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linux/sound/soc/omap
Jarkko Nikula c12abc012e ARM: OMAP: McBSP: Fix ASoC on OMAP1510 by fixing API of omap_mcbsp_start/stop
Simultaneous audio playback and capture on OMAP1510 can cause that second
stream is stalled if there is enough delay between startup of the audio
streams.

Current implementation of the omap_mcbsp_start is starting both transmitter
and receiver at the same time and it is called only for firstly started
audio stream from the OMAP McBSP based ASoC DAI driver.

Since DMA request lines on OMAP1510 are edge sensitive, the DMA request is
missed if there is no DMA transfer set up at that time when the first word
after McBSP startup is transmitted. The problem hasn't noted before since
later OMAPs are using level sensitive DMA request lines.

Fix the problem by changing API of omap_mcbsp_start and omap_mcbsp_stop by
allowing to start and stop individually McBSP transmitter and receiver
logics. Then call those functions individually for both audio playback
and capture streams. This ensures that DMA transfer is setup before
transmitter or receiver is started.

Thanks to Janusz Krzysztofik <jkrzyszt@tis.icnet.pl> for detailed problem
analysis and Peter Ujfalusi <peter.ujfalusi@nokia.com> for info about DMA
request line behavior differences between the OMAP generations.

Reported-and-tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-08-07 10:57:42 +01:00
..
Kconfig ASoC: Added OMAP3 EVM support in ASoC. 2009-05-14 12:47:26 +01:00
Makefile ASoC: Added OMAP3 EVM support in ASoC. 2009-05-14 12:47:26 +01:00
n810.c Merge branch 'for-2.6.30' into for-2.6.31 2009-04-20 12:45:40 +01:00
omap2evm.c ASoC: TWL4030: Add support Voice DAI 2009-04-20 12:44:24 +01:00
omap3beagle.c ASoC: Beagle: Add support for 4 channel 2009-04-24 17:38:25 +01:00
omap3evm.c ASoC: Added OMAP3 EVM support in ASoC. 2009-05-14 12:47:26 +01:00
omap3pandora.c ASoC: TWL4030: Add support Voice DAI 2009-04-20 12:44:24 +01:00
omap-mcbsp.c ARM: OMAP: McBSP: Fix ASoC on OMAP1510 by fixing API of omap_mcbsp_start/stop 2009-08-07 10:57:42 +01:00
omap-mcbsp.h ASoC: OMAP: Update contact addresses 2009-04-17 15:55:09 +01:00
omap-pcm.c ASoC: OMAP: fix OMAP1510 broken PCM pointer callback 2009-06-30 10:39:12 +01:00
omap-pcm.h ASoC: OMAP: Update contact addresses 2009-04-17 15:55:09 +01:00
osk5912.c ASoC: OMAP: Fix FS polarity in OSK5912 machine driver 2009-04-16 13:37:26 +01:00
overo.c ASoC: TWL4030: Add support Voice DAI 2009-04-20 12:44:24 +01:00
sdp3430.c ASoC: SDP4030: Use the twl4030_setup_data for headset pop-removal 2009-05-22 10:23:22 +01:00