The Advanced Linux Sound Architecture (ALSA) - library
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Takashi Sakamoto d008e1ac20 pcm: fix wrong document references to PCM APIs which perform direct memory access with frame copying
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@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-12-12 22:36:29 +01:00
alsalisp autotools: update style 2014-02-26 08:16:22 +01:00
aserver coverity fixes 2016-01-12 16:26:58 +01:00
doc doxygen: Suppress timestamp 2016-06-23 16:29:07 +02:00
include topology: Revise document and comments for ABI v5 2016-11-22 07:50:30 +01:00
m4 Add the attributes.m4 macro file from xine/lscube. 2008-11-21 13:04:19 +01:00
modules mixer: Don't install smixer modules unless python is enabled 2016-11-14 11:46:05 +01:00
src pcm: fix wrong document references to PCM APIs which perform direct memory access with frame copying 2016-12-12 22:36:29 +01:00
test test: use actual information for TLV operation 2016-09-30 17:12:38 +02:00
utils autotools: update style 2014-02-26 08:16:22 +01:00
.gitignore Add pcm-multi-thread to .gitignore 2016-07-07 16:30:54 +02:00
acinclude.m4 fixed for the recent autoconf. 2004-01-26 15:52:17 +00:00
ChangeLog * update to libtool 1.3.3 1999-07-22 12:18:42 +00:00
configure.ac conf/ucm: skylake: add skylake-rt286 conf files 2016-10-10 11:59:44 +02:00
COPYING Updated GNU GPL license (address). 2001-12-30 09:22:54 +00:00
gitcompile Introduce --with-pkgconfdir, add 64-bit defaults to gitcompile 2012-01-20 16:14:44 +01:00
INSTALL pcm: Add thread-safety to PCM API 2016-07-11 15:25:30 +02:00
Makefile.am autotools: update style 2014-02-26 08:16:22 +01:00
MEMORY-LEAK Initial version 2003-02-04 14:56:07 +00:00
NOTES Change assert condition in error message handler 2007-10-24 12:53:08 +02:00
TODO Added snd_config_load_override(). 2002-01-09 21:28:15 +00:00