[PATCH 05/15] ASoC: rockchip: i2s: Fix concurrency between tx/rx

[Sugar Zhang <sugar.zhang@rock-chips.com>]

This patch adds lock to fix comcurrency between tx/rx
to fix 'rockchip-i2s ff070000.i2s; fail to clear'

Considering the situation;

       tx stream              rx stream
           |                      |
           |                   disable
         enable                   |
           |                    reset

After this patch:

         lock
           |
       tx stream
           |
         enable
           |
        unlock
       --------               ---------
                                lock
                                  |
                              rx stream
                                  |
                               disable
                                  |
                                reset
                                  |
                               unlock

Change-Id: Ia156144490a61f4fa9823b1313588e44688f4bce
Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
---
 sound/soc/rockchip/rockchip_i2s.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/sound/soc/rockchip/rockchip_i2s.c b/sound/soc/rockchip/rockchip_i2s.c
index dfa0a5e..b8e35a9 100644
--- a/sound/soc/rockchip/rockchip_i2s.c
+++ b/sound/soc/rockchip/rockchip_i2s.c
@@ -15,6 +15,7 @@
 #include <linux/clk.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
+#include <linux/spinlock.h>
 #include <sound/pcm_params.h>
 #include <sound/dmaengine_pcm.h>
 
@@ -52,6 +53,9 @@ struct rk_i2s_dev {
 	unsigned int bclk_ratio;
 };
 
+/* tx/rx ctrl lock */
+static DEFINE_SPINLOCK(lock);
+
 static int i2s_runtime_suspend(struct device *dev)
 {
 	struct rk_i2s_dev *i2s = dev_get_drvdata(dev);
@@ -93,6 +97,7 @@ static void rockchip_snd_txctrl(struct rk_i2s_dev *i2s, int on)
 	unsigned int val = 0;
 	int retry = 10;
 
+	spin_lock(&lock);
 	if (on) {
 		regmap_update_bits(i2s->regmap, I2S_DMACR,
 				   I2S_DMACR_TDE_ENABLE, I2S_DMACR_TDE_ENABLE);
@@ -133,6 +138,7 @@ static void rockchip_snd_txctrl(struct rk_i2s_dev *i2s, int on)
 			}
 		}
 	}
+	spin_unlock(&lock);
 }
 
 static void rockchip_snd_rxctrl(struct rk_i2s_dev *i2s, int on)
@@ -140,6 +146,7 @@ static void rockchip_snd_rxctrl(struct rk_i2s_dev *i2s, int on)
 	unsigned int val = 0;
 	int retry = 10;
 
+	spin_lock(&lock);
 	if (on) {
 		regmap_update_bits(i2s->regmap, I2S_DMACR,
 				   I2S_DMACR_RDE_ENABLE, I2S_DMACR_RDE_ENABLE);
@@ -180,6 +187,7 @@ static void rockchip_snd_rxctrl(struct rk_i2s_dev *i2s, int on)
 			}
 		}
 	}
+	spin_unlock(&lock);
 }
 
 static int rockchip_i2s_set_fmt(struct snd_soc_dai *cpu_dai,
-- 
2.7.4