ALSA: hda - Add description about patch loading

Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2009-06-17 17:17:18 +02:00
parent 4ea6fbc8eb
commit 7682482563
1 changed files with 46 additions and 0 deletions

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@ -403,6 +403,52 @@ re-configure based on that state, run like below:
------------------------------------------------------------------------
Early Patching
~~~~~~~~~~~~~~
When CONFIG_SND_HDA_PATCH_LOADER=y is set, you can pass a "patch" as a
firmware file for modifying the HD-audio setup before initializing the
codec. This can work basically like the reconfiguration via sysfs in
the above, but it does it before the first codec configuration.
The patch file looks like below:
------------------------------------------------------------------------
[codec]
0x12345678 0xabcd1234 2
[model]
auto
[pincfg]
0x12 0x411111f0
[verb]
0x20 0x500 0x03
0x20 0x400 0xff
[hint]
hp_detect = yes
------------------------------------------------------------------------
The file needs to have a line `[codec]`. The next line should contain
three numbers indicating the codec vendor-id (0x12345678 in the
example), the codec subsystem-id (0xabcd1234) and the address (2) of
the codec. The rest patch entries are applied to this specified codec
until another codec entry is given.
The `[model]` line allows to change the model name of the each codec.
In the example above, it will be changed to model=auto.
Note that this overrides the module option.
After the `[pincfg]` line, the contents are parsed as the initial
default pin-configurations just like `user_pin_configs` sysfs above.
The values can be shown in user_pin_configs sysfs file, too.
Similarly, the lines after `[verb]` are parsed as `init_verbs`
sysfs entries, and the lines after `[hint]` are parsed as `hints`
sysfs entries, respectively.
Power-Saving
~~~~~~~~~~~~
The power-saving is a kind of auto-suspend of the device. When the