[alsa-devel] [PATCH] pcm: fix wrong document references to PCM APIs which perform direct memory access with frame copying

[Takashi Sakamoto]

Hi,

On Dec 13 2016 06:36, Takashi Iwai wrote:
> On Sun, 11 Dec 2016 12:31:38 +0100,
> Takashi Sakamoto wrote:
>>
>> In a design of ALSA PCM interface, for PCM frame transmission to/from
>> kernel space, applications can select from two options; direct memory access
>> or ioctl(2). Available options are decided depending on device capacity and
>> machine architecture. Applications can get available options by the first
>> entry of 'struct snd_pcm_hw_params.masks'.
>>
>> When the mask includes 'SNDRV_PCM_ACCESS_MMAP_xxx', applications can use
>> direct memory access. For this use case, userspace library has two types
>> of PCM API. One is to expose a pointer over the memory to start
>> reading/writing PCM frames. Another is to copy PCM frames between the
>> memory and a given buffer.
>>
>> Current documentation includes wrong references to these APIs to describe
>> their advantages/disadvantages. This confuses application developers
>> because the references indicate PCM APIs to execute ioctl(2) operation to
>> read/write PCM frames.
>>
>> This commit fixes the bug.
>>
>> Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
>
> Applied, thanks.

Thanks.

Additionally, I'm pleased if you apply below patches to fix some 
compiler warnings which topology features recently got. I guess Intel 
developers are under their holidays.

[alsa-devel] [PATCH][alsa-lib] topology: fix sign-compare warning 
introduced to set_link_hw_config() and tplg_add_link_object()
http://mailman.alsa-project.org/pipermail/alsa-devel/2016-November/115245.html

[alsa-devel] [PATCH][alsa-lib] topology: fix unused-variable warnings 
introduced to build_link()
http://mailman.alsa-project.org/pipermail/alsa-devel/2016-November/115246.html

[alsa-devel] [PATCH][alsa-lib] topology: fix unused-const-variable warning
http://mailman.alsa-project.org/pipermail/alsa-devel/2016-November/115247.html


Regards

Takashi Sakamoto