[ARM] tegra: tegra_i2s_audio: do not reset the i2s fifo unnecessarily

This patch removes redundant i2s fifo resets, which also cause blips on playback.
It also moves the fifo attention levels to struct audio_stream.

Signed-off-by: Iliyan Malchev <malchev@google.com>

diff --git a/arch/arm/mach-tegra/tegra_i2s_audio.c b/arch/arm/mach-tegra/tegra_i2s_audio.c
index 47626e103e8d44545ce21810704a42907a7bc91d..04f947793201d8ea759e9566990cb15cc6eccb67 100644 (file)
--- a/arch/arm/mach-tegra/tegra_i2s_audio.c
+++ b/arch/arm/mach-tegra/tegra_i2s_audio.c
@@ -64,6 +64,8 @@ struct audio_stream {
 
        unsigned errors;
 
+       int i2s_fifo_atn_level;
+
        ktime_t last_dma_ts;
        struct tegra_dma_channel *dma_chan;
        struct completion stop_completion;
@@ -810,6 +812,12 @@ static int resume_dma_playback(struct audio_stream *aos)
                return 0;
        }
 
+#if 0
+       i2s_fifo_clear(ads->i2s_base, I2S_FIFO_TX);
+#endif
+       i2s_fifo_set_attention_level(ads->i2s_base,
+                       I2S_FIFO_TX, aos->i2s_fifo_atn_level);
+
        req->source_addr = aos->buf_phys + out;
        if (out < in)
                req->size = in - out;
@@ -825,8 +833,6 @@ static int resume_dma_playback(struct audio_stream *aos)
        pr_debug("%s resume playback (%d in fifo, writing %d, in %d out %d)\n",
                        __func__, kfifo_len(&aos->fifo), req->size, in, out);
 
-       i2s_fifo_set_attention_level(ads->i2s_base,
-                       I2S_FIFO_TX, I2S_FIFO_ATN_LVL_FOUR_SLOTS);
        i2s_fifo_enable(ads->i2s_base, I2S_FIFO_TX, 1);
 
        aos->last_dma_ts = ktime_get_real();
@@ -906,9 +912,11 @@ static int resume_dma_recording(struct audio_stream *ais)
                return -EINVAL;
        }
 
+#if 0
        i2s_fifo_clear(ads->i2s_base, I2S_FIFO_RX);
+#endif
        i2s_fifo_set_attention_level(ads->i2s_base,
-                       I2S_FIFO_RX, I2S_FIFO_ATN_LVL_TWELVE_SLOTS);
+                       I2S_FIFO_RX, ais->i2s_fifo_atn_level);
        i2s_fifo_enable(ads->i2s_base, I2S_FIFO_RX, 1);
        return 0;
 }
@@ -963,8 +971,10 @@ static int start_pio_playback(struct audio_stream *aos)
        pr_debug("%s\n", __func__);
 
        i2s_fifo_set_attention_level(ads->i2s_base,
-                       I2S_FIFO_TX, I2S_FIFO_ATN_LVL_ONE_SLOT);
+                       I2S_FIFO_TX, aos->i2s_fifo_atn_level);
+#if 0
        i2s_fifo_clear(ads->i2s_base, I2S_FIFO_TX);
+#endif
 
        i2s_set_fifo_irq_on_err(ads->i2s_base, I2S_FIFO_TX, 1);
        i2s_set_fifo_irq_on_qe(ads->i2s_base, I2S_FIFO_TX, 1);
@@ -1005,8 +1015,10 @@ static int start_pio_recording(struct audio_stream *ais)
        pr_debug("%s: start\n", __func__);
 
        i2s_fifo_set_attention_level(ads->i2s_base,
-                       I2S_FIFO_RX, I2S_FIFO_ATN_LVL_TWELVE_SLOTS);
+                       I2S_FIFO_RX, ais->i2s_fifo_atn_level);
+#if 0
        i2s_fifo_clear(ads->i2s_base, I2S_FIFO_RX);
+#endif
 
        i2s_set_fifo_irq_on_err(ads->i2s_base, I2S_FIFO_RX, 1);
        i2s_set_fifo_irq_on_qe(ads->i2s_base, I2S_FIFO_RX, 1);
@@ -1980,6 +1992,9 @@ static int tegra_audio_probe(struct platform_device *pdev)
                return -EIO;
        }
 
+       state->out.i2s_fifo_atn_level = I2S_FIFO_ATN_LVL_FOUR_SLOTS;
+       state->in.i2s_fifo_atn_level = I2S_FIFO_ATN_LVL_FOUR_SLOTS;
+
        res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
        if (!res) {
                dev_err(&pdev->dev, "no dma resource!\n");
@@ -2024,6 +2039,8 @@ static int tegra_audio_probe(struct platform_device *pdev)
        clk_enable(audio_sync_clk);
 
        /* disable interrupts from I2S */
+       i2s_fifo_clear(state->i2s_base, I2S_FIFO_TX);
+       i2s_fifo_clear(state->i2s_base, I2S_FIFO_RX);
        i2s_enable_fifos(state->i2s_base, 0);
 
        i2s_set_left_right_control_polarity(state->i2s_base, 0); /* default */