Re: [PATCH v1 2/3] ASoC: rsnd: Allow reconfiguration of clock rate

[Kuninori Morimoto]

Hi Jiada, again

> The solution looks very over-kill to me,
> especiallyq [3/3] patch is too much to me.
> 
> 1st, can we start clock at .hw_param, instead of .prepare ?
> and stop it at .hw_free ?
> 
> 2nd, can we keep usrcnt setup as-is ?
> I guess we can just avoid rsnd_ssi_master_clk_start() if ssi->rate was not 0 ?
> similar for rsnd_ssi_master_clk_stop()

In my quick check, I used your [1/3] patch and below.
It works for me, but I don't know detail of your test case.

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diff --git a/sound/soc/sh/rcar/ssi.c b/sound/soc/sh/rcar/ssi.c
index f6a7466..f26ffd1 100644
--- a/sound/soc/sh/rcar/ssi.c
+++ b/sound/soc/sh/rcar/ssi.c
@@ -286,19 +286,8 @@ static int rsnd_ssi_master_clk_start(struct rsnd_mod *mod,
        if (rsnd_ssi_is_multi_slave(mod, io))
                return 0;
 
-       if (ssi->usrcnt > 0) {
-               if (ssi->rate != rate) {
-                       dev_err(dev, "SSI parent/child should use same rate\n");
-                       return -EINVAL;
-               }
-
-               if (ssi->chan != chan) {
-                       dev_err(dev, "SSI parent/child should use same chan\n");
-                       return -EINVAL;
-               }
-
+       if (ssi->rate)
                return 0;
-       }
 
        if (rsnd_runtime_is_tdm_split(io))
                chan = rsnd_io_converted_chan(io);
@@ -349,7 +338,7 @@ static void rsnd_ssi_master_clk_stop(struct rsnd_mod *mod,
        if (!rsnd_ssi_can_output_clk(mod))
                return;
 
-       if (ssi->usrcnt > 1)
+       if (!ssi->rate)
                return;
 
        ssi->cr_clk     = 0;
@@ -539,6 +528,17 @@ static int rsnd_ssi_hw_params(struct rsnd_mod *mod,
        return 0;
 }
 
+static int rsnd_ssi_hw_free(struct rsnd_mod *mod, struct rsnd_dai_stream *io,
+                           struct snd_pcm_substream *substream)
+{
+       if (!rsnd_ssi_is_run_mods(mod, io))
+               return 0;
+
+       rsnd_ssi_master_clk_stop(mod, io);
+
+       return 0;
+}
+
 static int rsnd_ssi_start(struct rsnd_mod *mod,
                          struct rsnd_dai_stream *io,
                          struct rsnd_priv *priv)
@@ -925,6 +925,7 @@ static struct rsnd_mod_ops rsnd_ssi_pio_ops = {
        .pointer        = rsnd_ssi_pio_pointer,
        .pcm_new        = rsnd_ssi_pcm_new,
        .hw_params      = rsnd_ssi_hw_params,
+       .hw_free        = rsnd_ssi_hw_free,
        .prepare        = rsnd_ssi_prepare,
        .get_status     = rsnd_ssi_get_status,
 };
@@ -1012,6 +1013,7 @@ static struct rsnd_mod_ops rsnd_ssi_dma_ops = {
        .pcm_new        = rsnd_ssi_pcm_new,
        .fallback       = rsnd_ssi_fallback,
        .hw_params      = rsnd_ssi_hw_params,
+       .hw_free        = rsnd_ssi_hw_free,
        .prepare        = rsnd_ssi_prepare,
        .get_status     = rsnd_ssi_get_status,
 };
----------