[PATCH] ASoC: AMD: Do not generate interrups for every captured sample

From: Daniel Kurtz
Date: Mon Jul 02 2018 - 17:19:54 EST


On capture, audio data is first copied from I2S to ACP memory, and then
from ACP to SYSRAM. The I2S_TO_ACP_DMA interrupt fires on every sample
transferred from I2S to ACP memory. That is it fires ~48000 times per
second when capturing @ 48 kHz. Since we don't do anything on this
interrupt anyway, disable it to save quite a few unnecessary interrupts.
The real "work" (calling snd_pcm_period_elapsed()) is done when transfer
from ACP to SYSRAM is complete.

Signed-off-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
sound/soc/amd/acp-pcm-dma.c | 15 ---------------
1 file changed, 15 deletions(-)

diff --git a/sound/soc/amd/acp-pcm-dma.c b/sound/soc/amd/acp-pcm-dma.c
index df53412967e1..cd4d2520ac14 100644
--- a/sound/soc/amd/acp-pcm-dma.c
+++ b/sound/soc/amd/acp-pcm-dma.c
@@ -412,10 +412,8 @@ static void acp_dma_start(void __iomem *acp_mmio, u16 ch_num)
switch (ch_num) {
case ACP_TO_I2S_DMA_CH_NUM:
case ACP_TO_SYSRAM_CH_NUM:
- case I2S_TO_ACP_DMA_CH_NUM:
case ACP_TO_I2S_DMA_BT_INSTANCE_CH_NUM:
case ACP_TO_SYSRAM_BT_INSTANCE_CH_NUM:
- case I2S_TO_ACP_DMA_BT_INSTANCE_CH_NUM:
dma_ctrl |= ACP_DMA_CNTL_0__DMAChIOCEn_MASK;
break;
default:
@@ -704,12 +702,6 @@ static irqreturn_t dma_irq_handler(int irq, void *arg)
acp_mmio, mmACP_EXTERNAL_INTR_STAT);
}

- if ((intr_flag & BIT(I2S_TO_ACP_DMA_CH_NUM)) != 0) {
- valid_irq = true;
- acp_reg_write((intr_flag & BIT(I2S_TO_ACP_DMA_CH_NUM)) << 16,
- acp_mmio, mmACP_EXTERNAL_INTR_STAT);
- }
-
if ((intr_flag & BIT(ACP_TO_SYSRAM_BT_INSTANCE_CH_NUM)) != 0) {
valid_irq = true;
snd_pcm_period_elapsed(irq_data->capture_i2sbt_stream);
@@ -718,13 +710,6 @@ static irqreturn_t dma_irq_handler(int irq, void *arg)
acp_mmio, mmACP_EXTERNAL_INTR_STAT);
}

- if ((intr_flag & BIT(I2S_TO_ACP_DMA_BT_INSTANCE_CH_NUM)) != 0) {
- valid_irq = true;
- acp_reg_write((intr_flag &
- BIT(I2S_TO_ACP_DMA_BT_INSTANCE_CH_NUM)) << 16,
- acp_mmio, mmACP_EXTERNAL_INTR_STAT);
- }
-
if (valid_irq)
return IRQ_HANDLED;
else
--
2.18.0.rc2