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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 1.56 2005/07/14 09:11:02 neysx Exp $ -->	2	<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/alsa-guide.xml,v 1.69 2006/07/07 14:40:08 rane 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>2.5</version>	21	<version>2.14</version>
22	<date>2005-07-14</date>	22	<date>2006-07-06</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
…		…
144		144
145	<p>	145	<p>
146	The main difference between using <c>alsa-driver</c> and ALSA that comes with	146	The main difference between using <c>alsa-driver</c> and ALSA that comes with
147	the kernel is that <c>alsa-driver</c> is generally more up to date than the	147	the kernel is that <c>alsa-driver</c> is generally more up to date than the
148	version in the kernel. Since this does not make any huge difference as	148	version in the kernel. Since this does not make any huge difference as
149	such, you are encouraged to use the ALSA provided by the kernel.	149	such, you are encouraged to use the ALSA provided by the kernel for ease of use.
		150	Before reporting any sound related issues to <uri
		151	link="https://bugs.gentoo.org">Gentoo Bugzilla</uri>, please try to reproduce
		152	them using <c>alsa-driver</c> and file the bug report no matter what the
		153	result.
150	</p>	154	</p>
151		155
152	</body>	156	</body>
153	</section>	157	</section>
154	<section id="lspci">	158	<section id="lspci">
…		…
227	<p>	231	<p>
228	Let us now configure the kernel to enable ALSA.	232	Let us now configure the kernel to enable ALSA.
229	</p>	233	</p>
230		234
231	<impo>	235	<impo>
232	<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
233	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>.
234	</impo>	239	</impo>
235		240
236	<pre caption="Heading over to the source">	241	<pre caption="Heading over to the source">
237	# <i>cd /usr/src/linux</i>	242	# <i>cd /usr/src/linux</i>
238	# <i>make menuconfig</i>	243	# <i>make menuconfig</i>
…		…
249	</p>	254	</p>
250		255
251	<p>	256	<p>
252	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.
253	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>
254	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
255	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
256	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
257	accordingly.	262	config accordingly.
258	</p>	263	</p>
259		264
260	<pre caption="Kernel Options for ALSA">	265	<pre caption="Kernel Options for ALSA">
261	Device Drivers --->	266	Device Drivers --->
262	Sound --->	267	Sound --->
…		…
304	USB Devices --->	309	USB Devices --->
305	</pre>	310	</pre>
306		311
307	<p>	312	<p>
308	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
309	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.
310	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
311	see if everything is working as it should.	317	see if everything is working as it should.
312	</p>	318	</p>
313		319
314	</body>	320	</body>
…		…
332	</p>	338	</p>
333		339
334	<pre caption="Adding ALSA_CARDS to make.conf">	340	<pre caption="Adding ALSA_CARDS to make.conf">
335	<comment>(For one sound card)</comment>	341	<comment>(For one sound card)</comment>
336	ALSA_CARDS="emu10k1"	342	ALSA_CARDS="emu10k1"
337	<comment>(For more than one, seperate names with spaces)</comment>	343	<comment>(For more than one, separate names with spaces)</comment>
338	ALSA_CARDS="emu10k1 via82xx"	344	ALSA_CARDS="emu10k1 via82xx"
339	</pre>	345	</pre>
340		346
341	<p>	347	<p>
342	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
…		…
444	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
445	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
446	automatically make required changes to <path>/etc/modules.d/alsa</path>.	452	automatically make required changes to <path>/etc/modules.d/alsa</path>.
447	It will then adjust your volume settings to optimum levels, run	453	It will then adjust your volume settings to optimum levels, run
448	<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.
449	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.
450	</p>	457	</p>
451		458
452	</body>	459	</body>
453	</section>	460	</section>
454	<section id="initscript">	461	<section id="initscript">
…		…
483	<p>	490	<p>
484	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
485	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.
486	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
487	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
488	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
489	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
490	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
491	as root for this to work.	498	as root for this to work.
492	</p>	499	</p>
493		500
…		…
513	<comment>(ALSA as modules)</comment>	520	<comment>(ALSA as modules)</comment>
514	# <i>/etc/init.d/alsasound start</i>	521	# <i>/etc/init.d/alsasound start</i>
515	* Loading ALSA modules ...	522	* Loading ALSA modules ...
516	* Loading: snd-card-0 ... [ ok ]	523	* Loading: snd-card-0 ... [ ok ]
517	* Loading: snd-pcm-oss ... [ ok ]	524	* Loading: snd-pcm-oss ... [ ok ]
518	* Loading: snd-seq ... [ ok ]	525	* Loading: snd-seq ... [ ok ]
519	* Loading: snd-emu10k1-synth ... [ ok ]	526	* Loading: snd-emu10k1-synth ... [ ok ]
520	* Loading: snd-seq-midi ... [ ok ]	527	* Loading: snd-seq-midi ... [ ok ]
521	* Restoring Mixer Levels ... [ ok ]	528	* Restoring Mixer Levels ... [ ok ]
522	<comment>(ALSA compiled in)</comment>	529	<comment>(ALSA compiled in)</comment>
523	# <i>/etc/init.d/alsasound start</i>	530	# <i>/etc/init.d/alsasound start</i>
524	* Loading ALSA modules ...	531	* Loading ALSA modules ...
525	* Restoring Mixer Levels ... [ ok ]	532	* Restoring Mixer Levels ... [ ok ]
…		…
537	</pre>	544	</pre>
538		545
539	<impo>	546	<impo>
540	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
541	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,
542	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
543	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
544	should solve the issue.	551	<c>alsamixer</c>. It should solve the issue.
545	</impo>	552	</impo>
546		553
547	<p>	554	<p>
548	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
549	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.
…		…
594	</body>	601	</body>
595	</section>	602	</section>
596	<section>	603	<section>
597	<title>Sound Check!</title>	604	<title>Sound Check!</title>
598	<body>	605	<body>
599
600	<p>
601	The irritating way to check your soundcard is to see if you can hear static on
602	the speakers. This isn't exactly fun, but hey, it tells you the card is
603	configured and working.
604	</p>
605
606	<pre caption="Bring on th static">
607	# <i>cat /dev/urandom > /dev/dsp</i>
608	</pre>
609
610	<note>
611	<path>/dev/dsp</path> is a symlink to <path>/dev/sound/dsp</path> and should be
612	automatically created. Try re-directing the output to
613	<path>/dev/sound/dsp</path> in case you don't get a "No such file or directory"
614	error.
615	</note>
616
617	<p>
618	You should hear static. Press <c>Ctrl + C</c> to stop. If you don't hear
619	anything, now is a good time to go back and check/trace out the issue and
620	rectify it.
621	</p>
622		606
623	<p>	607	<p>
624	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
625	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
626	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
…		…
666	</pre>	650	</pre>
667		651
668	</body>	652	</body>
669	</section>	653	</section>
670	<section>	654	<section>
671	<title> ALSA and USE</title>	655	<title>ALSA and USE</title>
672	<body>	656	<body>
673		657
674	<p>	658	<p>
675	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
676	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
…		…
733		717
734	Mixers:	718	Mixers:
735	0: SigmaTel STAC9721/23	719	0: SigmaTel STAC9721/23
736	</pre>	720	</pre>
737		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	# <i>rm -rf /lib/modules/$(uname -r)/alsa-driver</i>
		789	</pre>
		790
		791	<p>
		792	Another reason for error messages similar to the ones above could be a file in
		793	<path>/etc/modules.d</path> supplying a <c>device_mode</c> parameter when it
		794	isn't required. Confirm that this is indeed the issue and find out which file
		795	is the culprit.
		796	</p>
		797
		798	<pre caption="Confirming and searching for device_mode">
		799	<comment>(Check dmesg to confirm)</comment>
		800	# <i>dmesg \| grep device_mode</i>
		801	snd: Unknown parameter `device_mode'
		802	<comment>(Now, to get to the source of the issue)</comment>
		803	# <i>grep device_mode /etc/modules.d/*</i>
		804	</pre>
		805
		806	<p>
		807	Usually it is a file called <path>alsa</path> with the line <c>options snd
		808	device_mode=0666</c>. Remove this line and restart the alsasound service and
		809	that should take care of this issue.
		810	</p>
		811
738	</body>	812	</body>
739	</section>	813	</section>
740	</chapter>	814	</chapter>
741		815
742	<chapter>	816	<chapter>
…		…
777	change the path to suit your machine.	851	change the path to suit your machine.
778	</note>	852	</note>
779		853
780	<pre caption="Loading Soundfonts">	854	<pre caption="Loading Soundfonts">
781	<comment>(First, copy the Soundfont)</comment>	855	<comment>(First, copy the Soundfont)</comment>
782	# <i>cp /mnt/win2k/Program\ Files/CreativeSBLive2k/SFBank/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>	856	# <i>cp /mnt/win2k/Program\ Files/CreativeSBLive2k/SFBank/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
		857	<comment>(Or get it from your SoundBlaster CD)</comment>
		858	# <i>cp /mnt/cdrom/AUDIO/ENGLISH/SFBANK/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
783	<comment>(We load the specific Soundfont)</comment>	859	<comment>(We load the specific Soundfont)</comment>
784	# <i>asfxload /usr/share/sounds/sf2/8MBGMSFX.SF2</i>	860	# <i>asfxload /usr/share/sounds/sf2/8MBGMSFX.SF2</i>
785	</pre>	861	</pre>
786		862
787	<p>	863	<p>

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