[alsa-devel] [PATCH v3 1/2] ASoC: SOF: add flag for position update ipc

[Pierre-Louis Bossart]

On 7/17/19 10:11 PM, Keyon Jie wrote:
> From: Marcin Rajwa <marcin.rajwa at linux.intel.com>
> 
> In some cases, FW might need to use the host_period_bytes field to
> synchronize the DMA copying (with host side) but the driver does not

it's your right to edit my suggested wording, but the notion of 
'synchronization' is far from clear. it's my understanding that the 
host_period_bytes defines the DMA transfer size requested by the 
firmware, which isn't a value that matters to the host except for rewind 
usages.

> need any position information returned over the IPC channel by the
> firmware. The current IPC definition prevents this capability, so add
> new field.
> 
> Signed-off-by: Marcin Rajwa <marcin.rajwa at linux.intel.com>
> Signed-off-by: Keyon Jie <yang.jie at linux.intel.com>
> Reviewed-by: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>
> ---
>   include/sound/sof/stream.h | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/include/sound/sof/stream.h b/include/sound/sof/stream.h
> index 643f175cb479..06af4ecb2584 100644
> --- a/include/sound/sof/stream.h
> +++ b/include/sound/sof/stream.h
> @@ -83,10 +83,10 @@ struct sof_ipc_stream_params {
>   	uint16_t sample_valid_bytes;
>   	uint16_t sample_container_bytes;
>   
> -	/* for notifying host period has completed - 0 means no period IRQ */
>   	uint32_t host_period_bytes;
> +	uint32_t no_position_ipc; /* 1 means no IPC for position upadte */

typo: update

>   
> -	uint32_t reserved[2];
> +	uint16_t reserved[3];
>   	uint16_t chmap[SOF_IPC_MAX_CHANNELS];	/**< channel map - SOF_CHMAP_ */
>   } __packed;
>   
>