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author | Takashi Iwai <tiwai@suse.de> | 2016-11-09 09:54:47 -0500 |
---|---|---|
committer | Takashi Iwai <tiwai@suse.de> | 2016-11-10 12:09:23 -0500 |
commit | 48e92b488d3c419e11bbf03c56ceb43399ac1901 (patch) | |
tree | 4ade68681f3976ca44656e4138610f45dc0ff91d /Documentation/sound | |
parent | afb8fd3c72a9f00018f7335590c173ce4cc2a43d (diff) |
ALSA: doc: ReSTize powersave document
A simple conversion from a text file.
Put into designs subdirectory, although it's mostly relevant with
HD-audio.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'Documentation/sound')
-rw-r--r-- | Documentation/sound/designs/index.rst | 1 | ||||
-rw-r--r-- | Documentation/sound/designs/powersave.rst (renamed from Documentation/sound/alsa/powersave.txt) | 16 |
2 files changed, 10 insertions, 7 deletions
diff --git a/Documentation/sound/designs/index.rst b/Documentation/sound/designs/index.rst index 82d19fe3c380..362e1c23d51f 100644 --- a/Documentation/sound/designs/index.rst +++ b/Documentation/sound/designs/index.rst | |||
@@ -5,3 +5,4 @@ Designs and Implementations | |||
5 | :maxdepth: 2 | 5 | :maxdepth: 2 |
6 | 6 | ||
7 | procfile | 7 | procfile |
8 | powersave | ||
diff --git a/Documentation/sound/alsa/powersave.txt b/Documentation/sound/designs/powersave.rst index 9657e8099228..138157452eb9 100644 --- a/Documentation/sound/alsa/powersave.txt +++ b/Documentation/sound/designs/powersave.rst | |||
@@ -1,9 +1,10 @@ | |||
1 | ========================== | ||
1 | Notes on Power-Saving Mode | 2 | Notes on Power-Saving Mode |
2 | ========================== | 3 | ========================== |
3 | 4 | ||
4 | AC97 and HD-audio drivers have the automatic power-saving mode. | 5 | AC97 and HD-audio drivers have the automatic power-saving mode. |
5 | This feature is enabled via Kconfig CONFIG_SND_AC97_POWER_SAVE | 6 | This feature is enabled via Kconfig ``CONFIG_SND_AC97_POWER_SAVE`` |
6 | and CONFIG_SND_HDA_POWER_SAVE options, respectively. | 7 | and ``CONFIG_SND_HDA_POWER_SAVE`` options, respectively. |
7 | 8 | ||
8 | With the automatic power-saving, the driver turns off the codec power | 9 | With the automatic power-saving, the driver turns off the codec power |
9 | appropriately when no operation is required. When no applications use | 10 | appropriately when no operation is required. When no applications use |
@@ -11,20 +12,21 @@ the device and/or no analog loopback is set, the power disablement is | |||
11 | done fully or partially. It'll save a certain power consumption, thus | 12 | done fully or partially. It'll save a certain power consumption, thus |
12 | good for laptops (even for desktops). | 13 | good for laptops (even for desktops). |
13 | 14 | ||
14 | The time-out for automatic power-off can be specified via power_save | 15 | The time-out for automatic power-off can be specified via ``power_save`` |
15 | module option of snd-ac97-codec and snd-hda-intel modules. Specify | 16 | module option of snd-ac97-codec and snd-hda-intel modules. Specify |
16 | the time-out value in seconds. 0 means to disable the automatic | 17 | the time-out value in seconds. 0 means to disable the automatic |
17 | power-saving. The default value of timeout is given via | 18 | power-saving. The default value of timeout is given via |
18 | CONFIG_SND_AC97_POWER_SAVE_DEFAULT and | 19 | ``CONFIG_SND_AC97_POWER_SAVE_DEFAULT`` and |
19 | CONFIG_SND_HDA_POWER_SAVE_DEFAULT Kconfig options. Setting this to 1 | 20 | ``CONFIG_SND_HDA_POWER_SAVE_DEFAULT`` Kconfig options. Setting this to 1 |
20 | (the minimum value) isn't recommended because many applications try to | 21 | (the minimum value) isn't recommended because many applications try to |
21 | reopen the device frequently. 10 would be a good choice for normal | 22 | reopen the device frequently. 10 would be a good choice for normal |
22 | operations. | 23 | operations. |
23 | 24 | ||
24 | The power_save option is exported as writable. This means you can | 25 | The ``power_save`` option is exported as writable. This means you can |
25 | adjust the value via sysfs on the fly. For example, to turn on the | 26 | adjust the value via sysfs on the fly. For example, to turn on the |
26 | automatic power-save mode with 10 seconds, write to | 27 | automatic power-save mode with 10 seconds, write to |
27 | /sys/modules/snd_ac97_codec/parameters/power_save (usually as root): | 28 | ``/sys/modules/snd_ac97_codec/parameters/power_save`` (usually as root): |
29 | :: | ||
28 | 30 | ||
29 | # echo 10 > /sys/modules/snd_ac97_codec/parameters/power_save | 31 | # echo 10 > /sys/modules/snd_ac97_codec/parameters/power_save |
30 | 32 | ||