[alsa-devel] [PATCH 3/3 v3] ASoC: dwc: Unmask I2S interrupts only for enabled channels

[Jose Abreu]

There is no need to unmask all interrupts at I2S start. This
can cause performance issues in slower platforms.

Unmask only the interrupts for the used channels.

Signed-off-by: Jose Abreu <joabreu at synopsys.com>
---

Changes v2 -> v3:
* Dropped custom platform driver, using now ALSA DMA engine
* Dropped IRQ handler for I2S
* Removed pll_config functions (as suggested by Alexey Brodkin)

No changes v1 -> v2.

 sound/soc/dwc/designware_i2s.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/sound/soc/dwc/designware_i2s.c b/sound/soc/dwc/designware_i2s.c
index bff258d..3effcd1 100644
--- a/sound/soc/dwc/designware_i2s.c
+++ b/sound/soc/dwc/designware_i2s.c
@@ -147,17 +147,18 @@ static inline void i2s_clear_irqs(struct dw_i2s_dev *dev, u32 stream)
 static void i2s_start(struct dw_i2s_dev *dev,
 		      struct snd_pcm_substream *substream)
 {
+	struct i2s_clk_config_data *config = &dev->config;
 	u32 i, irq;
 	i2s_write_reg(dev->i2s_base, IER, 1);
 
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
-		for (i = 0; i < 4; i++) {
+		for (i = 0; i < (config->chan_nr / 2); i++) {
 			irq = i2s_read_reg(dev->i2s_base, IMR(i));
 			i2s_write_reg(dev->i2s_base, IMR(i), irq & ~0x30);
 		}
 		i2s_write_reg(dev->i2s_base, ITER, 1);
 	} else {
-		for (i = 0; i < 4; i++) {
+		for (i = 0; i < (config->chan_nr / 2); i++) {
 			irq = i2s_read_reg(dev->i2s_base, IMR(i));
 			i2s_write_reg(dev->i2s_base, IMR(i), irq & ~0x03);
 		}
-- 
1.9.1