From 1604f51b401bfd881ab5c6401eaedac97f2166ca Mon Sep 17 00:00:00 2001 From: Ivan Orlov Date: Mon, 1 May 2023 14:16:34 +0400 Subject: ALSA: docs: Extend module parameters description Common ALSA module parameters look a little bit confusing because of the description lacking, and it took me a while to understand the purpose of their existence. To figure it out I asked the question about them to the "alsa-devel" mailing list, and Takashi Iwai answered me with the text I appended to the ALSA documentation in this patch. These common module parameters aren't used a lot nowadays, but as I understand they are important for providing compatibility with some existing user-space apps. So in my opinion it is a good idea to document why we need them. Signed-off-by: Ivan Orlov Link: https://lore.kernel.org/r/20230501101634.476297-1-ivan.orlov0322@gmail.com Signed-off-by: Takashi Iwai --- Documentation/sound/alsa-configuration.rst | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'Documentation') diff --git a/Documentation/sound/alsa-configuration.rst b/Documentation/sound/alsa-configuration.rst index af71c68f1e4e..829c672d9fe6 100644 --- a/Documentation/sound/alsa-configuration.rst +++ b/Documentation/sound/alsa-configuration.rst @@ -133,6 +133,19 @@ enable enable card; Default: enabled, for PCI and ISA PnP cards +These options are used for either specifying the order of instances or +controlling enabling and disabling of each one of the devices if there +are multiple devices bound with the same driver. For example, there are +many machines which have two HD-audio controllers (one for HDMI/DP +audio and another for onboard analog). In most cases, the second one is +in primary usage, and people would like to assign it as the first +appearing card. They can do it by specifying "index=1,0" module +parameter, which will swap the assignment slots. + +Today, with the sound backend like PulseAudio and PipeWire which +supports dynamic configuration, it's of little use, but that was a +help for static configuration in the past. + Module snd-adlib ---------------- -- cgit From e4212ed0ba58264fbe7706c5493b9600339f60ae Mon Sep 17 00:00:00 2001 From: Bagas Sanjaya Date: Wed, 3 May 2023 10:54:16 +0700 Subject: ALSA: docs: Fix code block indentation in ALSA driver example Sphinx reports htmldocs warnings: Documentation/sound/kernel-api/writing-an-alsa-driver.rst:3997: WARNING: Literal block expected; none found. Documentation/sound/kernel-api/writing-an-alsa-driver.rst:4004: WARNING: Literal block expected; none found. Documentation/sound/kernel-api/writing-an-alsa-driver.rst:4009: WARNING: Unexpected indentation. Documentation/sound/kernel-api/writing-an-alsa-driver.rst:4035: WARNING: Literal block expected; none found. These are due to indentation of example driver snippets which is outside the code block scope. Fix these by indenting code blocks in question to the scope. Fixes: 4d421eebe1465d ("ALSA: docs: writing-an-alsa-driver.rst: polishing") Reported-by: kernel test robot Closes: https://lore.kernel.org/linux-doc/202305021822.4U6XOvGf-lkp@intel.com/ Signed-off-by: Bagas Sanjaya Link: https://lore.kernel.org/r/20230503035416.62722-1-bagasdotme@gmail.com Signed-off-by: Takashi Iwai --- .../sound/kernel-api/writing-an-alsa-driver.rst | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) (limited to 'Documentation') diff --git a/Documentation/sound/kernel-api/writing-an-alsa-driver.rst b/Documentation/sound/kernel-api/writing-an-alsa-driver.rst index c0f97b5e4249..4335c98b3d82 100644 --- a/Documentation/sound/kernel-api/writing-an-alsa-driver.rst +++ b/Documentation/sound/kernel-api/writing-an-alsa-driver.rst @@ -3994,21 +3994,21 @@ Driver with A Single Source File Suppose you have a file xyz.c. Add the following two lines:: - snd-xyz-objs := xyz.o - obj-$(CONFIG_SND_XYZ) += snd-xyz.o + snd-xyz-objs := xyz.o + obj-$(CONFIG_SND_XYZ) += snd-xyz.o 2. Create the Kconfig entry Add the new entry of Kconfig for your xyz driver:: - config SND_XYZ - tristate "Foobar XYZ" - depends on SND - select SND_PCM - help - Say Y here to include support for Foobar XYZ soundcard. - To compile this driver as a module, choose M here: - the module will be called snd-xyz. + config SND_XYZ + tristate "Foobar XYZ" + depends on SND + select SND_PCM + help + Say Y here to include support for Foobar XYZ soundcard. + To compile this driver as a module, choose M here: + the module will be called snd-xyz. The line ``select SND_PCM`` specifies that the driver xyz supports PCM. In addition to SND_PCM, the following components are supported for @@ -4032,7 +4032,7 @@ located in the new subdirectory, sound/pci/xyz. 1. Add a new directory (``sound/pci/xyz``) in ``sound/pci/Makefile`` as below:: - obj-$(CONFIG_SND) += sound/pci/xyz/ + obj-$(CONFIG_SND) += sound/pci/xyz/ 2. Under the directory ``sound/pci/xyz``, create a Makefile:: -- cgit