +0000, S.j. Wang wrote:
> > > > > And this is according to IMX6DQRM:
> > > > >     Limited support for the case when output sampling rates is
> > > > >     between 8kHz and 30kHz. The limitation is the supported ratio
> > > > >     (Fsin/Fsout) range as between 1/24 to 8
> > > > >
> > > > > This should cover your 8.125 condition already, even if having
> > > > > an outrate range between [8KHz, 30KHz] check, since an outrate
> > > > > above 30KHz will not have an inrate bigger than 8.125 times of
> > > > > it, given the maximum input rate is 192KHz.
> > > > >
> > > > > So I think that we can just drop that 8.125 condition from your
> > > > > change and there's no need to error out any more.
> > > > >
> > > > No, if outrate=8kHz,  inrate > 88.2kHz, these cases are not supported.
> > > > This is not covered by
> > > >
> > > >         if ((outrate > 8000 && outrate < 30000) &&
> > > >             (outrate/inrate > 24 || inrate/outrate > 8)) {
> > >
> > > Good catch. The range should be [8KHz, 30KHz] vs. (8KHz, 32KHz) in
> > > the code. Then I think the fix should be at both lines:
> > >
> > > -         if ((outrate > 8000 && outrate < 30000) &&
> > > -             (outrate/inrate > 24 || inrate/outrate > 8)) {
> > > +         if ((outrate >= 8000 && outrate =< 30000) &&
> > > +             (outrate > 24 * inrate || inrate > 8 * outrate)) {
> > >
> > > Overall, I think we should fix this instead of adding an extra one,
> > > since it is very likely saying the same thing.
> >
> > Actually if outrate < 8kHz, there will be issue too.
> 
> Here is the thing, the RM doesn't explicitly state that ASRC can support a
> lower output sample rate than 8KHz. And I actually had a concern when
> reviewing your PATCH-2, as the table of supported output sample rate no
> longer matches RM.
> 
> If you've verified a lower output sample rate working solid with the
> process_option function, that means our driver can go beyond the
> limitation mentioned in the RM, then I believe [8KHz, 32KHz] should be
> updated too -- that says we can do:
> -       if ((outrate > 8000 && outrate < 30000) &&
> -           (outrate/inrate > 24 || inrate/outrate > 8)) {
> +       if ((outrate >= 5512 && outrate =< 30000) &&
> +           (outrate > 24 * inrate || inrate > 8 * outrate)) {
> 
> Actually "ourate > 24 * inrate" is kind of pointless for range [5KHz, 32KHz]
> but we can keep it since it matches RM.

Ok, will send v4.

Best regards
Wang shengjiu