linux/sound
Mark Brown 11d4e47486
ASoC: mchp-pdmc: fix poc noises when starting
Merge series from Claudiu Beznea <claudiu.beznea@microchip.com>:

To start capture on Microchip PDMC the enable bits for each supported
microphone need to be set. After this bit is set the PDMC starts to
receive data from microphones and it considers this data as valid data.
Thus if microphones are not ready the PDMC captures anyway data from its
lines. This data is interpreted by the human ear as poc noises.

To avoid this the following software workaround need to be applied when
starting capture:
1/ enable PDMC channel
2/ wait 150ms
3/ execute 16 dummy reads from RHR
4/ clear interrupts
5/ enable interrupts
6/ enable DMA channel

For this workaround to work step 6 need to be executed at the end.
For step 6 was added patch 1/3 from this series. With this, component
DAI driver sets its struct snd_soc_component_driver::start_dma_last = 1
and proper action is taken based on this flag when starting DAI trigger
vs DMA.
2023-02-28 17:59:15 +00:00
..
ac97 ALSA: ac97: Replace sprintf() with sysfs_emit() 2022-08-02 16:03:41 +02:00
aoa ALSA: aoa: tas: Convert to i2c's .probe_new() 2022-11-19 09:43:27 +01:00
arm ALSA: arm: pxa: pxa2xx-ac97-lib: fix return value check of platform_get_irq() 2022-10-29 10:45:27 +02:00
atmel
core Merge branch 'for-next' into for-linus 2022-12-22 09:11:48 +01:00
drivers ALSA: mts64: fix possible null-ptr-defer in snd_mts64_interrupt 2022-12-06 11:12:12 +01:00
firewire Merge branch 'for-next' into for-linus 2022-12-22 09:11:48 +01:00
hda ALSA: hda: Error out if invalid stream is being setup 2022-12-09 09:54:53 +01:00
i2c treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
isa ALSA: sb: Use DIV_ROUND_UP() instead of open-coding it 2022-09-29 08:11:55 +02:00
mips
oss sound: oss: dmasound: remove software_input_volume declaration 2022-09-09 09:11:06 +02:00
parisc
pci ALSA: azt3328: Remove the unused function snd_azf3328_codec_outl() 2022-12-22 09:12:26 +01:00
pcmcia ALSA: pdaudiocf: Drop superfluous GFP setup 2022-08-24 08:00:26 +02:00
ppc ALSA: ppc: keywest: Convert to i2c's .probe_new() 2022-11-19 09:43:50 +01:00
sh
soc ASoC: mchp-pdmc: fix poc noises when starting 2023-02-28 17:59:15 +00:00
sparc
spi sound:spi: remove reference to AVR32 in Atmel AT73C213 DAC driver 2022-08-03 11:11:26 +02:00
synth treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
usb ALSA: usb-audio: Add new quirk FIXED_RATE for JBL Quantum810 Wireless 2022-12-22 09:13:54 +01:00
virtio
x86
xen
ac97_bus.c
Kconfig
last.c
Makefile
sound_core.c driver core: make struct class.devnode() take a const * 2022-11-24 17:12:27 +01:00