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

[Takashi Iwai]

On Tue, 13 Dec 2016 00:06:56 +0100,
Takashi Sakamoto wrote:
> 
> 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.

I leave these, as they are basically harmless.
I'll take once when I get acks from Intel people.


thanks,

Takashi


> [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
>