ALSA: doc: ReSTize Procfile document
A simple conversion from a text file. A new subidrectory, Documentation/sound/designs, was created to put this document. The other API design and implementation docuemnts will be put to that directory in later commits. Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai
Родитель
f6d23df5ca
Коммит
afb8fd3c72
|
|
@ -0,0 +1,7 @@
|
|||
Designs and Implementations
|
||||
===========================
|
||||
|
||||
.. toctree::
|
||||
:maxdepth: 2
|
||||
|
||||
procfile
|
||||
|
|
@ -1,20 +1,22 @@
|
|||
Proc Files of ALSA Drivers
|
||||
==========================
|
||||
Takashi Iwai <tiwai@suse.de>
|
||||
==========================
|
||||
Proc Files of ALSA Drivers
|
||||
==========================
|
||||
|
||||
Takashi Iwai <tiwai@suse.de>
|
||||
|
||||
General
|
||||
-------
|
||||
=======
|
||||
|
||||
ALSA has its own proc tree, /proc/asound. Many useful information are
|
||||
found in this tree. When you encounter a problem and need debugging,
|
||||
check the files listed in the following sections.
|
||||
|
||||
Each card has its subtree cardX, where X is from 0 to 7. The
|
||||
card-specific files are stored in the card* subdirectories.
|
||||
card-specific files are stored in the ``card*`` subdirectories.
|
||||
|
||||
|
||||
Global Information
|
||||
------------------
|
||||
==================
|
||||
|
||||
cards
|
||||
Shows the list of currently configured ALSA drivers,
|
||||
|
|
@ -31,15 +33,15 @@ devices
|
|||
|
||||
meminfo
|
||||
Shows the status of allocated pages via ALSA drivers.
|
||||
Appears only when CONFIG_SND_DEBUG=y.
|
||||
Appears only when ``CONFIG_SND_DEBUG=y``.
|
||||
|
||||
hwdep
|
||||
Lists the currently available hwdep devices in format of
|
||||
<card>-<device>: <name>
|
||||
``<card>-<device>: <name>``
|
||||
|
||||
pcm
|
||||
Lists the currently available PCM devices in format of
|
||||
<card>-<device>: <id>: <name> : <sub-streams>
|
||||
``<card>-<device>: <id>: <name> : <sub-streams>``
|
||||
|
||||
timer
|
||||
Lists the currently available timer devices
|
||||
|
|
@ -54,23 +56,23 @@ oss/sndstat
|
|||
|
||||
|
||||
Card Specific Files
|
||||
-------------------
|
||||
===================
|
||||
|
||||
The card-specific files are found in /proc/asound/card* directories.
|
||||
The card-specific files are found in ``/proc/asound/card*`` directories.
|
||||
Some drivers (e.g. cmipci) have their own proc entries for the
|
||||
register dump, etc (e.g. /proc/asound/card*/cmipci shows the register
|
||||
register dump, etc (e.g. ``/proc/asound/card*/cmipci`` shows the register
|
||||
dump). These files would be really helpful for debugging.
|
||||
|
||||
When PCM devices are available on this card, you can see directories
|
||||
like pcm0p or pcm1c. They hold the PCM information for each PCM
|
||||
stream. The number after 'pcm' is the PCM device number from 0, and
|
||||
the last 'p' or 'c' means playback or capture direction. The files in
|
||||
stream. The number after ``pcm`` is the PCM device number from 0, and
|
||||
the last ``p`` or ``c`` means playback or capture direction. The files in
|
||||
this subtree is described later.
|
||||
|
||||
The status of MIDI I/O is found in midi* files. It shows the device
|
||||
The status of MIDI I/O is found in ``midi*`` files. It shows the device
|
||||
name and the received/transmitted bytes through the MIDI device.
|
||||
|
||||
When the card is equipped with AC97 codecs, there are codec97#*
|
||||
When the card is equipped with AC97 codecs, there are ``codec97#*``
|
||||
subdirectories (described later).
|
||||
|
||||
When the OSS mixer emulation is enabled (and the module is loaded),
|
||||
|
|
@ -81,26 +83,27 @@ details.
|
|||
|
||||
|
||||
PCM Proc Files
|
||||
--------------
|
||||
==============
|
||||
|
||||
card*/pcm*/info
|
||||
``card*/pcm*/info``
|
||||
The general information of this PCM device: card #, device #,
|
||||
substreams, etc.
|
||||
|
||||
card*/pcm*/xrun_debug
|
||||
This file appears when CONFIG_SND_DEBUG=y and
|
||||
CONFIG_PCM_XRUN_DEBUG=y.
|
||||
``card*/pcm*/xrun_debug``
|
||||
This file appears when ``CONFIG_SND_DEBUG=y`` and
|
||||
``CONFIG_PCM_XRUN_DEBUG=y``.
|
||||
This shows the status of xrun (= buffer overrun/xrun) and
|
||||
invalid PCM position debug/check of ALSA PCM middle layer.
|
||||
It takes an integer value, can be changed by writing to this
|
||||
file, such as
|
||||
file, such as::
|
||||
|
||||
# echo 5 > /proc/asound/card0/pcm0p/xrun_debug
|
||||
|
||||
The value consists of the following bit flags:
|
||||
bit 0 = Enable XRUN/jiffies debug messages
|
||||
bit 1 = Show stack trace at XRUN / jiffies check
|
||||
bit 2 = Enable additional jiffies check
|
||||
|
||||
* bit 0 = Enable XRUN/jiffies debug messages
|
||||
* bit 1 = Show stack trace at XRUN / jiffies check
|
||||
* bit 2 = Enable additional jiffies check
|
||||
|
||||
When the bit 0 is set, the driver will show the messages to
|
||||
kernel log when an xrun is detected. The debug message is
|
||||
|
|
@ -117,72 +120,74 @@ card*/pcm*/xrun_debug
|
|||
buggy) hardware that doesn't give smooth pointer updates.
|
||||
This feature is enabled via the bit 2.
|
||||
|
||||
card*/pcm*/sub*/info
|
||||
``card*/pcm*/sub*/info``
|
||||
The general information of this PCM sub-stream.
|
||||
|
||||
card*/pcm*/sub*/status
|
||||
``card*/pcm*/sub*/status``
|
||||
The current status of this PCM sub-stream, elapsed time,
|
||||
H/W position, etc.
|
||||
|
||||
card*/pcm*/sub*/hw_params
|
||||
``card*/pcm*/sub*/hw_params``
|
||||
The hardware parameters set for this sub-stream.
|
||||
|
||||
card*/pcm*/sub*/sw_params
|
||||
``card*/pcm*/sub*/sw_params``
|
||||
The soft parameters set for this sub-stream.
|
||||
|
||||
card*/pcm*/sub*/prealloc
|
||||
``card*/pcm*/sub*/prealloc``
|
||||
The buffer pre-allocation information.
|
||||
|
||||
card*/pcm*/sub*/xrun_injection
|
||||
``card*/pcm*/sub*/xrun_injection``
|
||||
Triggers an XRUN to the running stream when any value is
|
||||
written to this proc file. Used for fault injection.
|
||||
This entry is write-only.
|
||||
|
||||
AC97 Codec Information
|
||||
----------------------
|
||||
======================
|
||||
|
||||
card*/codec97#*/ac97#?-?
|
||||
``card*/codec97#*/ac97#?-?``
|
||||
Shows the general information of this AC97 codec chip, such as
|
||||
name, capabilities, set up.
|
||||
|
||||
card*/codec97#0/ac97#?-?+regs
|
||||
``card*/codec97#0/ac97#?-?+regs``
|
||||
Shows the AC97 register dump. Useful for debugging.
|
||||
|
||||
When CONFIG_SND_DEBUG is enabled, you can write to this file for
|
||||
changing an AC97 register directly. Pass two hex numbers.
|
||||
For example,
|
||||
|
||||
::
|
||||
|
||||
# echo 02 9f1f > /proc/asound/card0/codec97#0/ac97#0-0+regs
|
||||
|
||||
|
||||
USB Audio Streams
|
||||
-----------------
|
||||
=================
|
||||
|
||||
card*/stream*
|
||||
``card*/stream*``
|
||||
Shows the assignment and the current status of each audio stream
|
||||
of the given card. This information is very useful for debugging.
|
||||
|
||||
|
||||
HD-Audio Codecs
|
||||
---------------
|
||||
===============
|
||||
|
||||
card*/codec#*
|
||||
``card*/codec#*``
|
||||
Shows the general codec information and the attribute of each
|
||||
widget node.
|
||||
|
||||
card*/eld#*
|
||||
``card*/eld#*``
|
||||
Available for HDMI or DisplayPort interfaces.
|
||||
Shows ELD(EDID Like Data) info retrieved from the attached HDMI sink,
|
||||
and describes its audio capabilities and configurations.
|
||||
|
||||
Some ELD fields may be modified by doing `echo name hex_value > eld#*`.
|
||||
Some ELD fields may be modified by doing ``echo name hex_value > eld#*``.
|
||||
Only do this if you are sure the HDMI sink provided value is wrong.
|
||||
And if that makes your HDMI audio work, please report to us so that we
|
||||
can fix it in future kernel releases.
|
||||
|
||||
|
||||
Sequencer Information
|
||||
---------------------
|
||||
=====================
|
||||
|
||||
seq/drivers
|
||||
Lists the currently available ALSA sequencer drivers.
|
||||
|
|
@ -203,7 +208,7 @@ seq/oss
|
|||
|
||||
|
||||
Help For Debugging?
|
||||
-------------------
|
||||
===================
|
||||
|
||||
When the problem is related with PCM, first try to turn on xrun_debug
|
||||
mode. This will give you the kernel messages when and where xrun
|
||||
|
|
@ -211,24 +216,23 @@ happened.
|
|||
|
||||
If it's really a bug, report it with the following information:
|
||||
|
||||
- the name of the driver/card, show in /proc/asound/cards
|
||||
- the register dump, if available (e.g. card*/cmipci)
|
||||
- the name of the driver/card, show in ``/proc/asound/cards``
|
||||
- the register dump, if available (e.g. ``card*/cmipci``)
|
||||
|
||||
when it's a PCM problem,
|
||||
|
||||
- set-up of PCM, shown in hw_parms, sw_params, and status in the PCM
|
||||
sub-stream directory
|
||||
- set-up of PCM, shown in hw_parms, sw_params, and status in the PCM
|
||||
sub-stream directory
|
||||
|
||||
when it's a mixer problem,
|
||||
|
||||
- AC97 proc files, codec97#*/* files
|
||||
- AC97 proc files, ``codec97#*/*`` files
|
||||
|
||||
for USB audio/midi,
|
||||
|
||||
- output of lsusb -v
|
||||
- stream* files in card directory
|
||||
- output of ``lsusb -v``
|
||||
- ``stream*`` files in card directory
|
||||
|
||||
|
||||
The ALSA bug-tracking system is found at:
|
||||
|
||||
https://bugtrack.alsa-project.org/alsa-bug/
|
||||
https://bugtrack.alsa-project.org/alsa-bug/
|
||||
|
|
@ -6,6 +6,7 @@ Linux Sound Subsystem Documentation
|
|||
:maxdepth: 2
|
||||
|
||||
kernel-api/index
|
||||
designs/index
|
||||
alsa-configuration
|
||||
hd-audio/index
|
||||
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче