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1	<?xml version='1.0' encoding="UTF-8"?>	1	<?xml version='1.0' encoding="UTF-8"?>
2	<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/alsa-guide.xml,v 1.57 2005/07/14 19:22:54 fox2mike Exp $ -->	2	<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/alsa-guide.xml,v 1.66 2006/05/01 05:52:31 fox2mike Exp $ -->
3		3
4	<!DOCTYPE guide SYSTEM "/dtd/guide.dtd">	4	<!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
5		5
6	<guide link="/doc/en/alsa-guide.xml">	6	<guide link="/doc/en/alsa-guide.xml">
7	<title>Gentoo Linux ALSA Guide</title>	7	<title>Gentoo Linux ALSA Guide</title>
…		…
16		16
17	<!-- The content of this document is licensed under the CC-BY-SA license -->	17	<!-- The content of this document is licensed under the CC-BY-SA license -->
18	<!-- See http://creativecommons.org/licenses/by-sa/2.5 -->	18	<!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
19	<license/>	19	<license/>
20		20
21	<version>2.6</version>	21	<version>2.12</version>
22	<date>2005-07-14</date>	22	<date>2006-05-01</date>
23		23
24	<chapter>	24	<chapter>
25	<title>Introduction</title>	25	<title>Introduction</title>
26	<section>	26	<section>
27	<title>What is ALSA?</title>	27	<title>What is ALSA?</title>
…		…
83	<li>	83	<li>
84	Use Gentoo's <c>media-sound/alsa-driver</c> package.	84	Use Gentoo's <c>media-sound/alsa-driver</c> package.
85	</li>	85	</li>
86	</ol>	86	</ol>
87		87
88	<p>	88	<p>
89	We shall take a peek into both before finally deciding on one.	89	We shall take a peek into both before finally deciding on one.
90	</p>	90	</p>
91		91
92	<p>	92	<p>
93	If you were to use ALSA provided by the kernel, the following are the pros and	93	If you were to use ALSA provided by the kernel, the following are the pros and
…		…
231	<p>	231	<p>
232	Let us now configure the kernel to enable ALSA.	232	Let us now configure the kernel to enable ALSA.
233	</p>	233	</p>
234		234
235	<impo>	235	<impo>
236	<c>genkernel</c> users should now run <c>genkernel --menuconfig</c> and then follow	236	<c>genkernel</c> users should now run <c>genkernel --menuconfig all</c> and
237	the instructions in <uri link="#doc_chap2_pre3">Kernel Options for ALSA</uri>.	237	then follow the instructions in <uri link="#doc_chap2_pre3">Kernel Options for
		238	ALSA</uri>.
238	</impo>	239	</impo>
239		240
240	<pre caption="Heading over to the source">	241	<pre caption="Heading over to the source">
241	# <i>cd /usr/src/linux</i>	242	# <i>cd /usr/src/linux</i>
242	# <i>make menuconfig</i>	243	# <i>make menuconfig</i>
…		…
253	</p>	254	</p>
254		255
255	<p>	256	<p>
256	Please note that for the sake of ease, all examples show ALSA built as modules.	257	Please note that for the sake of ease, all examples show ALSA built as modules.
257	It is advisable to follow the same as it then allows the use of <c>alsaconf</c>	258	It is advisable to follow the same as it then allows the use of <c>alsaconf</c>
258	which is a boon when you want to configure your card. Please do <e>not</e> skip the <uri	259	which is a boon when you want to configure your card. Please do <e>not</e> skip
259	link="#alsa-config">Configuration</uri> section of this document. If you still	260	the <uri link="#alsa-config">Configuration</uri> section of this document. If
260	like to have options built-in, ensure that you make changes to your config	261	you still like to have options built-in, ensure that you make changes to your
261	accordingly.	262	config accordingly.
262	</p>	263	</p>
263		264
264	<pre caption="Kernel Options for ALSA">	265	<pre caption="Kernel Options for ALSA">
265	Device Drivers --->	266	Device Drivers --->
266	Sound --->	267	Sound --->
…		…
308	USB Devices --->	309	USB Devices --->
309	</pre>	310	</pre>
310		311
311	<p>	312	<p>
312	Now that your options are set, you can (re)compile the kernel and ALSA support	313	Now that your options are set, you can (re)compile the kernel and ALSA support
313	for your card should be functional once you reboot into the new kernel.	314	for your card should be functional once you reboot into the new kernel. Don't
		315	forget to update your GRUB configuration to use the newly built kernel.
314	You can now proceed to <uri link="#alsa-utilities">ALSA Utilities</uri> and	316	You can now proceed to <uri link="#alsa-utilities">ALSA Utilities</uri> and
315	see if everything is working as it should.	317	see if everything is working as it should.
316	</p>	318	</p>
317		319
318	</body>	320	</body>
…		…
336	</p>	338	</p>
337		339
338	<pre caption="Adding ALSA_CARDS to make.conf">	340	<pre caption="Adding ALSA_CARDS to make.conf">
339	<comment>(For one sound card)</comment>	341	<comment>(For one sound card)</comment>
340	ALSA_CARDS="emu10k1"	342	ALSA_CARDS="emu10k1"
341	<comment>(For more than one, seperate names with spaces)</comment>	343	<comment>(For more than one, separate names with spaces)</comment>
342	ALSA_CARDS="emu10k1 via82xx"	344	ALSA_CARDS="emu10k1 via82xx"
343	</pre>	345	</pre>
344		346
345	<p>	347	<p>
346	If you have compiled your kernel and want to use <c>alsa-driver</c>, please	348	If you have compiled your kernel and want to use <c>alsa-driver</c>, please
…		…
448	your devices and try to find out your sound card. You will be asked to pick	450	your devices and try to find out your sound card. You will be asked to pick
449	your sound card from a list. Once that's done, it will ask you permission to	451	your sound card from a list. Once that's done, it will ask you permission to
450	automatically make required changes to <path>/etc/modules.d/alsa</path>.	452	automatically make required changes to <path>/etc/modules.d/alsa</path>.
451	It will then adjust your volume settings to optimum levels, run	453	It will then adjust your volume settings to optimum levels, run
452	<c>modules-update</c> and start the <path>/etc/init.d/alsasound</path> service.	454	<c>modules-update</c> and start the <path>/etc/init.d/alsasound</path> service.
453	Once <c>alsaconf</c> exits, you can proceed with setting up the ALSA initscript.	455	Once <c>alsaconf</c> exits, you can proceed with setting up the ALSA
		456	initscript.
454	</p>	457	</p>
455		458
456	</body>	459	</body>
457	</section>	460	</section>
458	<section id="initscript">	461	<section id="initscript">
…		…
487	<p>	490	<p>
488	Before we move on to testing, there's one last <e>important</e> thing that needs	491	Before we move on to testing, there's one last <e>important</e> thing that needs
489	to be setup. Rule of thumb in a *nix OS : Do not run as root unless needed.	492	to be setup. Rule of thumb in a *nix OS : Do not run as root unless needed.
490	This applies here as well ;) How? Well, most of the times you should be logged	493	This applies here as well ;) How? Well, most of the times you should be logged
491	in as a user and would like to listen to music or access your soundcard. For	494	in as a user and would like to listen to music or access your soundcard. For
492	that to happen, you need to be in the "audio" group. At this point, we'll add	495	that to happen, you need to be in the "audio" group. At this point, we'll add
493	users to the audio group, so that they won't have any issues when they want to	496	users to the audio group, so that they won't have any issues when they want to
494	access sound devices. We'll use <c>gpasswd</c> here and you need to be logged in	497	access sound devices. We'll use <c>gpasswd</c> here and you need to be logged in
495	as root for this to work.	498	as root for this to work.
496	</p>	499	</p>
497		500
…		…
517	<comment>(ALSA as modules)</comment>	520	<comment>(ALSA as modules)</comment>
518	# <i>/etc/init.d/alsasound start</i>	521	# <i>/etc/init.d/alsasound start</i>
519	* Loading ALSA modules ...	522	* Loading ALSA modules ...
520	* Loading: snd-card-0 ... [ ok ]	523	* Loading: snd-card-0 ... [ ok ]
521	* Loading: snd-pcm-oss ... [ ok ]	524	* Loading: snd-pcm-oss ... [ ok ]
522	* Loading: snd-seq ... [ ok ]	525	* Loading: snd-seq ... [ ok ]
523	* Loading: snd-emu10k1-synth ... [ ok ]	526	* Loading: snd-emu10k1-synth ... [ ok ]
524	* Loading: snd-seq-midi ... [ ok ]	527	* Loading: snd-seq-midi ... [ ok ]
525	* Restoring Mixer Levels ... [ ok ]	528	* Restoring Mixer Levels ... [ ok ]
526	<comment>(ALSA compiled in)</comment>	529	<comment>(ALSA compiled in)</comment>
527	# <i>/etc/init.d/alsasound start</i>	530	# <i>/etc/init.d/alsasound start</i>
528	* Loading ALSA modules ...	531	* Loading ALSA modules ...
529	* Restoring Mixer Levels ... [ ok ]	532	* Restoring Mixer Levels ... [ ok ]
…		…
541	</pre>	544	</pre>
542		545
543	<impo>	546	<impo>
544	If you have issues starting up <c>alsamixer</c> and get errors such as	547	If you have issues starting up <c>alsamixer</c> and get errors such as
545	alsamixer: function snd_ctl_open failed for default: No such file or directory,	548	alsamixer: function snd_ctl_open failed for default: No such file or directory,
546	this is usually an issue with udev setting up the devices. Run <c>killall -9	549	this is usually an issue with udev setting up the devices. Run <c>killall
547	udevd; udevstart</c> to reload /dev entries and fire up <c>alsamixer</c>. It	550	udevd; udevstart</c> to reload <path>/dev</path> entries and fire up
548	should solve the issue.	551	<c>alsamixer</c>. It should solve the issue.
549	</impo>	552	</impo>
550		553
551	<p>	554	<p>
552	This is how the ALSA Mixer <e>might</e> look the first time you open it. Pay	555	This is how the ALSA Mixer <e>might</e> look the first time you open it. Pay
553	attention to the Master and PCM channels which both have an MM below them.	556	attention to the Master and PCM channels which both have an MM below them.
…		…
598	</body>	601	</body>
599	</section>	602	</section>
600	<section>	603	<section>
601	<title>Sound Check!</title>	604	<title>Sound Check!</title>
602	<body>	605	<body>
603
604	<p>
605	The irritating way to check your soundcard is to see if you can hear static on
606	the speakers. This isn't exactly fun, but hey, it tells you the card is
607	configured and working.
608	</p>
609
610	<pre caption="Bring on th static">
611	# <i>cat /dev/urandom > /dev/dsp</i>
612	</pre>
613
614	<note>
615	<path>/dev/dsp</path> is a symlink to <path>/dev/sound/dsp</path> and should be
616	automatically created. Try re-directing the output to
617	<path>/dev/sound/dsp</path> in case you don't get a "No such file or directory"
618	error.
619	</note>
620
621	<p>
622	You should hear static. Press <c>Ctrl + C</c> to stop. If you don't hear
623	anything, now is a good time to go back and check/trace out the issue and
624	rectify it.
625	</p>
626		606
627	<p>	607	<p>
628	Finally. Some music. If everything above is perfect, you should now be able to	608	Finally. Some music. If everything above is perfect, you should now be able to
629	listen to some good music. A quick way to test is to use a command line tool	609	listen to some good music. A quick way to test is to use a command line tool
630	like <c>media-sound/madplay</c>. You could also use something more well known	610	like <c>media-sound/madplay</c>. You could also use something more well known
…		…
670	</pre>	650	</pre>
671		651
672	</body>	652	</body>
673	</section>	653	</section>
674	<section>	654	<section>
675	<title> ALSA and USE</title>	655	<title>ALSA and USE</title>
676	<body>	656	<body>
677		657
678	<p>	658	<p>
679	You can now add the <c>alsa</c> use flag to <path>/etc/make.conf</path> to	659	You can now add the <c>alsa</c> use flag to <path>/etc/make.conf</path> to
680	ensure that your applications that support ALSA get built with it. Some	660	ensure that your applications that support ALSA get built with it. Some
…		…
737		717
738	Mixers:	718	Mixers:
739	0: SigmaTel STAC9721/23	719	0: SigmaTel STAC9721/23
740	</pre>	720	</pre>
741		721
		722	<p>
		723	The other most common issue users face is the dreaded "Unknown symbol in module"
		724	error. An example of the same is shown below.
		725	</p>
		726
		727	<pre caption="Unknown Symbol in module error">
		728	# <i>/etc/init.d/alsasound start</i>
		729	* Loading ALSA modules ...
		730	* Loading: snd-card-0 ... [ ok ]
		731	* Loading: snd-pcm-oss ...
		732	WARNING: Error inserting snd_mixer_oss
		733	(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-mixer-oss.ko): Unknown
		734	symbol in module, or unknown parameter (see dmesg) FATAL: Error inserting
		735	snd_pcm_oss
		736	(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-pcm-oss.ko): Unknown
		737	symbol in module, or unknown parameter (see dmesg)
		738	[ !! ]
		739	* Loading: snd-mixer-oss ...
		740	FATAL: Error inserting snd_mixer_oss
		741	(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-mixer-oss.ko): Unknown
		742	symbol in module, or unknown parameter (see dmesg)
		743	[ !! ]
		744	* Loading: snd-seq ... [ ok ]
		745	* Loading: snd-emu10k1-synth ... [ ok ]
		746	* Loading: snd-seq-midi ... [ ok ]
		747	* Restoring Mixer Levels ... [ ok ]
		748	</pre>
		749
		750	<p>
		751	And when you take a look at <c>dmesg</c> as suggested, you're quite likely to
		752	see:
		753	</p>
		754
		755	<pre caption="dmesg output">
		756	<comment>(Only relevant portions are shown below)</comment>
		757	# <i>dmesg \| less</i>
		758	ACPI: PCI Interrupt 0000:02:06.0[A] -> Link [APC3] -> GSI 18 (level, low) -> IRQ 209
		759	snd_mixer_oss: Unknown symbol snd_unregister_oss_device
		760	snd_mixer_oss: Unknown symbol snd_register_oss_device
		761	snd_mixer_oss: Unknown symbol snd_mixer_oss_notify_callback
		762	snd_mixer_oss: Unknown symbol snd_oss_info_register
		763	snd_pcm_oss: Unknown symbol snd_unregister_oss_device
		764	snd_pcm_oss: Unknown symbol snd_register_oss_device
		765	snd_pcm_oss: Unknown symbol snd_mixer_oss_ioctl_card
		766	snd_pcm_oss: Unknown symbol snd_oss_info_register
		767	snd_mixer_oss: Unknown symbol snd_unregister_oss_device
		768	snd_mixer_oss: Unknown symbol snd_register_oss_device
		769	snd_mixer_oss: Unknown symbol snd_mixer_oss_notify_callback
		770	snd_mixer_oss: Unknown symbol snd_oss_info_register
		771	</pre>
		772
		773	<p>
		774	The above issue is caused when you switch from <c>alsa-driver</c> to in-kernel
		775	ALSA because when you unmerge <c>alsa-driver</c> the module files are config
		776	protected and hence get left behind. So, when you switch to in-kernel
		777	drivers, running <c>modprobe</c> gives you a mix of <c>alsa-driver</c> and
		778	in-kernel modules thus causing the above errors.
		779	</p>
		780
		781	<p>
		782	The solution is quite easy. We just need to manually remove the problem causing
		783	directory after you unmerge <c>alsa-driver</c>. Be sure to remove the correct
		784	kernel version and not the current one!
		785	</p>
		786
		787	<pre caption="Removing the alsa-driver modules">
		788	<comment>(Replace KERNELVER with your kernel version)</comment>
		789	# <i>rm -rf /lib/modules/KERNELVER/alsa-driver</i>
		790	</pre>
		791
		792	<p>
		793	Another reason for error messages similar to the ones above could be a file in
		794	<path>/etc/modules.d</path> supplying a <c>device_node</c> parameter when it
		795	isn't required. Confirm that this is indeed the issue and find out which file
		796	is the culprit.
		797	</p>
		798
		799	<pre caption="Confirming and searching for device_node">
		800	<comment>(Check dmesg to confirm)</comment>
		801	# <i>dmesg \| grep device_mode</i>
		802	snd: Unknown parameter `device_mode'
		803	<comment>(Now, to get to the source of the issue)</comment>
		804	# <i>grep device_mode /etc/modules.d/*</i>
		805	</pre>
		806
		807	<p>
		808	Usually it is a file called <path>alsa</path> with the line <c>options snd
		809	device_mode=0666</c>. Remove this line and restart the alsasound service and
		810	that should take care of this issue.
		811	</p>
		812
742	</body>	813	</body>
743	</section>	814	</section>
744	</chapter>	815	</chapter>
745		816
746	<chapter>	817	<chapter>
…		…
781	change the path to suit your machine.	852	change the path to suit your machine.
782	</note>	853	</note>
783		854
784	<pre caption="Loading Soundfonts">	855	<pre caption="Loading Soundfonts">
785	<comment>(First, copy the Soundfont)</comment>	856	<comment>(First, copy the Soundfont)</comment>
786	# <i>cp /mnt/win2k/Program\ Files/CreativeSBLive2k/SFBank/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>	857	# <i>cp /mnt/win2k/Program\ Files/CreativeSBLive2k/SFBank/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
		858	<comment>(Or get it from your SoundBlaster CD)</comment>
		859	# <i>cp /mnt/cdrom/AUDIO/ENGLISH/SFBANK/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
787	<comment>(We load the specific Soundfont)</comment>	860	<comment>(We load the specific Soundfont)</comment>
788	# <i>asfxload /usr/share/sounds/sf2/8MBGMSFX.SF2</i>	861	# <i>asfxload /usr/share/sounds/sf2/8MBGMSFX.SF2</i>
789	</pre>	862	</pre>
790		863
791	<p>	864	<p>

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