struct regmap *regmap;
 
+/*
+ * Used to indicate the tx/rx status.
+ * I2S controller hopes to start the tx and rx together,
+ * also to stop them when they are both try to stop.
+*/
+       bool tx_start;
+       bool rx_start;
        bool is_master_mode;
 };
 
                regmap_update_bits(i2s->regmap, I2S_XFER,
                                   I2S_XFER_TXS_START,
                                   I2S_XFER_TXS_START);
+
+               i2s->tx_start = true;
        } else {
+               i2s->tx_start = false;
+
                regmap_update_bits(i2s->regmap, I2S_DMACR,
                                   I2S_DMACR_TDE_ENABLE, I2S_DMACR_TDE_DISABLE);
 
                regmap_update_bits(i2s->regmap, I2S_XFER,
                                   I2S_XFER_RXS_START,
                                   I2S_XFER_RXS_START);
+
+               i2s->rx_start = true;
        } else {
+               i2s->rx_start = false;
+
                regmap_update_bits(i2s->regmap, I2S_DMACR,
                                   I2S_DMACR_RDE_ENABLE, I2S_DMACR_RDE_DISABLE);