diff options
| author | Misael Lopez Cruz <misael.lopez@ti.com> | 2014-11-12 09:38:05 -0500 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2014-11-12 09:55:00 -0500 |
| commit | a7a3324a602cd7ebabfb7f5990006ec4f3d6449f (patch) | |
| tree | f77c68c09dec608db66c5e16b9010bd56359d4f4 /Documentation | |
| parent | 18a4f55756ac945bd89d1fe63dafe36462ecba86 (diff) | |
ASoC: davinci-mcasp: Add overrun/underrun event handling
An underrun (playback) event occurs when the serializer transfer
data from the XRBUF buffer to the XRSR shift register, but the
XRBUF hasn't been filled. Similarly, the overrun (capture) event
occurs when data from the XRSR shift register is transferred to
the XRBUF but it hasn't been read yet.
These events are handled as XRUN events that cause the pcm to stop.
The stream has to be explicitly restarted by the userspace which
ensures that after stopping/starting McASP the data transfer is
aligned with DMA. The other possibility was to internally stop and
start McASP without DMA even knowing about it.
Signed-off-by: Misael Lopez Cruz <misael.lopez@ti.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/sound/davinci-mcasp-audio.txt | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/sound/davinci-mcasp-audio.txt b/Documentation/devicetree/bindings/sound/davinci-mcasp-audio.txt index 60ca07996458..46bc9829c71a 100644 --- a/Documentation/devicetree/bindings/sound/davinci-mcasp-audio.txt +++ b/Documentation/devicetree/bindings/sound/davinci-mcasp-audio.txt | |||
| @@ -32,7 +32,7 @@ Optional properties: | |||
| 32 | - rx-num-evt : FIFO levels. | 32 | - rx-num-evt : FIFO levels. |
| 33 | - sram-size-playback : size of sram to be allocated during playback | 33 | - sram-size-playback : size of sram to be allocated during playback |
| 34 | - sram-size-capture : size of sram to be allocated during capture | 34 | - sram-size-capture : size of sram to be allocated during capture |
| 35 | - interrupts : Interrupt numbers for McASP, currently not used by the driver | 35 | - interrupts : Interrupt numbers for McASP |
| 36 | - interrupt-names : Known interrupt names are "tx" and "rx" | 36 | - interrupt-names : Known interrupt names are "tx" and "rx" |
| 37 | - pinctrl-0: Should specify pin control group used for this controller. | 37 | - pinctrl-0: Should specify pin control group used for this controller. |
| 38 | - pinctrl-names: Should contain only one value - "default", for more details | 38 | - pinctrl-names: Should contain only one value - "default", for more details |