1Introduction Notes on Modular Sound Drivers and Soundcore 2Wade Hampton 32/14/2001 4 5Purpose: 6======== 7This document provides some general notes on the modular 8sound drivers and their configuration, along with the 9support modules sound.o and soundcore.o. 10 11Note, some of this probably should be added to the Sound-HOWTO! 12 13Note, soundlow.o was present with 2.2 kernels but is not 14required for 2.4.x kernels. References have been removed 15to this. 16 17 18Copying: 19======== 20none 21 22 23History: 24======== 250.1.0 11/20/1998 First version, draft 261.0.0 11/1998 Alan Cox changes, incorporation in 2.2.0 27 as Documentation/sound/oss/Introduction 281.1.0 6/30/1999 Second version, added notes on making the drivers, 29 added info on multiple sound cards of similar types,] 30 added more diagnostics info, added info about esd. 31 added info on OSS and ALSA. 321.1.1 19991031 Added notes on sound-slot- and sound-service. 33 (Alan Cox) 341.1.2 20000920 Modified for Kernel 2.4 (Christoph Hellwig) 351.1.3 20010214 Minor notes and corrections (Wade Hampton) 36 Added examples of sound-slot-0, etc. 37 38 39Modular Sound Drivers: 40====================== 41 42Thanks to the GREAT work by Alan Cox (alan@lxorguk.ukuu.org.uk), 43 44[And Oleg Drokin, Thomas Sailer, Andrew Veliath and more than a few 45 others - not to mention Hannu's original code being designed well 46 enough to cope with that kind of chopping up](Alan) 47 48the standard Linux kernels support a modular sound driver. From 49Alan's comments in linux/drivers/sound/README.FIRST: 50 51 The modular sound driver patches were funded by Red Hat Software 52 (www.redhat.com). The sound driver here is thus a modified version of 53 Hannu's code. Please bear that in mind when considering the appropriate 54 forums for bug reporting. 55 56The modular sound drivers may be loaded via insmod or modprobe. 57To support all the various sound modules, there are two general 58support modules that must be loaded first: 59 60 soundcore.o: Top level handler for the sound system, provides 61 a set of functions for registration of devices 62 by type. 63 64 sound.o: Common sound functions required by all modules. 65 66For the specific sound modules (e.g., sb.o for the Soundblaster), 67read the documentation on that module to determine what options 68are available, for example IRQ, address, DMA. 69 70Warning, the options for different cards sometime use different names 71for the same or a similar feature (dma1= versus dma16=). As a last 72resort, inspect the code (search for module_param). 73 74Notes: 75 761. There is a new OpenSource sound driver called ALSA which is 77 currently under development: http://www.alsa-project.org/ 78 The ALSA drivers support some newer hardware that may not 79 be supported by this sound driver and also provide some 80 additional features. 81 822. The commercial OSS driver may be obtained from the site: 83 http://www/opensound.com. This may be used for cards that 84 are unsupported by the kernel driver, or may be used 85 by other operating systems. 86 873. The enlightenment sound daemon may be used for playing 88 multiple sounds at the same time via a single card, eliminating 89 some of the requirements for multiple sound card systems. For 90 more information, see: http://www.tux.org/~ricdude/EsounD.html 91 The "esd" program may be used with the real-player and mpeg 92 players like mpg123 and x11amp. The newer real-player 93 and some games even include built-in support for ESD! 94 95 96Building the Modules: 97===================== 98 99This document does not provide full details on building the 100kernel, etc. The notes below apply only to making the kernel 101sound modules. If this conflicts with the kernel's README, 102the README takes precedence. 103 1041. To make the kernel sound modules, cd to your /usr/src/linux 105 directory (typically) and type make config, make menuconfig, 106 or make xconfig (to start the command line, dialog, or x-based 107 configuration tool). 108 1092. Select the Sound option and a dialog will be displayed. 110 1113. Select M (module) for "Sound card support". 112 1134. Select your sound driver(s) as a module. For ProAudio, Sound 114 Blaster, etc., select M (module) for OSS sound modules. 115 [thanks to Marvin Stodolsky <stodolsk@erols.com>]A 116 1175. Make the kernel (e.g., make bzImage), and install the kernel. 118 1196. Make the modules and install them (make modules; make modules_install). 120 121Note, for 2.5.x kernels, make sure you have the newer module-init-tools 122installed or modules will not be loaded properly. 2.5.x requires an 123updated module-init-tools. 124 125 126Plug and Play (PnP: 127=================== 128 129If the sound card is an ISA PnP card, isapnp may be used 130to configure the card. See the file isapnp.txt in the 131directory one level up (e.g., /usr/src/linux/Documentation). 132 133Also the 2.4.x kernels provide PnP capabilities, see the 134file NEWS in this directory. 135 136PCI sound cards are highly recommended, as they are far 137easier to configure and from what I have read, they use 138less resources and are more CPU efficient. 139 140 141INSMOD: 142======= 143 144If loading via insmod, the common modules must be loaded in the 145order below BEFORE loading the other sound modules. The card-specific 146modules may then be loaded (most require parameters). For example, 147I use the following via a shell script to load my SoundBlaster: 148 149SB_BASE=0x240 150SB_IRQ=9 151SB_DMA=3 152SB_DMA2=5 153SB_MPU=0x300 154# 155echo Starting sound 156/sbin/insmod soundcore 157/sbin/insmod sound 158# 159echo Starting sound blaster.... 160/sbin/insmod uart401 161/sbin/insmod sb io=$SB_BASE irq=$SB_IRQ dma=$SB_DMA dma16=$SB_DMA2 mpu_io=$SB_MP 162 163When using sound as a module, I typically put these commands 164in a file such as /root/soundon.sh. 165 166 167MODPROBE: 168========= 169 170If loading via modprobe, these common files are automatically loaded 171when requested by modprobe. For example, my /etc/modprobe.conf contains: 172 173alias sound sb 174options sb io=0x240 irq=9 dma=3 dma16=5 mpu_io=0x300 175 176All you need to do to load the module is: 177 178 /sbin/modprobe sb 179 180 181Sound Status: 182============= 183 184The status of sound may be read/checked by: 185 cat (anyfile).au >/dev/audio 186 187[WWH: This may not work properly for SoundBlaster PCI 128 cards 188such as the es1370/1 (see the es1370/1 files in this directory) 189as they do not automatically support uLaw on /dev/audio.] 190 191The status of the modules and which modules depend on 192which other modules may be checked by: 193 /sbin/lsmod 194 195/sbin/lsmod should show something like the following: 196 sb 26280 0 197 uart401 5640 0 [sb] 198 sound 57112 0 [sb uart401] 199 soundcore 1968 8 [sb sound] 200 201 202Removing Sound: 203=============== 204 205Sound may be removed by using /sbin/rmmod in the reverse order 206in which you load the modules. Note, if a program has a sound device 207open (e.g., xmixer), that module (and the modules on which it 208depends) may not be unloaded. 209 210For example, I use the following to remove my Soundblaster (rmmod 211in the reverse order in which I loaded the modules): 212 213/sbin/rmmod sb 214/sbin/rmmod uart401 215/sbin/rmmod sound 216/sbin/rmmod soundcore 217 218When using sound as a module, I typically put these commands 219in a script such as /root/soundoff.sh. 220 221 222Removing Sound for use with OSS: 223================================ 224 225If you get really stuck or have a card that the kernel modules 226will not support, you can get a commercial sound driver from 227http://www.opensound.com. Before loading the commercial sound 228driver, you should do the following: 229 2301. remove sound modules (detailed above) 2312. remove the sound modules from /etc/modprobe.conf 2323. move the sound modules from /lib/modules/<kernel>/misc 233 (for example, I make a /lib/modules/<kernel>/misc/tmp 234 directory and copy the sound module files to that 235 directory). 236 237 238Multiple Sound Cards: 239===================== 240 241The sound drivers will support multiple sound cards and there 242are some great applications like multitrack that support them. 243Typically, you need two sound cards of different types. Note, this 244uses more precious interrupts and DMA channels and sometimes 245can be a configuration nightmare. I have heard reports of 3-4 246sound cards (typically I only use 2). You can sometimes use 247multiple PCI sound cards of the same type. 248 249On my machine I have two sound cards (cs4232 and Soundblaster Vibra 25016). By loading sound as modules, I can control which is the first 251sound device (/dev/dsp, /dev/audio, /dev/mixer) and which is 252the second. Normally, the cs4232 (Dell sound on the motherboard) 253would be the first sound device, but I prefer the Soundblaster. 254All you have to do is to load the one you want as /dev/dsp 255first (in my case "sb") and then load the other one 256(in my case "cs4232"). 257 258If you have two cards of the same type that are jumpered 259cards or different PnP revisions, you may load the same 260module twice. For example, I have a SoundBlaster vibra 16 261and an older SoundBlaster 16 (jumpers). To load the module 262twice, you need to do the following: 263 2641. Copy the sound modules to a new name. For example 265 sb.o could be copied (or symlinked) to sb1.o for the 266 second SoundBlaster. 267 2682. Make a second entry in /etc/modprobe.conf, for example, 269 sound1 or sb1. This second entry should refer to the 270 new module names for example sb1, and should include 271 the I/O, etc. for the second sound card. 272 2733. Update your soundon.sh script, etc. 274 275Warning: I have never been able to get two PnP sound cards of the 276same type to load at the same time. I have tried this several times 277with the Soundblaster Vibra 16 cards. OSS has indicated that this 278is a PnP problem.... If anyone has any luck doing this, please 279send me an E-MAIL. PCI sound cards should not have this problem.a 280Since this was originally release, I have received a couple of 281mails from people who have accomplished this! 282 283NOTE: In Linux 2.4 the Sound Blaster driver (and only this one yet) 284supports multiple cards with one module by default. 285Read the file 'Soundblaster' in this directory for details. 286 287 288Sound Problems: 289=============== 290 291First RTFM (including the troubleshooting section 292in the Sound-HOWTO). 293 2941) If you are having problems loading the modules (for 295 example, if you get device conflict errors) try the 296 following: 297 298 A) If you have Win95 or NT on the same computer, 299 write down what addresses, IRQ, and DMA channels 300 those were using for the same hardware. You probably 301 can use these addresses, IRQs, and DMA channels. 302 You should really do this BEFORE attempting to get 303 sound working! 304 305 B) Check (cat) /proc/interrupts, /proc/ioports, 306 and /proc/dma. Are you trying to use an address, 307 IRQ or DMA port that another device is using? 308 309 C) Check (cat) /proc/isapnp 310 311 D) Inspect your /var/log/messages file. Often that will 312 indicate what IRQ or IO port could not be obtained. 313 314 E) Try another port or IRQ. Note this may involve 315 using the PnP tools to move the sound card to 316 another location. Sometimes this is the only way 317 and it is more or less trial and error. 318 3192) If you get motor-boating (the same sound or part of a 320 sound clip repeated), you probably have either an IRQ 321 or DMA conflict. Move the card to another IRQ or DMA 322 port. This has happened to me when playing long files 323 when I had an IRQ conflict. 324 3253. If you get dropouts or pauses when playing high sample 326 rate files such as using mpg123 or x11amp/xmms, you may 327 have too slow of a CPU and may have to use the options to 328 play the files at 1/2 speed. For example, you may use 329 the -2 or -4 option on mpg123. You may also get this 330 when trying to play mpeg files stored on a CD-ROM 331 (my Toshiba T8000 PII/366 sometimes has this problem). 332 3334. If you get "cannot access device" errors, your /dev/dsp 334 files, etc. may be set to owner root, mode 600. You 335 may have to use the command: 336 chmod 666 /dev/dsp /dev/mixer /dev/audio 337 3385. If you get "device busy" errors, another program has the 339 sound device open. For example, if using the Enlightenment 340 sound daemon "esd", the "esd" program has the sound device. 341 If using "esd", please RTFM the docs on ESD. For example, 342 esddsp <program> may be used to play files via a non-esd 343 aware program. 344 3456) Ask for help on the sound list or send E-MAIL to the 346 sound driver author/maintainer. 347 3487) Turn on debug in drivers/sound/sound_config.h (DEB, DDB, MDB). 349 3508) If the system reports insufficient DMA memory then you may want to 351 load sound with the "dmabufs=1" option. Or in /etc/conf.modules add 352 353 preinstall sound dmabufs=1 354 355 This makes the sound system allocate its buffers and hang onto them. 356 357 You may also set persistent DMA when building a 2.4.x kernel. 358 359 360Configuring Sound: 361================== 362 363There are several ways of configuring your sound: 364 3651) On the kernel command line (when using the sound driver(s) 366 compiled in the kernel). Check the driver source and 367 documentation for details. 368 3692) On the command line when using insmod or in a bash script 370 using command line calls to load sound. 371 3723) In /etc/modprobe.conf when using modprobe. 373 3744) Via Red Hat's GPL'd /usr/sbin/sndconfig program (text based). 375 3765) Via the OSS soundconf program (with the commercial version 377 of the OSS driver. 378 3796) By just loading the module and let isapnp do everything relevant 380 for you. This works only with a few drivers yet and - of course - 381 only with isapnp hardware. 382 383And I am sure, several other ways. 384 385Anyone want to write a linuxconf module for configuring sound? 386 387 388Module Loading: 389=============== 390 391When a sound card is first referenced and sound is modular, the sound system 392will ask for the sound devices to be loaded. Initially it requests that 393the driver for the sound system is loaded. It then will ask for 394sound-slot-0, where 0 is the first sound card. (sound-slot-1 the second and 395so on). Thus you can do 396 397alias sound-slot-0 sb 398 399To load a soundblaster at this point. If the slot loading does not provide 400the desired device - for example a soundblaster does not directly provide 401a midi synth in all cases then it will request "sound-service-0-n" where n 402is 403 404 0 Mixer 405 406 2 MIDI 407 408 3, 4 DSP audio 409 410 411For example, I use the following to load my Soundblaster PCI 128 412(ES 1371) card first, followed by my SoundBlaster Vibra 16 card, 413then by my TV card: 414 415# Load the Soundblaster PCI 128 as /dev/dsp, /dev/dsp1, /dev/mixer 416alias sound-slot-0 es1371 417 418# Load the Soundblaster Vibra 16 as /dev/dsp2, /dev/mixer1 419alias sound-slot-1 sb 420options sb io=0x240 irq=5 dma=1 dma16=5 mpu_io=0x330 421 422# Load the BTTV (TV card) as /dev/mixer2 423alias sound-slot-2 bttv 424alias sound-service-2-0 tvmixer 425 426pre-install bttv modprobe tuner ; modprobe tvmixer 427pre-install tvmixer modprobe msp3400; modprobe tvaudio 428options tuner debug=0 type=8 429options bttv card=0 radio=0 pll=0 430 431 432For More Information (RTFM): 433============================ 4341) Information on kernel modules: manual pages for insmod and modprobe. 435 4362) Information on PnP, RTFM manual pages for isapnp. 437 4383) Sound-HOWTO and Sound-Playing-HOWTO. 439 4404) OSS's WWW site at http://www.opensound.com. 441 4425) All the files in Documentation/sound. 443 4446) The comments and code in linux/drivers/sound. 445 4467) The sndconfig and rhsound documentation from Red Hat. 447 4488) The Linux-sound mailing list: sound-list@redhat.com. 449 4509) Enlightenment documentation (for info on esd) 451 http://www.tux.org/~ricdude/EsounD.html. 452 45310) ALSA home page: http://www.alsa-project.org/ 454 455 456Contact Information: 457==================== 458Wade Hampton: (whampton@staffnet.com) 459