linux-kernel - [PATCH 16/22] ASoC: samsung: i2s: Get rid of a static spinlock

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Date:   Thu, 07 Feb 2019 18:00:24 +0100
From:   Sylwester Nawrocki <s.nawrocki@...sung.com>
To:     broonie@...nel.org
Cc:     lgirdwood@...il.com, krzk@...nel.org, sbkim73@...sung.com,
        m.szyprowski@...sung.com, b.zolnierkie@...sung.com,
        alsa-devel@...a-project.org, linux-kernel@...r.kernel.org,
        linux-samsung-soc@...r.kernel.org,
        Sylwester Nawrocki <s.nawrocki@...sung.com>
Subject: [PATCH 16/22] ASoC: samsung: i2s: Get rid of a static spinlock

This patch makes the spinlock serializing access to the primary/secondary
PCM a per I2S controller lock, rather than a global one. There is no need
to have a global lock across multiple I2S controllers in the SoC.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@...sung.com>
---
 sound/soc/samsung/i2s.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/sound/soc/samsung/i2s.c b/sound/soc/samsung/i2s.c
index e11d678e9c1f..9931d007bc13 100644
--- a/sound/soc/samsung/i2s.c
+++ b/sound/soc/samsung/i2s.c
@@ -88,9 +88,6 @@ struct i2s_dai {
 	struct samsung_i2s_priv *priv;
 };
 
-/* Lock for cross i/f checks */
-static DEFINE_SPINLOCK(lock);
-
 struct samsung_i2s_priv {
 	struct platform_device *pdev;
 	struct platform_device *pdev_sec;
@@ -101,6 +98,9 @@ struct samsung_i2s_priv {
 	/* Spinlock protecting access to the device's registers */
 	spinlock_t lock;
 
+	/* Lock for cross i/f checks */
+	spinlock_t pcm_lock;
+
 	/* CPU DAIs and their corresponding drivers */
 	struct i2s_dai *dai;
 	struct snd_soc_dai_driver *dai_drv;
@@ -832,7 +832,7 @@ static int i2s_startup(struct snd_pcm_substream *substream,
 
 	pm_runtime_get_sync(dai->dev);
 
-	spin_lock_irqsave(&lock, flags);
+	spin_lock_irqsave(&priv->pcm_lock, flags);
 
 	i2s->mode |= DAI_OPENED;
 
@@ -844,7 +844,7 @@ static int i2s_startup(struct snd_pcm_substream *substream,
 	if (!any_active(i2s) && (priv->quirks & QUIRK_NEED_RSTCLR))
 		writel(CON_RSTCLR, i2s->priv->addr + I2SCON);
 
-	spin_unlock_irqrestore(&lock, flags);
+	spin_unlock_irqrestore(&priv->pcm_lock, flags);
 
 	return 0;
 }
@@ -852,11 +852,12 @@ static int i2s_startup(struct snd_pcm_substream *substream,
 static void i2s_shutdown(struct snd_pcm_substream *substream,
 	struct snd_soc_dai *dai)
 {
+	struct samsung_i2s_priv *priv = snd_soc_dai_get_drvdata(dai);
 	struct i2s_dai *i2s = to_info(dai);
 	struct i2s_dai *other = get_other_dai(i2s);
 	unsigned long flags;
 
-	spin_lock_irqsave(&lock, flags);
+	spin_lock_irqsave(&priv->pcm_lock, flags);
 
 	i2s->mode &= ~DAI_OPENED;
 	i2s->mode &= ~DAI_MANAGER;
@@ -868,7 +869,7 @@ static void i2s_shutdown(struct snd_pcm_substream *substream,
 	i2s->rfs = 0;
 	i2s->bfs = 0;
 
-	spin_unlock_irqrestore(&lock, flags);
+	spin_unlock_irqrestore(&priv->pcm_lock, flags);
 
 	pm_runtime_put(dai->dev);
 }
@@ -1406,6 +1407,7 @@ static int samsung_i2s_probe(struct platform_device *pdev)
 	pri_dai = &priv->dai[SAMSUNG_I2S_ID_PRIMARY - 1];
 
 	spin_lock_init(&priv->lock);
+	spin_lock_init(&priv->pcm_lock);
 
 	if (!np) {
 		if (i2s_pdata == NULL) {
-- 
2.20.1