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643518403c
When being powered on, either initially on probe or when resuming from suspend, the wm8971 configures the device for quick output capacitor charging. Since the charging can take a rather long time (up to multiple seconds) it is done asynchronously without blocking. A delayed work item is run once the charging is finished and the device is switched to the target bias level. This all done asynchronously to the regular DAPM sequence accessing the same data structures and registers without any looking, which can lead to race conditions. Furthermore this potentially delays the start of stream on the CODEC while the rest of the system is already up and running, meaning the first bytes of audio are lost. It also does no comply with the assumption of the DAPM core that if set_bias_level() returned successfully the device will be at the requested bias level. This patch slightly refactors things and makes sure that the caps charging is properly integrated into the DAPM sequence. When transitioning from SND_SOC_BIAS_OFF to SND_SOC_BIAS_STANDBY the part will be put into fast charging mode and a work item will be scheduled that puts it back into standby charging once the charging period has elapsed. If a playback or capture stream is started while charging is in progress the driver will now wait in SND_SOC_BIAS_PREPARE until the charging is done. This makes sure that charging is done asynchronously in the background when the chip is idle, but at the same time makes sure that playback/capture is not started before the charging is done. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@kernel.org> |
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| .. | ||
| aoa | ||
| arm | ||
| atmel | ||
| core | ||
| drivers | ||
| firewire | ||
| i2c | ||
| isa | ||
| mips | ||
| oss | ||
| parisc | ||
| pci | ||
| pcmcia | ||
| ppc | ||
| sh | ||
| soc | ||
| sparc | ||
| spi | ||
| synth | ||
| usb | ||
| ac97_bus.c | ||
| Kconfig | ||
| last.c | ||
| Makefile | ||
| sound_core.c | ||
| sound_firmware.c | ||