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@chromium.org>
Link: https://lore.kernel.org/r/20221208084200.2136311-1-judyhsiao@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>
01270f905e