ALSA: hda - More description about patch module option (1e7b8c87) · Commits · e / devices / android_kernel_xiaomi_markw

Documentation/sound/alsa/ALSA-Configuration.txt

+4 −0

Original line number	Diff line number	Diff line
		@@ -749,6 +749,10 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
		bdl_pos_adj - Specifies the DMA IRQ timing delay in samples.
		Passing -1 will make the driver to choose the appropriate
		value based on the controller chip.
		patch - Specifies the early "patch" files to modify the HD-audio
		setup before initializing the codecs. This option is
		available only when CONFIG_SND_HDA_PATCH_LOADER=y is set.
		See HD-Audio.txt for details.

		[Single (global) options]
		single_cmd - Use single immediate commands to communicate with

+15 −1

Original line number	Diff line number	Diff line
		@@ -410,7 +410,7 @@ 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:
		A patch file is a plain text file which looks like below:

		------------------------------------------------------------------------
		[codec]
		@@ -448,6 +448,20 @@ Similarly, the lines after `[verb]` are parsed as `init_verbs`
		sysfs entries, and the lines after `[hint]` are parsed as `hints`
		sysfs entries, respectively.

		The hd-audio driver reads the file via request_firmware(). Thus,
		a patch file has to be located on the appropriate firmware path,
		typically, /lib/firmware. For example, when you pass the option
		`patch=hda-init.fw`, the file /lib/firmware/hda-init-fw must be
		present.

		The patch module option is specific to each card instance, and you
		need to give one file name for each instance, separated by commas.
		For example, if you have two cards, one for an on-board analog and one
		for an HDMI video board, you may pass patch option like below:
		------------------------------------------------------------------------
		options snd-hda-intel patch=on-board-patch,hdmi-patch
		------------------------------------------------------------------------


		Power-Saving
		~~~~~~~~~~~~