1 MORE NOTES ON HD-AUDIO DRIVER
2 =============================
3 Takashi Iwai <tiwai@suse.de>
9 HD-audio is the new standard on-board audio component on modern PCs
10 after AC97. Although Linux has been supporting HD-audio since long
11 time ago, there are often problems with new machines. A part of the
12 problem is broken BIOS, and the rest is the driver implementation.
13 This document explains the brief trouble-shooting and debugging
14 methods for the HD-audio hardware.
16 The HD-audio component consists of two parts: the controller chip and
17 the codec chips on the HD-audio bus. Linux provides a single driver
18 for all controllers, snd-hda-intel. Although the driver name contains
19 a word of a well-known hardware vendor, it's not specific to it but for
20 all controller chips by other companies. Since the HD-audio
21 controllers are supposed to be compatible, the single snd-hda-driver
22 should work in most cases. But, not surprisingly, there are known
23 bugs and issues specific to each controller type. The snd-hda-intel
24 driver has a bunch of workarounds for these as described below.
26 A controller may have multiple codecs. Usually you have one audio
27 codec and optionally one modem codec. In theory, there might be
28 multiple audio codecs, e.g. for analog and digital outputs, and the
29 driver might not work properly because of conflict of mixer elements.
30 This should be fixed in future if such hardware really exists.
32 The snd-hda-intel driver has several different codec parsers depending
33 on the codec. It has a generic parser as a fallback, but this
34 functionality is fairly limited until now. Instead of the generic
35 parser, usually the codec-specific parser (coded in patch_*.c) is used
36 for the codec-specific implementations. The details about the
37 codec-specific problems are explained in the later sections.
39 If you are interested in the deep debugging of HD-audio, read the
40 HD-audio specification at first. The specification is found on
41 Intel's web page, for example:
43 - http://www.intel.com/standards/hdaudio/
51 The most common problem of the controller is the inaccurate DMA
52 pointer reporting. The DMA pointer for playback and capture can be
53 read in two ways, either via a LPIB register or via a position-buffer
54 map. As default the driver tries to read from the io-mapped
55 position-buffer, and falls back to LPIB if the position-buffer appears
56 dead. However, this detection isn't perfect on some devices. In such
57 a case, you can change the default method via `position_fix` option.
59 `position_fix=1` means to use LPIB method explicitly.
60 `position_fix=2` means to use the position-buffer. 0 is the default
61 value, the automatic check and fallback to LPIB as described in the
62 above. If you get a problem of repeated sounds, this option might
65 In addition to that, every controller is known to be broken regarding
66 the wake-up timing. It wakes up a few samples before actually
67 processing the data on the buffer. This caused a lot of problems, for
68 example, with ALSA dmix or JACK. Since 2.6.27 kernel, the driver puts
69 an artificial delay to the wake up timing. This delay is controlled
70 via `bdl_pos_adj` option.
72 When `bdl_pos_adj` is a negative value (as default), it's assigned to
73 an appropriate value depending on the controller chip. For Intel
74 chips, it'd be 1 while it'd be 32 for others. Usually this works.
75 Only in case it doesn't work and you get warning messages, you should
76 change this parameter to other values.
81 A less often but a more severe problem is the codec probing. When
82 BIOS reports the available codec slots wrongly, the driver gets
83 confused and tries to access the non-existing codec slot. This often
84 results in the total screw-up, and destructs the further communication
85 with the codec chips. The symptom appears usually as error messages
87 ------------------------------------------------------------------------
88 hda_intel: azx_get_response timeout, switching to polling mode:
90 hda_intel: azx_get_response timeout, switching to single_cmd mode:
92 ------------------------------------------------------------------------
94 The first line is a warning, and this is usually relatively harmless.
95 It means that the codec response isn't notified via an IRQ. The
96 driver uses explicit polling method to read the response. It gives
97 very slight CPU overhead, but you'd unlikely notice it.
99 The second line is, however, a fatal error. If this happens, usually
100 it means that something is really wrong. Most likely you are
101 accessing a non-existing codec slot.
103 Thus, if the second error message appears, try to narrow the probed
104 codec slots via `probe_mask` option. It's a bitmask, and each bit
105 corresponds to the codec slot. For example, to probe only the first
106 slot, pass `probe_mask=1`. For the first and the third slots, pass
107 `probe_mask=5` (where 5 = 1 | 4), and so on.
109 Since 2.6.29 kernel, the driver has a more robust probing method, so
110 this error might happen rarely, though.
112 On a machine with a broken BIOS, sometimes you need to force the
113 driver to probe the codec slots the hardware doesn't report for use.
114 In such a case, turn the bit 8 (0x100) of `probe_mask` option on.
115 Then the rest 8 bits are passed as the codec slots to probe
116 unconditionally. For example, `probe_mask=0x103` will force to probe
117 the codec slots 0 and 1 no matter what the hardware reports.
122 In rare but some cases, the interrupt isn't properly handled as
123 default. You would notice this by the DMA transfer error reported by
124 ALSA PCM core, for example. Using MSI might help in such a case.
125 Pass `enable_msi=1` option for enabling MSI.
133 The most common problem regarding the HD-audio driver is the
134 unsupported codec features or the mismatched device configuration.
135 Most of codec-specific code has several preset models, either to
136 override the BIOS setup or to provide more comprehensive features.
138 The driver checks PCI SSID and looks through the static configuration
139 table until any matching entry is found. If you have a new machine,
140 you may see a message like below:
141 ------------------------------------------------------------------------
142 hda_codec: ALC880: BIOS auto-probing.
143 ------------------------------------------------------------------------
144 Meanwhile, in the earlier versions, you would see a message like:
145 ------------------------------------------------------------------------
146 hda_codec: Unknown model for ALC880, trying auto-probe from BIOS...
147 ------------------------------------------------------------------------
148 Even if you see such a message, DON'T PANIC. Take a deep breath and
149 keep your towel. First of all, it's an informational message, no
150 warning, no error. This means that the PCI SSID of your device isn't
151 listed in the known preset model (white-)list. But, this doesn't mean
152 that the driver is broken. Many codec-drivers provide the automatic
153 configuration mechanism based on the BIOS setup.
155 The HD-audio codec has usually "pin" widgets, and BIOS sets the default
156 configuration of each pin, which indicates the location, the
157 connection type, the jack color, etc. The HD-audio driver can guess
158 the right connection judging from these default configuration values.
159 However -- some codec-support codes, such as patch_analog.c, don't
160 support the automatic probing (yet as of 2.6.28). And, BIOS is often,
161 yes, pretty often broken. It sets up wrong values and screws up the
164 The preset model is provided basically to overcome such a situation.
165 When the matching preset model is found in the white-list, the driver
166 assumes the static configuration of that preset and builds the mixer
167 elements and PCM streams based on the static information. Thus, if
168 you have a newer machine with a slightly different PCI SSID from the
169 existing one, you may have a good chance to re-use the same model.
170 You can pass the `model` option to specify the preset model instead of
173 What `model` option values are available depends on the codec chip.
174 Check your codec chip from the codec proc file (see "Codec Proc-File"
175 section below). It will show the vendor/product name of your codec
176 chip. Then, see Documentation/sound/alsa/HD-Audio-Models.txt file,
177 the section of HD-audio driver. You can find a list of codecs
178 and `model` options belonging to each codec. For example, for Realtek
179 ALC262 codec chip, pass `model=ultra` for devices that are compatible
180 with Samsung Q1 Ultra.
182 Thus, the first thing you can do for any brand-new, unsupported and
183 non-working HD-audio hardware is to check HD-audio codec and several
184 different `model` option values. If you have any luck, some of them
185 might suit with your device well.
187 Some codecs such as ALC880 have a special model option `model=test`.
188 This configures the driver to provide as many mixer controls as
189 possible for every single pin feature except for the unsolicited
190 events (and maybe some other specials). Adjust each mixer element and
191 try the I/O in the way of trial-and-error until figuring out the whole
194 Note that `model=generic` has a special meaning. It means to use the
195 generic parser regardless of the codec. Usually the codec-specific
196 parser is much better than the generic parser (as now). Thus this
197 option is more about the debugging purpose.
200 Speaker and Headphone Output
201 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
202 One of the most frequent (and obvious) bugs with HD-audio is the
203 silent output from either or both of a built-in speaker and a
204 headphone jack. In general, you should try a headphone output at
205 first. A speaker output often requires more additional controls like
206 the external amplifier bits. Thus a headphone output has a slightly
209 Before making a bug report, double-check whether the mixer is set up
210 correctly. The recent version of snd-hda-intel driver provides mostly
211 "Master" volume control as well as "Front" volume (where Front
212 indicates the front-channels). In addition, there can be individual
213 "Headphone" and "Speaker" controls.
215 Ditto for the speaker output. There can be "External Amplifier"
216 switch on some codecs. Turn on this if present.
218 Another related problem is the automatic mute of speaker output by
219 headphone plugging. This feature is implemented in most cases, but
220 not on every preset model or codec-support code.
222 In anyway, try a different model option if you have such a problem.
223 Some other models may match better and give you more matching
224 functionality. If none of the available models works, send a bug
225 report. See the bug report section for details.
227 If you are masochistic enough to debug the driver problem, note the
230 - The speaker (and the headphone, too) output often requires the
231 external amplifier. This can be set usually via EAPD verb or a
232 certain GPIO. If the codec pin supports EAPD, you have a better
233 chance via SET_EAPD_BTL verb (0x70c). On others, GPIO pin (mostly
234 it's either GPIO0 or GPIO1) may turn on/off EAPD.
235 - Some Realtek codecs require special vendor-specific coefficients to
236 turn on the amplifier. See patch_realtek.c.
237 - IDT codecs may have extra power-enable/disable controls on each
238 analog pin. See patch_sigmatel.c.
239 - Very rare but some devices don't accept the pin-detection verb until
240 triggered. Issuing GET_PIN_SENSE verb (0xf09) may result in the
241 codec-communication stall. Some examples are found in
247 The capture problems are often because of missing setups of mixers.
248 Thus, before submitting a bug report, make sure that you set up the
249 mixer correctly. For example, both "Capture Volume" and "Capture
250 Switch" have to be set properly in addition to the right "Capture
251 Source" or "Input Source" selection. Some devices have "Mic Boost"
254 When the PCM device is opened via "default" PCM (without pulse-audio
255 plugin), you'll likely have "Digital Capture Volume" control as well.
256 This is provided for the extra gain/attenuation of the signal in
257 software, especially for the inputs without the hardware volume
258 control such as digital microphones. Unless really needed, this
259 should be set to exactly 50%, corresponding to 0dB -- neither extra
260 gain nor attenuation. When you use "hw" PCM, i.e., a raw access PCM,
261 this control will have no influence, though.
263 It's known that some codecs / devices have fairly bad analog circuits,
264 and the recorded sound contains a certain DC-offset. This is no bug
267 Most of modern laptops have no analog CD-input connection. Thus, the
268 recording from CD input won't work in many cases although the driver
269 provides it as the capture source. Use CDDA instead.
271 The automatic switching of the built-in and external mic per plugging
272 is implemented on some codec models but not on every model. Partly
273 because of my laziness but mostly lack of testers. Feel free to
274 submit the improvement patch to the author.
279 If no model option gives you a better result, and you are a tough guy
280 to fight against evil, try debugging via hitting the raw HD-audio
281 codec verbs to the device. Some tools are available: hda-emu and
282 hda-analyzer. The detailed description is found in the sections
283 below. You'd need to enable hwdep for using these tools. See "Kernel
284 Configuration" section.
292 In general, I recommend you to enable the sound debug option,
293 `CONFIG_SND_DEBUG=y`, no matter whether you are debugging or not.
294 This enables snd_printd() macro and others, and you'll get additional
295 kernel messages at probing.
297 In addition, you can enable `CONFIG_SND_DEBUG_VERBOSE=y`. But this
298 will give you far more messages. Thus turn this on only when you are
301 Don't forget to turn on the appropriate `CONFIG_SND_HDA_CODEC_*`
302 options. Note that each of them corresponds to the codec chip, not
303 the controller chip. Thus, even if lspci shows the Nvidia controller,
304 you may need to choose the option for other vendors. If you are
305 unsure, just select all yes.
307 `CONFIG_SND_HDA_HWDEP` is a useful option for debugging the driver.
308 When this is enabled, the driver creates hardware-dependent devices
309 (one per each codec), and you have a raw access to the device via
310 these device files. For example, `hwC0D2` will be created for the
311 codec slot #2 of the first card (#0). For debug-tools such as
312 hda-verb and hda-analyzer, the hwdep device has to be enabled.
313 Thus, it'd be better to turn this on always.
315 `CONFIG_SND_HDA_RECONFIG` is a new option, and this depends on the
316 hwdep option above. When enabled, you'll have some sysfs files under
317 the corresponding hwdep directory. See "HD-audio reconfiguration"
320 `CONFIG_SND_HDA_POWER_SAVE` option enables the power-saving feature.
321 See "Power-saving" section below.
326 The codec proc-file is a treasure-chest for debugging HD-audio.
327 It shows most of useful information of each codec widget.
329 The proc file is located in /proc/asound/card*/codec#*, one file per
330 each codec slot. You can know the codec vendor, product id and
331 names, the type of each widget, capabilities and so on.
332 This file, however, doesn't show the jack sensing state, so far. This
333 is because the jack-sensing might be depending on the trigger state.
335 This file will be picked up by the debug tools, and also it can be fed
336 to the emulator as the primary codec information. See the debug tools
339 This proc file can be also used to check whether the generic parser is
340 used. When the generic parser is used, the vendor/product ID name
341 will appear as "Realtek ID 0262", instead of "Realtek ALC262".
344 HD-Audio Reconfiguration
345 ~~~~~~~~~~~~~~~~~~~~~~~~
346 This is an experimental feature to allow you re-configure the HD-audio
347 codec dynamically without reloading the driver. The following sysfs
348 files are available under each codec-hwdep device directory (e.g.
349 /sys/class/sound/hwC0D0):
352 Shows the 32bit codec vendor-id hex number. You can change the
353 vendor-id value by writing to this file.
355 Shows the 32bit codec subsystem-id hex number. You can change the
356 subsystem-id value by writing to this file.
358 Shows the 32bit codec revision-id hex number. You can change the
359 revision-id value by writing to this file.
361 Shows the AFG ID. This is read-only.
363 Shows the MFG ID. This is read-only.
365 Shows the codec name string. Can be changed by writing to this
368 Shows the currently set `model` option. Can be changed by writing
371 The extra verbs to execute at initialization. You can add a verb by
372 writing to this file. Pass three numbers: nid, verb and parameter
373 (separated with a space).
375 Shows / stores hint strings for codec parsers for any use.
376 Its format is `key = value`. For example, passing `hp_detect = yes`
377 to IDT/STAC codec parser will result in the disablement of the
380 Shows the initial pin default config values set by BIOS.
382 Shows the pin default values set by the codec parser explicitly.
383 This doesn't show all pin values but only the changed values by
384 the parser. That is, if the parser doesn't change the pin default
385 config values by itself, this will contain nothing.
387 Shows the pin default config values to override the BIOS setup.
388 Writing this (with two numbers, NID and value) appends the new
389 value. The given will be used instead of the initial BIOS value at
390 the next reconfiguration time. Note that this config will override
391 even the driver pin configs, too.
393 Triggers the codec re-configuration. When any value is written to
394 this file, the driver re-initialize and parses the codec tree
395 again. All the changes done by the sysfs entries above are taken
398 Resets the codec, removes the mixer elements and PCM stuff of the
399 specified codec, and clear all init verbs and hints.
401 For example, when you want to change the pin default configuration
402 value of the pin widget 0x14 to 0x9993013f, and let the driver
403 re-configure based on that state, run like below:
404 ------------------------------------------------------------------------
405 # echo 0x14 0x9993013f > /sys/class/sound/hwC0D0/user_pin_configs
406 # echo 1 > /sys/class/sound/hwC0D0/reconfig
407 ------------------------------------------------------------------------
412 When CONFIG_SND_HDA_PATCH_LOADER=y is set, you can pass a "patch" as a
413 firmware file for modifying the HD-audio setup before initializing the
414 codec. This can work basically like the reconfiguration via sysfs in
415 the above, but it does it before the first codec configuration.
417 A patch file is a plain text file which looks like below:
419 ------------------------------------------------------------------------
421 0x12345678 0xabcd1234 2
435 ------------------------------------------------------------------------
437 The file needs to have a line `[codec]`. The next line should contain
438 three numbers indicating the codec vendor-id (0x12345678 in the
439 example), the codec subsystem-id (0xabcd1234) and the address (2) of
440 the codec. The rest patch entries are applied to this specified codec
441 until another codec entry is given.
443 The `[model]` line allows to change the model name of the each codec.
444 In the example above, it will be changed to model=auto.
445 Note that this overrides the module option.
447 After the `[pincfg]` line, the contents are parsed as the initial
448 default pin-configurations just like `user_pin_configs` sysfs above.
449 The values can be shown in user_pin_configs sysfs file, too.
451 Similarly, the lines after `[verb]` are parsed as `init_verbs`
452 sysfs entries, and the lines after `[hint]` are parsed as `hints`
453 sysfs entries, respectively.
455 Another example to override the codec vendor id from 0x12345678 to
456 0xdeadbeef is like below:
457 ------------------------------------------------------------------------
459 0x12345678 0xabcd1234 2
463 ------------------------------------------------------------------------
465 In the similar way, you can override the codec subsystem_id via
466 `[subsystem_id]`, the revision id via `[revision_id]` line.
467 Also, the codec chip name can be rewritten via `[chip_name]` line.
468 ------------------------------------------------------------------------
470 0x12345678 0xabcd1234 2
480 ------------------------------------------------------------------------
482 The hd-audio driver reads the file via request_firmware(). Thus,
483 a patch file has to be located on the appropriate firmware path,
484 typically, /lib/firmware. For example, when you pass the option
485 `patch=hda-init.fw`, the file /lib/firmware/hda-init-fw must be
488 The patch module option is specific to each card instance, and you
489 need to give one file name for each instance, separated by commas.
490 For example, if you have two cards, one for an on-board analog and one
491 for an HDMI video board, you may pass patch option like below:
492 ------------------------------------------------------------------------
493 options snd-hda-intel patch=on-board-patch,hdmi-patch
494 ------------------------------------------------------------------------
499 The power-saving is a kind of auto-suspend of the device. When the
500 device is inactive for a certain time, the device is automatically
501 turned off to save the power. The time to go down is specified via
502 `power_save` module option, and this option can be changed dynamically
505 The power-saving won't work when the analog loopback is enabled on
506 some codecs. Make sure that you mute all unneeded signal routes when
507 you want the power-saving.
509 The power-saving feature might cause audible click noises at each
510 power-down/up depending on the device. Some of them might be
511 solvable, but some are hard, I'm afraid. Some distros such as
512 openSUSE enables the power-saving feature automatically when the power
513 cable is unplugged. Thus, if you hear noises, suspect first the
514 power-saving. See /sys/module/snd_hda_intel/parameters/power_save to
515 check the current value. If it's non-zero, the feature is turned on.
520 The latest development codes for HD-audio are found on sound git tree:
522 - git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6.git
524 The master branch or for-next branches can be used as the main
525 development branches in general while the HD-audio specific patches
526 are committed in topic/hda branch.
528 If you are using the latest Linus tree, it'd be better to pull the
529 above GIT tree onto it. If you are using the older kernels, an easy
530 way to try the latest ALSA code is to build from the snapshot
531 tarball. There are daily tarballs and the latest snapshot tarball.
532 All can be built just like normal alsa-driver release packages, that
533 is, installed via the usual spells: configure, make and make
534 install(-modules). See INSTALL in the package. The snapshot tarballs
537 - ftp://ftp.kernel.org/pub/linux/kernel/people/tiwai/snapshot/
542 If any model or module options don't work for your device, it's time
543 to send a bug report to the developers. Give the following in your
546 - Hardware vendor, product and model names
547 - Kernel version (and ALSA-driver version if you built externally)
548 - `alsa-info.sh` output; run with `--no-upload` option. See the
549 section below about alsa-info
551 If it's a regression, at best, send alsa-info outputs of both working
552 and non-working kernels. This is really helpful because we can
553 compare the codec registers directly.
555 Send a bug report either the followings:
558 http://bugme.linux-foundation.org/
560 alsa-devel@alsa-project.org
566 This section describes some tools available for debugging HD-audio
571 The script `alsa-info.sh` is a very useful tool to gather the audio
572 device information. You can fetch the latest version from:
574 - http://www.alsa-project.org/alsa-info.sh
576 Run this script as root, and it will gather the important information
577 such as the module lists, module parameters, proc file contents
578 including the codec proc files, mixer outputs and the control
579 elements. As default, it will store the information onto a web server
580 on alsa-project.org. But, if you send a bug report, it'd be better to
581 run with `--no-upload` option, and attach the generated file.
583 There are some other useful options. See `--help` option output for
586 When a probe error occurs or when the driver obviously assigns a
587 mismatched model, it'd be helpful to load the driver with
588 `probe_only=1` option (at best after the cold reboot) and run
589 alsa-info at this state. With this option, the driver won't configure
590 the mixer and PCM but just tries to probe the codec slot. After
591 probing, the proc file is available, so you can get the raw codec
592 information before modified by the driver. Of course, the driver
593 isn't usable with `probe_only=1`. But you can continue the
594 configuration via hwdep sysfs file if hda-reconfig option is enabled.
599 hda-verb is a tiny program that allows you to access the HD-audio
600 codec directly. You can execute a raw HD-audio codec verb with this.
601 This program accesses the hwdep device, thus you need to enable the
602 kernel config `CONFIG_SND_HDA_HWDEP=y` beforehand.
604 The hda-verb program takes four arguments: the hwdep device file, the
605 widget NID, the verb and the parameter. When you access to the codec
606 on the slot 2 of the card 0, pass /dev/snd/hwC0D2 to the first
607 argument, typically. (However, the real path name depends on the
610 The second parameter is the widget number-id to access. The third
611 parameter can be either a hex/digit number or a string corresponding
612 to a verb. Similarly, the last parameter is the value to write, or
613 can be a string for the parameter type.
615 ------------------------------------------------------------------------
616 % hda-verb /dev/snd/hwC0D0 0x12 0x701 2
617 nid = 0x12, verb = 0x701, param = 0x2
620 % hda-verb /dev/snd/hwC0D0 0x0 PARAMETERS VENDOR_ID
621 nid = 0x0, verb = 0xf00, param = 0x0
624 % hda-verb /dev/snd/hwC0D0 2 set_a 0xb080
625 nid = 0x2, verb = 0x300, param = 0xb080
627 ------------------------------------------------------------------------
629 Although you can issue any verbs with this program, the driver state
630 won't be always updated. For example, the volume values are usually
631 cached in the driver, and thus changing the widget amp value directly
632 via hda-verb won't change the mixer value.
634 The hda-verb program is found in the ftp directory:
636 - ftp://ftp.kernel.org/pub/linux/kernel/people/tiwai/misc/
638 Also a git repository is available:
640 - git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/hda-verb.git
642 See README file in the tarball for more details about hda-verb
648 hda-analyzer provides a graphical interface to access the raw HD-audio
649 control, based on pyGTK2 binding. It's a more powerful version of
650 hda-verb. The program gives you an easy-to-use GUI stuff for showing
651 the widget information and adjusting the amp values, as well as the
652 proc-compatible output.
656 - http://git.alsa-project.org/?p=alsa.git;a=tree;f=hda-analyzer
658 is a part of alsa.git repository in alsa-project.org:
660 - git://git.alsa-project.org/alsa.git
664 Codecgraph is a utility program to generate a graph and visualizes the
665 codec-node connection of a codec chip. It's especially useful when
666 you analyze or debug a codec without a proper datasheet. The program
667 parses the given codec proc file and converts to SVG via graphiz
670 The tarball and GIT trees are found in the web page at:
672 - http://helllabs.org/codecgraph/
677 hda-emu is an HD-audio emulator. The main purpose of this program is
678 to debug an HD-audio codec without the real hardware. Thus, it
679 doesn't emulate the behavior with the real audio I/O, but it just
680 dumps the codec register changes and the ALSA-driver internal changes
681 at probing and operating the HD-audio driver.
683 The program requires a codec proc-file to simulate. Get a proc file
684 for the target codec beforehand, or pick up an example codec from the
685 codec proc collections in the tarball. Then, run the program with the
686 proc file, and the hda-emu program will start parsing the codec file
687 and simulates the HD-audio driver:
689 ------------------------------------------------------------------------
690 % hda-emu codecs/stac9200-dell-d820-laptop
692 hda_codec: Unknown model for STAC9200, using BIOS defaults
693 hda_codec: pin nid 08 bios pin config 40c003fa
695 ------------------------------------------------------------------------
697 The program gives you only a very dumb command-line interface. You
698 can get a proc-file dump at the current state, get a list of control
699 (mixer) elements, set/get the control element value, simulate the PCM
700 operation, the jack plugging simulation, etc.
702 The package is found in:
704 - ftp://ftp.kernel.org/pub/linux/kernel/people/tiwai/misc/
706 A git repository is available:
708 - git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/hda-emu.git
710 See README file in the tarball for more details about hda-emu
git.openpandora.org / pandora-kernel.git / blob