linux-kernel-test/include/sound
David Dillow 5daeba34d2 ALSA: pcm_lib: avoid timing jitter in snd_pcm_read/write()
When using poll() to wait for the next period -- or avail_min samples --
one gets a consistent delay for each system call that is usually just a
little short of the selected period time. However, When using
snd_pcm_read/write(), one gets a jittery delay that alternates between
less than a millisecond and approximately two period times. This is
caused by snd_pcm_lib_{read,write}1() transferring any available samples
to the user's buffer and adjusting the application pointer prior to
sleeping to the end of the current period. When the next period
interrupt occurs, there is then less than avail_min samples remaining to
be transferred in the period, so we end up sleeping until a second
period occurs.

This is solved by using runtime->twake as the number of samples needed
for a wakeup in addition to selecting the proper wait queue to wake in
snd_pcm_update_state(). This requires twake to be non-zero when used
by snd_pcm_lib_{read,write}1() even if avail_min is zero.

Signed-off-by: Dave Dillow <dave@thedillows.org>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
2010-06-28 09:42:09 +02:00
..
ac97_codec.h comment typo fix: sybsystem -> subsystem 2009-12-04 15:39:49 +01:00
aci.h ALSA: opti-miro: expose ACI mixer to outside drivers 2009-11-23 09:41:55 +01:00
ad1816a.h ALSA: ad1816a: enable hardware timer 2009-01-21 15:12:40 +01:00
ad1843.h ALSA: ALSA driver for SGI O2 audio board 2008-07-14 09:01:02 +02:00
ak4xxx-adda.h ALSA: ak4620 support, codec regs listed in proc 2009-09-21 15:44:51 +02:00
ak4113.h ALSA: i2c: cleanup: change parameter to pointer 2010-04-04 12:21:39 +02:00
ak4114.h ALSA: ak4114 - fix errors in output selector bits 2009-09-21 15:44:39 +02:00
ak4117.h
ak4531_codec.h
asequencer.h
asound_fm.h
asound.h ALSA: include/sound/asound.h whitespace fixups 2010-05-11 22:41:50 +02:00
asoundef.h ALSA: IEC958 definition for consumer status channel update 2008-08-01 13:13:13 +02:00
atmel-abdac.h ALSA: Add ALSA driver for Atmel Audio Bitstream DAC 2009-02-05 15:08:48 +01:00
atmel-ac97c.h ALSA: Add ALSA driver for Atmel AC97 controller 2009-02-05 15:08:51 +01:00
control.h control: use reference-counted pid 2009-11-06 14:32:06 +01:00
core.h ALSA: Add snd_pci_quirk_lookup_id() 2010-01-14 09:18:48 +01:00
cs46xx_dsp_scb_types.h
cs46xx_dsp_spos.h ALSA: cs46xx - Fix suspend/resume with new DSP 2009-12-22 09:00:14 +01:00
cs46xx_dsp_task_types.h
cs46xx.h
cs4231-regs.h ALSA: cs4236: update control names 2009-11-18 07:23:16 +01:00
cs8403.h
cs8427.h
emu10k1_synth.h
emu10k1.h emu101k1.h: fix duplicate include of <linux/types.h> 2009-03-26 18:14:24 +01:00
emu8000_reg.h
emu8000.h
emux_legacy.h
emux_synth.h
es1688.h ALSA: Merge es1688 and es968 drivers 2010-05-10 09:49:30 +02:00
gus.h
hda_hwdep.h
hdsp.h headers_check fix: sound/hdsp.h 2009-01-31 00:13:56 +05:30
hdspm.h
hwdep.h ALSA: hwdep - Fix coding style 2009-02-05 09:17:50 +01:00
i2c.h
info.h ALSA: info - Use standard types for info callbacks 2010-04-13 11:57:14 +02:00
initval.h
jack.h ALSA: Add support for key reporting via the jack interface 2010-03-17 18:10:46 +00:00
Kbuild ALSA: sscape - Remove sscap_ioctl.h from include/sound/Kbuild 2009-10-02 07:22:58 +02:00
l3.h ASoC: UDA134x codec driver 2008-11-17 11:45:39 +00:00
memalloc.h ALSA: Fix SG-buffer DMA with non-coherent architectures 2009-07-08 14:20:20 +02:00
minors.h ALSA: Fix limit of 8 PCM devices in SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE 2008-08-01 13:37:15 +02:00
mixer_oss.h
mpu401.h [ALSA] Add MPU401_INFO_NO_ACK bitflag 2008-04-29 19:01:56 +02:00
opl3.h
opl4.h
pcm_oss.h ALSA: pcm_lib - cleanup & merge hw_ptr update functions 2010-01-07 15:47:38 +01:00
pcm_params.h
pcm-indirect.h
pcm.h ALSA: pcm_lib: avoid timing jitter in snd_pcm_read/write() 2010-06-28 09:42:09 +02:00
pt2258.h
pxa2xx-lib.h [ARM] pxa: merge AC97 platform data structures 2009-04-15 10:54:06 +08:00
rawmidi.h sound: rawmidi: record a substream's owner process 2009-11-10 16:32:38 +01:00
s3c24xx_uda134x.h ASoC: Machine driver for for s3c24xx with uda134x 2008-11-17 11:45:53 +00:00
sb16_csp.h
sb.h ALSA: jazz16: Add support for Media Vision Jazz16 chipset 2009-12-21 12:09:22 +01:00
seq_device.h
seq_kernel.h ALSA: remove CONFIG_KMOD from sound 2008-07-10 09:32:58 +02:00
seq_midi_emul.h
seq_midi_event.h
seq_oss_legacy.h
seq_oss.h
seq_virmidi.h
sfnt_info.h ALSA: Use define for ioctl definitions 2009-03-11 09:55:03 +01:00
sh_dac_audio.h ALSA: sh: add SuperH DAC audio driver for ALSA V4 2009-11-04 09:17:40 +01:00
sh_fsi.h ASoC: Add SuperH FSI driver support for ALSA 2009-08-20 20:01:42 +01:00
snd_wavefront.h ALSA: wss_lib: rename cs4231.h into wss.h 2008-08-06 15:39:47 +02:00
soc-dai.h ALSA: ASoC: move dma_data from snd_soc_dai to snd_soc_pcm_stream 2010-04-05 19:14:11 +01:00
soc-dapm.h ASoC: Support leaving paths enabled over system suspend 2010-05-10 10:36:48 +01:00
soc-of-simple.h ALSA: ASoC: Make OpenFirmware helper include file conditional 2008-07-29 21:32:22 +02:00
soc.h ASoC: core: Fix for the volume limiting when invert is in use 2010-05-11 09:34:11 +01:00
soundfont.h
tea575x-tuner.h V4L/DVB (10771): tea575x-tuner: convert it to V4L2 API 2009-03-30 12:43:02 -03:00
tea6330t.h
timer.h
tlv320aic3x.h ASoC: tlv320aic3x: Add platform data and reset gpio handling 2010-05-06 14:58:02 +01:00
tlv320dac33-plat.h ASoC: tlv320dac33: Add option for keeping the BCLK running 2010-03-12 11:12:25 +00:00
tlv.h ALSA: Add new TLV types for dBwith min/max 2009-06-17 10:56:53 +02:00
tpa6130a2-plat.h Revert "ASoC: tpa6130a2: Support for limiting gain" 2010-05-07 16:42:23 +01:00
trident.h
uda134x.h ASoC: UDA134X: Add UDA1345 CODEC support 2010-04-26 15:28:18 +01:00
uda1380.h ASoC: UDA1380: refactor device registration 2009-06-15 21:54:48 +01:00
util_mem.h
version.h ALSA: Release v1.0.23 2010-04-16 13:12:36 +02:00
vx_core.h ALSA: Kill snd_assert() in other places 2008-08-13 11:46:40 +02:00
wavefront.h
wm2000.h ASoC: Add WM2000 driver 2010-02-12 10:31:06 +00:00
wm8903.h ASoC: Implement interrupt driven microphone detection for WM8903 2010-03-16 15:57:43 +00:00
wm8904.h ASoC: Support GPIO based microphone detection for WM8904 2010-03-16 16:03:30 +00:00
wm8955.h ASoC: Add initial WM8955 CODEC driver 2009-12-18 13:06:47 +00:00
wm8960.h ASoC: Add support for WM8960 capless mode 2010-03-03 17:08:43 +00:00
wm8993.h tree-wide: fix assorted typos all over the place 2009-12-04 15:39:55 +01:00
wm9081.h ASoC: WM9081 mono DAC with integrated 2.6W class AB/D amplifier driver 2009-05-22 15:11:22 +01:00
wm9090.h ASoC: Add WM9090 amplifier driver 2010-04-30 16:12:44 +01:00
wss.h ALSA: cs4236: detect chip in one pass 2009-11-05 18:10:25 +01:00
ymfpci.h sound: ymfpci: increase timer resolution to 96 kHz 2009-08-10 13:14:46 +02:00