[alsa-devel] [Xen-devel][PATCH v3 0/5] sndif: add explicit back and front synchronization

[Oleksandr Andrushchenko]

On 03/21/2018 09:20 AM, Takashi Iwai wrote:
> On Wed, 21 Mar 2018 08:15:36 +0100,
> Oleksandr Andrushchenko wrote:
>> On 03/20/2018 10:22 PM, Takashi Iwai wrote:
>>> On Mon, 19 Mar 2018 08:22:19 +0100,
>>> Oleksandr Andrushchenko wrote:
>>>> From: Oleksandr Andrushchenko <oleksandr_andrushchenko at epam.com>
>>>>
>>>> Hello, all!
>>>>
>>>> In order to provide explicit synchronization between backend and
>>>> frontend the following changes are introduced in the protocol:
>>>>    - bump protocol version to 2
>>>>    - add new ring buffer for sending asynchronous events from
>>>>      backend to frontend to report number of bytes played by the
>>>>      frontend (XENSND_EVT_CUR_POS)
>>>>    - introduce trigger events for playback control: start/stop/pause/resume
>>>>    - add "req-" prefix to event-channel and ring-ref to unify naming
>>>>      of the Xen event channels for requests and events
>>>>    - add XENSND_OP_HW_PARAM_QUERY request to read/update
>>>>      stream configuration space: request passes desired intervals/formats for
>>>>      the stream parameters and the response returns allowed intervals and
>>>>      formats mask that can be used.
>>>>
>>>> Changes since v2:
>>>> 1. Konrad's r-b tag for version patch
>>>> 2. MAJOR: changed req/resp/evt packet sizes from 32 to 64 octets
>>>> 3. Reworked XENSND_OP_HW_PARAM_QUERY so it now sends all
>>>>      parameters at once, allowing to check all the configuration
>>>>      space.
>>>> 4. Minor documentation cleanup (added missed "reserved" fields)
>>>>
>>>> Changes since v1:
>>>>
>>>> 1. Changed protocol version definition from string to integer,
>>>> so it can easily be used in comparisons.
>>>> Konrad, I have removed your r-b tag for the reason of this change.
>>>>
>>>> 2. In order to provide explicit stream parameter negotiation between
>>>> backend and frontend the following changes are introduced in the protocol:
>>>> add XENSND_OP_HW_PARAM_QUERY request to read/update
>>>> configuration space for the parameter given: request passes
>>>> desired parameter interval (mask) and the response to this request
>>>> returns min/max interval (mask) for the parameter to be used.
>>>>
>>>> Parameters supported by this request/response:
>>>>    - format mask
>>>>    - sample rate interval
>>>>    - number of channels interval
>>>>    - buffer size, interval, frames
>>>>    - period size, interval, frames
>>> I can't judge exactly about the protocol without the actual FE/BE
>>> implementations, but the change looks good to me, especially if you've
>>> already tested something.
>> Thank you, I have tested the changes and need them to start upstreaming
>> the frontend driver used to test the protocol.
>> Do you mind if I put your Acked-by (or you prefer Reviewed-by?) tag to
>> these patches:
>>
>> [PATCH v3 4/5] sndif: Add explicit back and front synchronization
>> [PATCH v3 5/5] sndif: Add explicit back and front parameter negotiation
> Sure, feel free to take my ack:
>    Reviewed-by: Takashi Iwai <tiwai at suse.de>
Thank you
>
> Takashi
>
>> Please note, that the changes first to be merged into Xen and then
>> I'll prepare
>> the same, but for the kernel
>>> If other people have no concern, let's go ahead with FE/BE stuff.
>> Konrad, are you ok with the changes?
>>> thanks,
>>>
>>> Takashi
>> Thank you,
>> Oleksandr
>>