[alsa-devel] [PATCH 1/6] Documentation: soundwire: Add documentation for Multi link

[Vinod]

On 05-06-18, 16:31, Shreyas NC wrote:
> From: Sanyog Kale <sanyog.r.kale at intel.com>
> 
> Add example and documentation to describe Multi Link streams
> 
> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
> Signed-off-by: Sanyog Kale <sanyog.r.kale at intel.com>
> Signed-off-by: Vinod Koul <vkoul at kernel.org>
> Signed-off-by: Shreyas NC <shreyas.nc at intel.com>
> ---
>  Documentation/driver-api/soundwire/stream.rst | 30 ++++++++++++++++++++++++++-
>  1 file changed, 29 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/driver-api/soundwire/stream.rst b/Documentation/driver-api/soundwire/stream.rst
> index 29121aa..af9529b 100644
> --- a/Documentation/driver-api/soundwire/stream.rst
> +++ b/Documentation/driver-api/soundwire/stream.rst
> @@ -76,7 +76,35 @@ Slaves are using single port. ::
>  	                                                   +---------------+
>  
>  
> -Example 4: Stereo Stream with L and R channel is rendered by two different
> +Example 4: Stereo Stream with L and R channel is rendered by 2 Masters, each

We already have an example 4, shouldn't this be 5th one, can you check?
I would prefer adding new example at the end and not in middle..

> +rendering one channel, and is received by two different Slaves, each
> +receiving one channel. Both Masters and both Slaves are using single port. ::
> +
> +	+---------------+                    Clock Signal  +---------------+
> +	|    Master     +----------------------------------+     Slave     |
> +	|   Interface   |                                  |   Interface   |
> +	|       1       |                                  |       1       |
> +	|               |                     Data Signal  |               |
> +	|       L       +----------------------------------+       L       |
> +	|     (Data)    |     Data Direction               |     (Data)    |
> +	+---------------+  +----------------------->       +---------------+
> +
> +	+---------------+                    Clock Signal  +---------------+
> +	|    Master     +----------------------------------+     Slave     |
> +	|   Interface   |                                  |   Interface   |
> +	|       2       |                                  |       2       |
> +	|               |                     Data Signal  |               |
> +	|       R       +----------------------------------+       R       |
> +	|     (Data)    |     Data Direction               |     (Data)    |
> +	+---------------+  +----------------------->       +---------------+
> +
> +Note: In multi-link cases like above, to lock, one would acquire a global
> +lock and then go on locking bus instances. But, in this case the caller
> +framework(ASoC DPCM) guarantees that stream operations on a card are
> +always serialized. So, there is no race condition and hence no need for
> +global lock.
> +
> +Example 5: Stereo Stream with L and R channel is rendered by two different
>  Ports of the Master and is received by only single Port of the Slave
>  interface. ::
>  
> -- 
> 2.7.4

-- 
~Vinod