[PATCH 4/6] ASoC: hdmi-codec: remove reference to the current substream

From: Jerome Brunet
Date: Mon Apr 29 2019 - 09:30:07 EST


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@xxxxxxxxxxxx>
---
sound/soc/codecs/hdmi-codec.c | 58 ++++++++++-------------------------
1 file changed, 16 insertions(+), 42 deletions(-)

diff --git a/sound/soc/codecs/hdmi-codec.c b/sound/soc/codecs/hdmi-codec.c
index 780f2008b271..717d0949f8b4 100644
--- 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,
@@ -766,8 +742,6 @@ 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)
--
2.20.1