4 files changed, 40 insertions, 22 deletions

diff --git a/include/sound/soc-dai.h b/include/sound/soc-dai.h
index b0ee6590b8ba..800c101bb096 100644
--- a/include/sound/soc-dai.h
+++ b/include/sound/soc-dai.h
@@ -169,6 +169,13 @@ struct snd_soc_dai_ops {
                 struct snd_soc_dai *);
         int (*prepare)(struct snd_pcm_substream *,
                 struct snd_soc_dai *);
+        /*
+         * NOTE: Commands passed to the trigger function are not necessarily
+         * compatible with the current state of the dai. For example this
+         * sequence of commands is possible: START STOP STOP.
+         * So do not unconditionally use refcounting functions in the trigger
+         * function, e.g. clk_enable/disable.
+         */
         int (*trigger)(struct snd_pcm_substream *, int,
                 struct snd_soc_dai *);
         int (*bespoke_trigger)(struct snd_pcm_substream *, int,
diff --git a/sound/soc/mxs/mxs-saif.c b/sound/soc/mxs/mxs-saif.c
index 14152f6f70dd..54e622acac33 100644
--- a/sound/soc/mxs/mxs-saif.c
+++ b/sound/soc/mxs/mxs-saif.c
@@ -494,6 +494,7 @@ static int mxs_saif_trigger(struct snd_pcm_substream *substream, int cmd,
         struct mxs_saif *saif = snd_soc_dai_get_drvdata(cpu_dai);
         struct mxs_saif *master_saif;
         u32 delay;
+        int ret;
 
         master_saif = mxs_saif_get_master(saif);
         if (!master_saif)
@@ -503,23 +504,37 @@ static int mxs_saif_trigger(struct snd_pcm_substream *substream, int cmd,
         case SNDRV_PCM_TRIGGER_START:
         case SNDRV_PCM_TRIGGER_RESUME:
         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+                if (saif->state == MXS_SAIF_STATE_RUNNING)
+                        return 0;
+
                 dev_dbg(cpu_dai->dev, "start\n");
 
-                clk_enable(master_saif->clk);
-                if (!master_saif->mclk_in_use)
-                        __raw_writel(BM_SAIF_CTRL_RUN,
-                                master_saif->base + SAIF_CTRL + MXS_SET_ADDR);
+                ret = clk_enable(master_saif->clk);
+                if (ret) {
+                        dev_err(saif->dev, "Failed to enable master clock\n");
+                        return ret;
+                }
 
                 /*
                  * If the saif's master is not himself, we also need to enable
                  * itself clk for its internal basic logic to work.
                  */
                 if (saif != master_saif) {
-                        clk_enable(saif->clk);
+                        ret = clk_enable(saif->clk);
+                        if (ret) {
+                                dev_err(saif->dev, "Failed to enable master clock\n");
+                                clk_disable(master_saif->clk);
+                                return ret;
+                        }
+
                         __raw_writel(BM_SAIF_CTRL_RUN,
                                 saif->base + SAIF_CTRL + MXS_SET_ADDR);
                 }
 
+                if (!master_saif->mclk_in_use)
+                        __raw_writel(BM_SAIF_CTRL_RUN,
+                                master_saif->base + SAIF_CTRL + MXS_SET_ADDR);
+
                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                         /*
                          * write data to saif data register to trigger
@@ -543,6 +558,7 @@ static int mxs_saif_trigger(struct snd_pcm_substream *substream, int cmd,
                 }
 
                 master_saif->ongoing = 1;
+                saif->state = MXS_SAIF_STATE_RUNNING;
 
                 dev_dbg(saif->dev, "CTRL 0x%x STAT 0x%x\n",
                         __raw_readl(saif->base + SAIF_CTRL),
@@ -555,6 +571,9 @@ static int mxs_saif_trigger(struct snd_pcm_substream *substream, int cmd,
         case SNDRV_PCM_TRIGGER_SUSPEND:
         case SNDRV_PCM_TRIGGER_STOP:
         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+                if (saif->state == MXS_SAIF_STATE_STOPPED)
+                        return 0;
+
                 dev_dbg(cpu_dai->dev, "stop\n");
 
                 /* wait a while for the current sample to complete */
@@ -575,6 +594,7 @@ static int mxs_saif_trigger(struct snd_pcm_substream *substream, int cmd,
                 }
 
                 master_saif->ongoing = 0;
+                saif->state = MXS_SAIF_STATE_STOPPED;
 
                 break;
         default:
diff --git a/sound/soc/mxs/mxs-saif.h b/sound/soc/mxs/mxs-saif.h
index 53eaa4bf0e27..fbaf7badfdfb 100644
--- a/sound/soc/mxs/mxs-saif.h
+++ b/sound/soc/mxs/mxs-saif.h
@@ -124,6 +124,11 @@ struct mxs_saif {
 
         u32 fifo_underrun;
         u32 fifo_overrun;
+
+        enum {
+                MXS_SAIF_STATE_STOPPED,
+                MXS_SAIF_STATE_RUNNING,
+        } state;
 };
 
 extern int mxs_saif_put_mclk(unsigned int saif_id);
diff --git a/sound/soc/mxs/mxs-sgtl5000.c b/sound/soc/mxs/mxs-sgtl5000.c
index 4bb273786ff3..61822cc53bd3 100644
--- a/sound/soc/mxs/mxs-sgtl5000.c
+++ b/sound/soc/mxs/mxs-sgtl5000.c
@@ -122,14 +122,12 @@ static struct snd_soc_card mxs_sgtl5000 = {
         .num_links      = ARRAY_SIZE(mxs_sgtl5000_dai),
 };
 
-static int mxs_sgtl5000_probe_dt(struct platform_device *pdev)
+static int mxs_sgtl5000_probe(struct platform_device *pdev)
 {
+        struct snd_soc_card *card = &mxs_sgtl5000;
+        int ret, i;
         struct device_node *np = pdev->dev.of_node;
         struct device_node *saif_np[2], *codec_np;
-        int i;
-
-        if (!np)
-                return 1; /* no device tree */
 
         saif_np[0] = of_parse_phandle(np, "saif-controllers", 0);
         saif_np[1] = of_parse_phandle(np, "saif-controllers", 1);
@@ -152,18 +150,6 @@ static int mxs_sgtl5000_probe_dt(struct platform_device *pdev)
         of_node_put(saif_np[0]);
         of_node_put(saif_np[1]);
 
-        return 0;
-}
-
-static int mxs_sgtl5000_probe(struct platform_device *pdev)
-{
-        struct snd_soc_card *card = &mxs_sgtl5000;
-        int ret;
-
-        ret = mxs_sgtl5000_probe_dt(pdev);
-        if (ret < 0)
-                return ret;
-
         /*
          * Set an init clock(11.28Mhz) for sgtl5000 initialization(i2c r/w).
          * The Sgtl5000 sysclk is derived from saif0 mclk and it's range