ASoC: hdmi-codec: remove reference to the current substream

If the hdmi-codec is on a codec-to-codec link, the substream pointer
it receives is completely made up by snd_soc_dai_link_event().
The pointer will be different between startup() and shutdown().

The hdmi-codec complains when this happens even if it is not really a
problem. The current_substream pointer is not used for anything useful
apart from getting the exclusive ownership of the device.

Remove current_substream pointer and replace the exclusive locking
mechanism with a simple variable and some atomic operations.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/codecs/hdmi-codec.c b/sound/soc/codecs/hdmi-codec.c
index eb31d7e..4d32f93 100644 (file)
--- a/sound/soc/codecs/hdmi-codec.c
+++ b/sound/soc/codecs/hdmi-codec.c
@@ -280,11 +280,10 @@ struct hdmi_codec_priv {
        struct hdmi_codec_pdata hcd;
        struct snd_soc_dai_driver *daidrv;
        struct hdmi_codec_daifmt daifmt[2];
-       struct mutex current_stream_lock;
-       struct snd_pcm_substream *current_stream;
        uint8_t eld[MAX_ELD_BYTES];
        struct snd_pcm_chmap *chmap_info;
        unsigned int chmap_idx;
+       unsigned long busy;
 };
 
 static const struct snd_soc_dapm_widget hdmi_widgets[] = {
@@ -392,42 +391,22 @@ static int hdmi_codec_chmap_ctl_get(struct snd_kcontrol *kcontrol,
        return 0;
 }
 
-static int hdmi_codec_new_stream(struct snd_pcm_substream *substream,
-                                struct snd_soc_dai *dai)
-{
-       struct hdmi_codec_priv *hcp = snd_soc_dai_get_drvdata(dai);
-       int ret = 0;
-
-       mutex_lock(&hcp->current_stream_lock);
-       if (!hcp->current_stream) {
-               hcp->current_stream = substream;
-       } else if (hcp->current_stream != substream) {
-               dev_err(dai->dev, "Only one simultaneous stream supported!\n");
-               ret = -EINVAL;
-       }
-       mutex_unlock(&hcp->current_stream_lock);
-
-       return ret;
-}
-
 static int hdmi_codec_startup(struct snd_pcm_substream *substream,
                              struct snd_soc_dai *dai)
 {
        struct hdmi_codec_priv *hcp = snd_soc_dai_get_drvdata(dai);
        int ret = 0;
 
-       ret = hdmi_codec_new_stream(substream, dai);
-       if (ret)
-               return ret;
+       ret = test_and_set_bit(0, &hcp->busy);
+       if (ret) {
+               dev_err(dai->dev, "Only one simultaneous stream supported!\n");
+               return -EINVAL;
+       }
 
        if (hcp->hcd.ops->audio_startup) {
                ret = hcp->hcd.ops->audio_startup(dai->dev->parent, hcp->hcd.data);
-               if (ret) {
-                       mutex_lock(&hcp->current_stream_lock);
-                       hcp->current_stream = NULL;
-                       mutex_unlock(&hcp->current_stream_lock);
-                       return ret;
-               }
+               if (ret)
+                       goto err;
        }
 
        if (hcp->hcd.ops->get_eld) {
@@ -437,17 +416,18 @@ static int hdmi_codec_startup(struct snd_pcm_substream *substream,
                if (!ret) {
                        ret = snd_pcm_hw_constraint_eld(substream->runtime,
                                                        hcp->eld);
-                       if (ret) {
-                               mutex_lock(&hcp->current_stream_lock);
-                               hcp->current_stream = NULL;
-                               mutex_unlock(&hcp->current_stream_lock);
-                               return ret;
-                       }
+                       if (ret)
+                               goto err;
                }
                /* Select chmap supported */
                hdmi_codec_eld_chmap(hcp);
        }
        return 0;
+
+err:
+       /* Release the exclusive lock on error */
+       clear_bit(0, &hcp->busy);
+       return ret;
 }
 
 static void hdmi_codec_shutdown(struct snd_pcm_substream *substream,
@@ -455,14 +435,10 @@ static void hdmi_codec_shutdown(struct snd_pcm_substream *substream,
 {
        struct hdmi_codec_priv *hcp = snd_soc_dai_get_drvdata(dai);
 
-       WARN_ON(hcp->current_stream != substream);
-
        hcp->chmap_idx = HDMI_CODEC_CHMAP_IDX_UNKNOWN;
        hcp->hcd.ops->audio_shutdown(dai->dev->parent, hcp->hcd.data);
 
-       mutex_lock(&hcp->current_stream_lock);
-       hcp->current_stream = NULL;
-       mutex_unlock(&hcp->current_stream_lock);
+       clear_bit(0, &hcp->busy);
 }
 
 static int hdmi_codec_hw_params(struct snd_pcm_substream *substream,
@@ -761,8 +737,6 @@ static int hdmi_codec_probe(struct platform_device *pdev)
                return -ENOMEM;
 
        hcp->hcd = *hcd;
-       mutex_init(&hcp->current_stream_lock);
-
        hcp->daidrv = devm_kcalloc(dev, dai_count, sizeof(*hcp->daidrv),
                                   GFP_KERNEL);
        if (!hcp->daidrv)