ASoC: Intel: Skylake: Reconfigure HDA stream register in prepare/resume

PCM prepare callbacks can be called multiple times. During S3
the stream registers will be reset when Controller is reset.
When stream is resumed, these stream registers needs to reconfigured.

This patch removes the check in prepare callback() if stream already
prepared, which will allow reconfiguring of stream registers and also
decouple stream when stream is resumed to route audio via DSP.
Signed-off-by: Jeeja KP <jeeja.kp@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/skylake/skl-pcm.c

@@ -181,10 +181,6 @@ static int skl_pcm_prepare(struct snd_pcm_substream *substream,
 	int err;
 
 	dev_dbg(dai->dev, "%s: %s\n", __func__, dai->name);
-	if (hdac_stream(stream)->prepared) {
-		dev_dbg(dai->dev, "already stream is prepared - returning\n");
-		return 0;
-	}
 
 	format_val = skl_get_format(substream, dai);
 	dev_dbg(dai->dev, "stream_tag=%d formatvalue=%d\n",
@@ -342,6 +338,8 @@ static int skl_pcm_trigger(struct snd_pcm_substream *substream, int cmd,
 	struct skl *skl = get_skl_ctx(dai->dev);
 	struct skl_sst *ctx = skl->skl_sst;
 	struct skl_module_cfg *mconfig;
+	struct hdac_ext_bus *ebus = get_bus_ctx(substream);
+	struct hdac_ext_stream *stream = get_hdac_ext_stream(substream);
 	int ret;
 
 	mconfig = skl_tplg_fe_get_cpr_module(dai, substream->stream);
@@ -349,15 +347,17 @@ static int skl_pcm_trigger(struct snd_pcm_substream *substream, int cmd,
 		return -EIO;
 
 	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_RESUME:
+		skl_pcm_prepare(substream, dai);
 	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
-	case SNDRV_PCM_TRIGGER_RESUME:
 		/*
 		 * Start HOST DMA and Start FE Pipe.This is to make sure that
 		 * there are no underrun/overrun in the case when the FE
 		 * pipeline is started but there is a delay in starting the
 		 * DMA channel on the host.
 		 */
+		snd_hdac_ext_stream_decouple(ebus, stream, true);
 		ret = skl_decoupled_trigger(substream, cmd);
 		if (ret < 0)
 			return ret;
@@ -377,6 +377,8 @@ static int skl_pcm_trigger(struct snd_pcm_substream *substream, int cmd,
 			return ret;
 
 		ret = skl_decoupled_trigger(substream, cmd);
+		if (cmd == SNDRV_PCM_TRIGGER_SUSPEND)
+			snd_hdac_ext_stream_decouple(ebus, stream, false);
 		break;
 
 	default: