[alsa-devel] [PATCH v3 0/2] ALSA: Add PCM USER_PVERSION ioctl

[Takashi Sakamoto]

On Jun 27 2017 20:58, Takashi Iwai wrote:
> On Tue, 27 Jun 2017 13:43:43 +0200,
> Takashi Sakamoto wrote:
>>
>> Hi,
>>
>> On Jun 27 2017 19:29, Takashi Iwai wrote:
>>> Hi,
>>>
>>> this is a revised patchset that is applied on top of the current
>>> for-next branch, in order to optimize the appl_ptr sync on x86-64,
>>> adapting the alsa-lib side change by Sakamoto-san's patchset.
>>>
>>> Basically it adds a new ioctl for receiving the supported PCM protocol
>>> version from user-space side, and change the mmap code to allow only
>>> disabling the PCM status record depending on the supported protocol
>>> version.  The former patch is identical with the previous version,
>>> only the latter one differs.
>>>
>>> The corresponding alsa-lib patch will follow.
>>>
>>>
>>> thanks,
>>>
>>> Takashi
>>>
>>> ===
>>>
>>> Takashi Iwai (2):
>>>     ALSA: pcm: Add an ioctl to specify the supported protocol version
>>>     ALSA: pcm: Disable only control mmap for explicit appl_ptr sync
>>>
>>>    include/sound/pcm.h         |  1 +
>>>    include/uapi/sound/asound.h |  3 ++-
>>>    sound/core/pcm_compat.c     |  1 +
>>>    sound/core/pcm_native.c     | 29 ++++++++++++++++++++++++-----
>>>    4 files changed, 28 insertions(+), 6 deletions(-)
>>
>> Reviewed-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
>>
>> I note that the idea of USER_PVERSION ioctl is itself worth for the
>> other interfaces/protocols such as control. In the
>> interfaces/protocols, many structures have reserved members. As
>> Iwai-san described in the first patch, when changing them to utilize
>> these reserved members, this idea is a solution to balance
>> compatibility and extensibility.
> 
> OK, let's go with this.  I'll merge this and also the alsa-lib
> patchsets.

Good work, Takashi ;)

I have rest of my work for alsa-lib to optimize SYNC_PTR ioctl. Within a 
few days, I'll post it.


Thanks

Takashi Sakamoto