linux/sound/soc
Lars-Peter Clausen 3528f27a5d ASoC: dmaengine-pcm: Add support for querying stream position from DMA driver
Currently the sound dmaengine pcm helper functions implement the pcm_pointer
callback by trying to count the number of elapsed periods. This is done by
advancing the stream position in the dmaengine callback by one period.
Unfortunately there is no guarantee that the callback will be called for each
elapsed period. It may be possible that under high system load it is only called
once for multiple elapsed periods. This patch addresses the issue by
implementing support for querying the current stream position directly from the
dmaengine driver. Since not all dmaengine drivers support reporting the stream
position yet the old period counting implementation is kept for now.

Furthermore the new mechanism allows to report the stream position with a
sub-period granularity, given that the dmaengine driver supports this.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2012-06-20 15:39:05 +01:00
..
atmel
au1x
blackfin ASoC: add i2s dai driver for bf6xx soc 2012-06-20 11:26:54 +01:00
codecs ASoC: wm5100: Remove stubs of ASoC-level register map code 2012-06-19 12:43:26 +01:00
davinci
ep93xx ASoC: dmaengine-pcm: Rename and deprecate snd_dmaengine_pcm_pointer 2012-06-20 15:38:32 +01:00
fsl ASoC: dmaengine-pcm: Rename and deprecate snd_dmaengine_pcm_pointer 2012-06-20 15:38:32 +01:00
generic
jz4740
kirkwood
mid-x86
mxs ASoC: dmaengine-pcm: Rename and deprecate snd_dmaengine_pcm_pointer 2012-06-20 15:38:32 +01:00
nuc900
omap
pxa
s6000
samsung
sh
tegra
txx9
ux500 ASoC: dmaengine-pcm: Rename and deprecate snd_dmaengine_pcm_pointer 2012-06-20 15:38:32 +01:00
Kconfig
Makefile
soc-cache.c
soc-core.c
soc-dapm.c
soc-dmaengine-pcm.c ASoC: dmaengine-pcm: Add support for querying stream position from DMA driver 2012-06-20 15:39:05 +01:00
soc-io.c
soc-jack.c
soc-pcm.c
soc-utils.c