ASoC: rsnd: don't fallback to PIO mode when -EPROBE_DEFER

Current rsnd driver will fallback to PIO mode if it can't get DMA
handler. But, DMA might return -EPROBE_DEFER when probe timing.
This driver always fallback to PIO mode especially from
commit ac6bbf0cdf4206c ("iommu: Remove IOMMU_OF_DECLARE") because
of this reason.

The DMA driver will be probed later, but sound driver might be
probed as PIO mode in such case. This patch fixup this issue.
Then, -EPROBE_DEFER is not error. Thus, let's don't indicate error
message in such case.
And it needs to call rsnd_adg_remove() individually if probe failed,
because it registers clk which should be unregister.

Maybe PIO fallback feature itself is not needed,
but let's keep it so far.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sh/rcar/core.c

@@ -478,7 +478,7 @@ static int rsnd_status_update(u32 *status,
 			(func_call && (mod)->ops->fn) ? #fn : "");	\
 		if (func_call && (mod)->ops->fn)			\
 			tmp = (mod)->ops->fn(mod, io, param);		\
-		if (tmp)						\
+		if (tmp && (tmp != -EPROBE_DEFER))			\
 			dev_err(dev, "%s[%d] : %s error %d\n",		\
 				rsnd_mod_name(mod), rsnd_mod_id(mod),	\
 						     #fn, tmp);		\
@@ -1561,6 +1561,14 @@ exit_snd_probe:
 		rsnd_dai_call(remove, &rdai->capture, priv);
 	}
 
+	/*
+	 * adg is very special mod which can't use rsnd_dai_call(remove),
+	 * and it registers ADG clock on probe.
+	 * It should be unregister if probe failed.
+	 * Mainly it is assuming -EPROBE_DEFER case
+	 */
+	rsnd_adg_remove(priv);
+
 	return ret;
 }
 

sound/soc/sh/rcar/dma.c

@@ -241,6 +241,10 @@ static int rsnd_dmaen_attach(struct rsnd_dai_stream *io,
 	/* try to get DMAEngine channel */
 	chan = rsnd_dmaen_request_channel(io, mod_from, mod_to);
 	if (IS_ERR_OR_NULL(chan)) {
+		/* Let's follow when -EPROBE_DEFER case */
+		if (PTR_ERR(chan) == -EPROBE_DEFER)
+			return PTR_ERR(chan);
+
 		/*
 		 * DMA failed. try to PIO mode
 		 * see