Replace SNDRV_DMA_TYPE_DEV by SNDRV_DMA_TYPE_NONCOHERENT for pcm
buffer allocation. We measured about 18x performance improvement
when accessing the snd_pcm_mmap() buffer from userspace.
Eg: aarch64 with internal speaker
==
SNDRV_DMA_TYPE_DEV
frames_per_second=66.4557M/s
max_time_per_4096_frames=106.094u
time_per_4096_frames=61.6351us
SNDRV_DMA_TYPE_NONCOHERENT
frames_per_second=1028.58M/s
max_time_per_4096_frames=20.312u
time_per_4096_frames=3.98221us
Signed-off-by: Judy Hsiao <judyhsiao@xxxxxxxxxxxx>
---
sound/soc/qcom/lpass-platform.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/soc/qcom/lpass-platform.c b/sound/soc/qcom/lpass-platform.c
index b41ab7a321ae..ef5cb40b2d9b 100644
--- a/sound/soc/qcom/lpass-platform.c
+++ b/sound/soc/qcom/lpass-platform.c
@@ -1181,7 +1181,7 @@ static int lpass_platform_pcm_new(struct snd_soc_component *component,
if (is_cdc_dma_port(dai_id))
return lpass_platform_prealloc_cdc_dma_buffer(component, pcm, dai_id);
- return snd_pcm_set_fixed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
+ return snd_pcm_set_fixed_buffer_all(pcm, SNDRV_DMA_TYPE_NONCOHERENT,
component->dev, size);
}
--
2.39.0.rc0.267.gcb52ba06e7-goog
