1MORE NOTES ON HD-AUDIO DRIVER 2============================= 3 Takashi Iwai <tiwai@suse.de> 4 5 6GENERAL 7------- 8 9HD-audio is the new standard on-board audio component on modern PCs 10after AC97. Although Linux has been supporting HD-audio since long 11time ago, there are often problems with new machines. A part of the 12problem is broken BIOS, and the rest is the driver implementation. 13This document explains the brief trouble-shooting and debugging 14methods for the HD-audio hardware. 15 16The HD-audio component consists of two parts: the controller chip and 17the codec chips on the HD-audio bus. Linux provides a single driver 18for all controllers, snd-hda-intel. Although the driver name contains 19a word of a well-known hardware vendor, it's not specific to it but for 20all controller chips by other companies. Since the HD-audio 21controllers are supposed to be compatible, the single snd-hda-driver 22should work in most cases. But, not surprisingly, there are known 23bugs and issues specific to each controller type. The snd-hda-intel 24driver has a bunch of workarounds for these as described below. 25 26A controller may have multiple codecs. Usually you have one audio 27codec and optionally one modem codec. In theory, there might be 28multiple audio codecs, e.g. for analog and digital outputs, and the 29driver might not work properly because of conflict of mixer elements. 30This should be fixed in future if such hardware really exists. 31 32The snd-hda-intel driver has several different codec parsers depending 33on the codec. It has a generic parser as a fallback, but this 34functionality is fairly limited until now. Instead of the generic 35parser, usually the codec-specific parser (coded in patch_*.c) is used 36for the codec-specific implementations. The details about the 37codec-specific problems are explained in the later sections. 38 39If you are interested in the deep debugging of HD-audio, read the 40HD-audio specification at first. The specification is found on 41Intel's web page, for example: 42 43- http://www.intel.com/standards/hdaudio/ 44 45 46HD-AUDIO CONTROLLER 47------------------- 48 49DMA-Position Problem 50~~~~~~~~~~~~~~~~~~~~ 51The most common problem of the controller is the inaccurate DMA 52pointer reporting. The DMA pointer for playback and capture can be 53read in two ways, either via a LPIB register or via a position-buffer 54map. As default the driver tries to read from the io-mapped 55position-buffer, and falls back to LPIB if the position-buffer appears 56dead. However, this detection isn't perfect on some devices. In such 57a case, you can change the default method via `position_fix` option. 58 59`position_fix=1` means to use LPIB method explicitly. 60`position_fix=2` means to use the position-buffer. 61`position_fix=3` means to use a combination of both methods, needed 62for some VIA controllers. The capture stream position is corrected 63by comparing both LPIB and position-buffer values. 64`position_fix=4` is another combination available for all controllers, 65and uses LPIB for the playback and the position-buffer for the capture 66streams. 670 is the default value for all other 68controllers, the automatic check and fallback to LPIB as described in 69the above. If you get a problem of repeated sounds, this option might 70help. 71 72In addition to that, every controller is known to be broken regarding 73the wake-up timing. It wakes up a few samples before actually 74processing the data on the buffer. This caused a lot of problems, for 75example, with ALSA dmix or JACK. Since 2.6.27 kernel, the driver puts 76an artificial delay to the wake up timing. This delay is controlled 77via `bdl_pos_adj` option. 78 79When `bdl_pos_adj` is a negative value (as default), it's assigned to 80an appropriate value depending on the controller chip. For Intel 81chips, it'd be 1 while it'd be 32 for others. Usually this works. 82Only in case it doesn't work and you get warning messages, you should 83change this parameter to other values. 84 85 86Codec-Probing Problem 87~~~~~~~~~~~~~~~~~~~~~ 88A less often but a more severe problem is the codec probing. When 89BIOS reports the available codec slots wrongly, the driver gets 90confused and tries to access the non-existing codec slot. This often 91results in the total screw-up, and destructs the further communication 92with the codec chips. The symptom appears usually as error messages 93like: 94------------------------------------------------------------------------ 95 hda_intel: azx_get_response timeout, switching to polling mode: 96 last cmd=0x12345678 97 hda_intel: azx_get_response timeout, switching to single_cmd mode: 98 last cmd=0x12345678 99------------------------------------------------------------------------ 100 101The first line is a warning, and this is usually relatively harmless. 102It means that the codec response isn't notified via an IRQ. The 103driver uses explicit polling method to read the response. It gives 104very slight CPU overhead, but you'd unlikely notice it. 105 106The second line is, however, a fatal error. If this happens, usually 107it means that something is really wrong. Most likely you are 108accessing a non-existing codec slot. 109 110Thus, if the second error message appears, try to narrow the probed 111codec slots via `probe_mask` option. It's a bitmask, and each bit 112corresponds to the codec slot. For example, to probe only the first 113slot, pass `probe_mask=1`. For the first and the third slots, pass 114`probe_mask=5` (where 5 = 1 | 4), and so on. 115 116Since 2.6.29 kernel, the driver has a more robust probing method, so 117this error might happen rarely, though. 118 119On a machine with a broken BIOS, sometimes you need to force the 120driver to probe the codec slots the hardware doesn't report for use. 121In such a case, turn the bit 8 (0x100) of `probe_mask` option on. 122Then the rest 8 bits are passed as the codec slots to probe 123unconditionally. For example, `probe_mask=0x103` will force to probe 124the codec slots 0 and 1 no matter what the hardware reports. 125 126 127Interrupt Handling 128~~~~~~~~~~~~~~~~~~ 129HD-audio driver uses MSI as default (if available) since 2.6.33 130kernel as MSI works better on some machines, and in general, it's 131better for performance. However, Nvidia controllers showed bad 132regressions with MSI (especially in a combination with AMD chipset), 133thus we disabled MSI for them. 134 135There seem also still other devices that don't work with MSI. If you 136see a regression wrt the sound quality (stuttering, etc) or a lock-up 137in the recent kernel, try to pass `enable_msi=0` option to disable 138MSI. If it works, you can add the known bad device to the blacklist 139defined in hda_intel.c. In such a case, please report and give the 140patch back to the upstream developer. 141 142 143HD-AUDIO CODEC 144-------------- 145 146Model Option 147~~~~~~~~~~~~ 148The most common problem regarding the HD-audio driver is the 149unsupported codec features or the mismatched device configuration. 150Most of codec-specific code has several preset models, either to 151override the BIOS setup or to provide more comprehensive features. 152 153The driver checks PCI SSID and looks through the static configuration 154table until any matching entry is found. If you have a new machine, 155you may see a message like below: 156------------------------------------------------------------------------ 157 hda_codec: ALC880: BIOS auto-probing. 158------------------------------------------------------------------------ 159Meanwhile, in the earlier versions, you would see a message like: 160------------------------------------------------------------------------ 161 hda_codec: Unknown model for ALC880, trying auto-probe from BIOS... 162------------------------------------------------------------------------ 163Even if you see such a message, DON'T PANIC. Take a deep breath and 164keep your towel. First of all, it's an informational message, no 165warning, no error. This means that the PCI SSID of your device isn't 166listed in the known preset model (white-)list. But, this doesn't mean 167that the driver is broken. Many codec-drivers provide the automatic 168configuration mechanism based on the BIOS setup. 169 170The HD-audio codec has usually "pin" widgets, and BIOS sets the default 171configuration of each pin, which indicates the location, the 172connection type, the jack color, etc. The HD-audio driver can guess 173the right connection judging from these default configuration values. 174However -- some codec-support codes, such as patch_analog.c, don't 175support the automatic probing (yet as of 2.6.28). And, BIOS is often, 176yes, pretty often broken. It sets up wrong values and screws up the 177driver. 178 179The preset model (or recently called as "fix-up") is provided 180basically to overcome such a situation. When the matching preset 181model is found in the white-list, the driver assumes the static 182configuration of that preset with the correct pin setup, etc. 183Thus, if you have a newer machine with a slightly different PCI SSID 184(or codec SSID) from the existing one, you may have a good chance to 185re-use the same model. You can pass the `model` option to specify the 186preset model instead of PCI (and codec-) SSID look-up. 187 188What `model` option values are available depends on the codec chip. 189Check your codec chip from the codec proc file (see "Codec Proc-File" 190section below). It will show the vendor/product name of your codec 191chip. Then, see Documentation/sound/alsa/HD-Audio-Models.txt file, 192the section of HD-audio driver. You can find a list of codecs 193and `model` options belonging to each codec. For example, for Realtek 194ALC262 codec chip, pass `model=ultra` for devices that are compatible 195with Samsung Q1 Ultra. 196 197Thus, the first thing you can do for any brand-new, unsupported and 198non-working HD-audio hardware is to check HD-audio codec and several 199different `model` option values. If you have any luck, some of them 200might suit with your device well. 201 202There are a few special model option values: 203- when 'nofixup' is passed, the device-specific fixups in the codec 204 parser are skipped. 205- when `generic` is passed, the codec-specific parser is skipped and 206 only the generic parser is used. 207 208 209Speaker and Headphone Output 210~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 211One of the most frequent (and obvious) bugs with HD-audio is the 212silent output from either or both of a built-in speaker and a 213headphone jack. In general, you should try a headphone output at 214first. A speaker output often requires more additional controls like 215the external amplifier bits. Thus a headphone output has a slightly 216better chance. 217 218Before making a bug report, double-check whether the mixer is set up 219correctly. The recent version of snd-hda-intel driver provides mostly 220"Master" volume control as well as "Front" volume (where Front 221indicates the front-channels). In addition, there can be individual 222"Headphone" and "Speaker" controls. 223 224Ditto for the speaker output. There can be "External Amplifier" 225switch on some codecs. Turn on this if present. 226 227Another related problem is the automatic mute of speaker output by 228headphone plugging. This feature is implemented in most cases, but 229not on every preset model or codec-support code. 230 231In anyway, try a different model option if you have such a problem. 232Some other models may match better and give you more matching 233functionality. If none of the available models works, send a bug 234report. See the bug report section for details. 235 236If you are masochistic enough to debug the driver problem, note the 237following: 238 239- The speaker (and the headphone, too) output often requires the 240 external amplifier. This can be set usually via EAPD verb or a 241 certain GPIO. If the codec pin supports EAPD, you have a better 242 chance via SET_EAPD_BTL verb (0x70c). On others, GPIO pin (mostly 243 it's either GPIO0 or GPIO1) may turn on/off EAPD. 244- Some Realtek codecs require special vendor-specific coefficients to 245 turn on the amplifier. See patch_realtek.c. 246- IDT codecs may have extra power-enable/disable controls on each 247 analog pin. See patch_sigmatel.c. 248- Very rare but some devices don't accept the pin-detection verb until 249 triggered. Issuing GET_PIN_SENSE verb (0xf09) may result in the 250 codec-communication stall. Some examples are found in 251 patch_realtek.c. 252 253 254Capture Problems 255~~~~~~~~~~~~~~~~ 256The capture problems are often because of missing setups of mixers. 257Thus, before submitting a bug report, make sure that you set up the 258mixer correctly. For example, both "Capture Volume" and "Capture 259Switch" have to be set properly in addition to the right "Capture 260Source" or "Input Source" selection. Some devices have "Mic Boost" 261volume or switch. 262 263When the PCM device is opened via "default" PCM (without pulse-audio 264plugin), you'll likely have "Digital Capture Volume" control as well. 265This is provided for the extra gain/attenuation of the signal in 266software, especially for the inputs without the hardware volume 267control such as digital microphones. Unless really needed, this 268should be set to exactly 50%, corresponding to 0dB -- neither extra 269gain nor attenuation. When you use "hw" PCM, i.e., a raw access PCM, 270this control will have no influence, though. 271 272It's known that some codecs / devices have fairly bad analog circuits, 273and the recorded sound contains a certain DC-offset. This is no bug 274of the driver. 275 276Most of modern laptops have no analog CD-input connection. Thus, the 277recording from CD input won't work in many cases although the driver 278provides it as the capture source. Use CDDA instead. 279 280The automatic switching of the built-in and external mic per plugging 281is implemented on some codec models but not on every model. Partly 282because of my laziness but mostly lack of testers. Feel free to 283submit the improvement patch to the author. 284 285 286Direct Debugging 287~~~~~~~~~~~~~~~~ 288If no model option gives you a better result, and you are a tough guy 289to fight against evil, try debugging via hitting the raw HD-audio 290codec verbs to the device. Some tools are available: hda-emu and 291hda-analyzer. The detailed description is found in the sections 292below. You'd need to enable hwdep for using these tools. See "Kernel 293Configuration" section. 294 295 296OTHER ISSUES 297------------ 298 299Kernel Configuration 300~~~~~~~~~~~~~~~~~~~~ 301In general, I recommend you to enable the sound debug option, 302`CONFIG_SND_DEBUG=y`, no matter whether you are debugging or not. 303This enables snd_printd() macro and others, and you'll get additional 304kernel messages at probing. 305 306In addition, you can enable `CONFIG_SND_DEBUG_VERBOSE=y`. But this 307will give you far more messages. Thus turn this on only when you are 308sure to want it. 309 310Don't forget to turn on the appropriate `CONFIG_SND_HDA_CODEC_*` 311options. Note that each of them corresponds to the codec chip, not 312the controller chip. Thus, even if lspci shows the Nvidia controller, 313you may need to choose the option for other vendors. If you are 314unsure, just select all yes. 315 316`CONFIG_SND_HDA_HWDEP` is a useful option for debugging the driver. 317When this is enabled, the driver creates hardware-dependent devices 318(one per each codec), and you have a raw access to the device via 319these device files. For example, `hwC0D2` will be created for the 320codec slot #2 of the first card (#0). For debug-tools such as 321hda-verb and hda-analyzer, the hwdep device has to be enabled. 322Thus, it'd be better to turn this on always. 323 324`CONFIG_SND_HDA_RECONFIG` is a new option, and this depends on the 325hwdep option above. When enabled, you'll have some sysfs files under 326the corresponding hwdep directory. See "HD-audio reconfiguration" 327section below. 328 329`CONFIG_SND_HDA_POWER_SAVE` option enables the power-saving feature. 330See "Power-saving" section below. 331 332 333Codec Proc-File 334~~~~~~~~~~~~~~~ 335The codec proc-file is a treasure-chest for debugging HD-audio. 336It shows most of useful information of each codec widget. 337 338The proc file is located in /proc/asound/card*/codec#*, one file per 339each codec slot. You can know the codec vendor, product id and 340names, the type of each widget, capabilities and so on. 341This file, however, doesn't show the jack sensing state, so far. This 342is because the jack-sensing might be depending on the trigger state. 343 344This file will be picked up by the debug tools, and also it can be fed 345to the emulator as the primary codec information. See the debug tools 346section below. 347 348This proc file can be also used to check whether the generic parser is 349used. When the generic parser is used, the vendor/product ID name 350will appear as "Realtek ID 0262", instead of "Realtek ALC262". 351 352 353HD-Audio Reconfiguration 354~~~~~~~~~~~~~~~~~~~~~~~~ 355This is an experimental feature to allow you re-configure the HD-audio 356codec dynamically without reloading the driver. The following sysfs 357files are available under each codec-hwdep device directory (e.g. 358/sys/class/sound/hwC0D0): 359 360vendor_id:: 361 Shows the 32bit codec vendor-id hex number. You can change the 362 vendor-id value by writing to this file. 363subsystem_id:: 364 Shows the 32bit codec subsystem-id hex number. You can change the 365 subsystem-id value by writing to this file. 366revision_id:: 367 Shows the 32bit codec revision-id hex number. You can change the 368 revision-id value by writing to this file. 369afg:: 370 Shows the AFG ID. This is read-only. 371mfg:: 372 Shows the MFG ID. This is read-only. 373name:: 374 Shows the codec name string. Can be changed by writing to this 375 file. 376modelname:: 377 Shows the currently set `model` option. Can be changed by writing 378 to this file. 379init_verbs:: 380 The extra verbs to execute at initialization. You can add a verb by 381 writing to this file. Pass three numbers: nid, verb and parameter 382 (separated with a space). 383hints:: 384 Shows / stores hint strings for codec parsers for any use. 385 Its format is `key = value`. For example, passing `jack_detect = no` 386 will disable the jack detection of the machine completely. 387init_pin_configs:: 388 Shows the initial pin default config values set by BIOS. 389driver_pin_configs:: 390 Shows the pin default values set by the codec parser explicitly. 391 This doesn't show all pin values but only the changed values by 392 the parser. That is, if the parser doesn't change the pin default 393 config values by itself, this will contain nothing. 394user_pin_configs:: 395 Shows the pin default config values to override the BIOS setup. 396 Writing this (with two numbers, NID and value) appends the new 397 value. The given will be used instead of the initial BIOS value at 398 the next reconfiguration time. Note that this config will override 399 even the driver pin configs, too. 400reconfig:: 401 Triggers the codec re-configuration. When any value is written to 402 this file, the driver re-initialize and parses the codec tree 403 again. All the changes done by the sysfs entries above are taken 404 into account. 405clear:: 406 Resets the codec, removes the mixer elements and PCM stuff of the 407 specified codec, and clear all init verbs and hints. 408 409For example, when you want to change the pin default configuration 410value of the pin widget 0x14 to 0x9993013f, and let the driver 411re-configure based on that state, run like below: 412------------------------------------------------------------------------ 413 # echo 0x14 0x9993013f > /sys/class/sound/hwC0D0/user_pin_configs 414 # echo 1 > /sys/class/sound/hwC0D0/reconfig 415------------------------------------------------------------------------ 416 417 418Hint Strings 419~~~~~~~~~~~~ 420The codec parser have several switches and adjustment knobs for 421matching better with the actual codec or device behavior. Many of 422them can be adjusted dynamically via "hints" strings as mentioned in 423the section above. For example, by passing `jack_detect = no` string 424via sysfs or a patch file, you can disable the jack detection, thus 425the codec parser will skip the features like auto-mute or mic 426auto-switch. As a boolean value, either `yes`, `no`, `true`, `false`, 427`1` or `0` can be passed. 428 429The generic parser supports the following hints: 430 431- jack_detect (bool): specify whether the jack detection is available 432 at all on this machine; default true 433- inv_jack_detect (bool): indicates that the jack detection logic is 434 inverted 435- trigger_sense (bool): indicates that the jack detection needs the 436 explicit call of AC_VERB_SET_PIN_SENSE verb 437- inv_eapd (bool): indicates that the EAPD is implemented in the 438 inverted logic 439- pcm_format_first (bool): sets the PCM format before the stream tag 440 and channel ID 441- sticky_stream (bool): keep the PCM format, stream tag and ID as long 442 as possible; default true 443- spdif_status_reset (bool): reset the SPDIF status bits at each time 444 the SPDIF stream is set up 445- pin_amp_workaround (bool): the output pin may have multiple amp 446 values 447- single_adc_amp (bool): ADCs can have only single input amps 448- auto_mute (bool): enable/disable the headphone auto-mute feature; 449 default true 450- auto_mic (bool): enable/disable the mic auto-switch feature; default 451 true 452- line_in_auto_switch (bool): enable/disable the line-in auto-switch 453 feature; default false 454- need_dac_fix (bool): limits the DACs depending on the channel count 455- primary_hp (bool): probe headphone jacks as the primary outputs; 456 default true 457- multi_io (bool): try probing multi-I/O config (e.g. shared 458 line-in/surround, mic/clfe jacks) 459- multi_cap_vol (bool): provide multiple capture volumes 460- inv_dmic_split (bool): provide split internal mic volume/switch for 461 phase-inverted digital mics 462- indep_hp (bool): provide the independent headphone PCM stream and 463 the corresponding mixer control, if available 464- add_stereo_mix_input (bool): add the stereo mix (analog-loopback 465 mix) to the input mux if available 466- add_jack_modes (bool): add "xxx Jack Mode" enum controls to each 467 I/O jack for allowing to change the headphone amp and mic bias VREF 468 capabilities 469- power_save_node (bool): advanced power management for each widget, 470 controlling the power sate (D0/D3) of each widget node depending on 471 the actual pin and stream states 472- power_down_unused (bool): power down the unused widgets, a subset of 473 power_save_node, and will be dropped in future 474- add_hp_mic (bool): add the headphone to capture source if possible 475- hp_mic_detect (bool): enable/disable the hp/mic shared input for a 476 single built-in mic case; default true 477- mixer_nid (int): specifies the widget NID of the analog-loopback 478 mixer 479 480 481Early Patching 482~~~~~~~~~~~~~~ 483When CONFIG_SND_HDA_PATCH_LOADER=y is set, you can pass a "patch" as a 484firmware file for modifying the HD-audio setup before initializing the 485codec. This can work basically like the reconfiguration via sysfs in 486the above, but it does it before the first codec configuration. 487 488A patch file is a plain text file which looks like below: 489 490------------------------------------------------------------------------ 491 [codec] 492 0x12345678 0xabcd1234 2 493 494 [model] 495 auto 496 497 [pincfg] 498 0x12 0x411111f0 499 500 [verb] 501 0x20 0x500 0x03 502 0x20 0x400 0xff 503 504 [hint] 505 jack_detect = no 506------------------------------------------------------------------------ 507 508The file needs to have a line `[codec]`. The next line should contain 509three numbers indicating the codec vendor-id (0x12345678 in the 510example), the codec subsystem-id (0xabcd1234) and the address (2) of 511the codec. The rest patch entries are applied to this specified codec 512until another codec entry is given. Passing 0 or a negative number to 513the first or the second value will make the check of the corresponding 514field be skipped. It'll be useful for really broken devices that don't 515initialize SSID properly. 516 517The `[model]` line allows to change the model name of the each codec. 518In the example above, it will be changed to model=auto. 519Note that this overrides the module option. 520 521After the `[pincfg]` line, the contents are parsed as the initial 522default pin-configurations just like `user_pin_configs` sysfs above. 523The values can be shown in user_pin_configs sysfs file, too. 524 525Similarly, the lines after `[verb]` are parsed as `init_verbs` 526sysfs entries, and the lines after `[hint]` are parsed as `hints` 527sysfs entries, respectively. 528 529Another example to override the codec vendor id from 0x12345678 to 5300xdeadbeef is like below: 531------------------------------------------------------------------------ 532 [codec] 533 0x12345678 0xabcd1234 2 534 535 [vendor_id] 536 0xdeadbeef 537------------------------------------------------------------------------ 538 539In the similar way, you can override the codec subsystem_id via 540`[subsystem_id]`, the revision id via `[revision_id]` line. 541Also, the codec chip name can be rewritten via `[chip_name]` line. 542------------------------------------------------------------------------ 543 [codec] 544 0x12345678 0xabcd1234 2 545 546 [subsystem_id] 547 0xffff1111 548 549 [revision_id] 550 0x10 551 552 [chip_name] 553 My-own NEWS-0002 554------------------------------------------------------------------------ 555 556The hd-audio driver reads the file via request_firmware(). Thus, 557a patch file has to be located on the appropriate firmware path, 558typically, /lib/firmware. For example, when you pass the option 559`patch=hda-init.fw`, the file /lib/firmware/hda-init.fw must be 560present. 561 562The patch module option is specific to each card instance, and you 563need to give one file name for each instance, separated by commas. 564For example, if you have two cards, one for an on-board analog and one 565for an HDMI video board, you may pass patch option like below: 566------------------------------------------------------------------------ 567 options snd-hda-intel patch=on-board-patch,hdmi-patch 568------------------------------------------------------------------------ 569 570 571Power-Saving 572~~~~~~~~~~~~ 573The power-saving is a kind of auto-suspend of the device. When the 574device is inactive for a certain time, the device is automatically 575turned off to save the power. The time to go down is specified via 576`power_save` module option, and this option can be changed dynamically 577via sysfs. 578 579The power-saving won't work when the analog loopback is enabled on 580some codecs. Make sure that you mute all unneeded signal routes when 581you want the power-saving. 582 583The power-saving feature might cause audible click noises at each 584power-down/up depending on the device. Some of them might be 585solvable, but some are hard, I'm afraid. Some distros such as 586openSUSE enables the power-saving feature automatically when the power 587cable is unplugged. Thus, if you hear noises, suspect first the 588power-saving. See /sys/module/snd_hda_intel/parameters/power_save to 589check the current value. If it's non-zero, the feature is turned on. 590 591The recent kernel supports the runtime PM for the HD-audio controller 592chip, too. It means that the HD-audio controller is also powered up / 593down dynamically. The feature is enabled only for certain controller 594chips like Intel LynxPoint. You can enable/disable this feature 595forcibly by setting `power_save_controller` option, which is also 596available at /sys/module/snd_hda_intel/parameters directory. 597 598 599Tracepoints 600~~~~~~~~~~~ 601The hd-audio driver gives a few basic tracepoints. 602`hda:hda_send_cmd` traces each CORB write while `hda:hda_get_response` 603traces the response from RIRB (only when read from the codec driver). 604`hda:hda_bus_reset` traces the bus-reset due to fatal error, etc, 605`hda:hda_unsol_event` traces the unsolicited events, and 606`hda:hda_power_down` and `hda:hda_power_up` trace the power down/up 607via power-saving behavior. 608 609Enabling all tracepoints can be done like 610------------------------------------------------------------------------ 611 # echo 1 > /sys/kernel/debug/tracing/events/hda/enable 612------------------------------------------------------------------------ 613then after some commands, you can traces from 614/sys/kernel/debug/tracing/trace file. For example, when you want to 615trace what codec command is sent, enable the tracepoint like: 616------------------------------------------------------------------------ 617 # cat /sys/kernel/debug/tracing/trace 618 # tracer: nop 619 # 620 # TASK-PID CPU# TIMESTAMP FUNCTION 621 # | | | | | 622 <...>-7807 [002] 105147.774889: hda_send_cmd: [0:0] val=e3a019 623 <...>-7807 [002] 105147.774893: hda_send_cmd: [0:0] val=e39019 624 <...>-7807 [002] 105147.999542: hda_send_cmd: [0:0] val=e3a01a 625 <...>-7807 [002] 105147.999543: hda_send_cmd: [0:0] val=e3901a 626 <...>-26764 [001] 349222.837143: hda_send_cmd: [0:0] val=e3a019 627 <...>-26764 [001] 349222.837148: hda_send_cmd: [0:0] val=e39019 628 <...>-26764 [001] 349223.058539: hda_send_cmd: [0:0] val=e3a01a 629 <...>-26764 [001] 349223.058541: hda_send_cmd: [0:0] val=e3901a 630------------------------------------------------------------------------ 631Here `[0:0]` indicates the card number and the codec address, and 632`val` shows the value sent to the codec, respectively. The value is 633a packed value, and you can decode it via hda-decode-verb program 634included in hda-emu package below. For example, the value e3a019 is 635to set the left output-amp value to 25. 636------------------------------------------------------------------------ 637 % hda-decode-verb 0xe3a019 638 raw value = 0x00e3a019 639 cid = 0, nid = 0x0e, verb = 0x3a0, parm = 0x19 640 raw value: verb = 0x3a0, parm = 0x19 641 verbname = set_amp_gain_mute 642 amp raw val = 0xa019 643 output, left, idx=0, mute=0, val=25 644------------------------------------------------------------------------ 645 646 647Development Tree 648~~~~~~~~~~~~~~~~ 649The latest development codes for HD-audio are found on sound git tree: 650 651- git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git 652 653The master branch or for-next branches can be used as the main 654development branches in general while the development for the current 655and next kernels are found in for-linus and for-next branches, 656respectively. 657 658If you are using the latest Linus tree, it'd be better to pull the 659above GIT tree onto it. If you are using the older kernels, an easy 660way to try the latest ALSA code is to build from the snapshot 661tarball. There are daily tarballs and the latest snapshot tarball. 662All can be built just like normal alsa-driver release packages, that 663is, installed via the usual spells: configure, make and make 664install(-modules). See INSTALL in the package. The snapshot tarballs 665are found at: 666 667- ftp://ftp.suse.com/pub/people/tiwai/snapshot/ 668 669 670Sending a Bug Report 671~~~~~~~~~~~~~~~~~~~~ 672If any model or module options don't work for your device, it's time 673to send a bug report to the developers. Give the following in your 674bug report: 675 676- Hardware vendor, product and model names 677- Kernel version (and ALSA-driver version if you built externally) 678- `alsa-info.sh` output; run with `--no-upload` option. See the 679 section below about alsa-info 680 681If it's a regression, at best, send alsa-info outputs of both working 682and non-working kernels. This is really helpful because we can 683compare the codec registers directly. 684 685Send a bug report either the followings: 686 687kernel-bugzilla:: 688 https://bugzilla.kernel.org/ 689alsa-devel ML:: 690 alsa-devel@alsa-project.org 691 692 693DEBUG TOOLS 694----------- 695 696This section describes some tools available for debugging HD-audio 697problems. 698 699alsa-info 700~~~~~~~~~ 701The script `alsa-info.sh` is a very useful tool to gather the audio 702device information. You can fetch the latest version from: 703 704- http://www.alsa-project.org/alsa-info.sh 705 706Run this script as root, and it will gather the important information 707such as the module lists, module parameters, proc file contents 708including the codec proc files, mixer outputs and the control 709elements. As default, it will store the information onto a web server 710on alsa-project.org. But, if you send a bug report, it'd be better to 711run with `--no-upload` option, and attach the generated file. 712 713There are some other useful options. See `--help` option output for 714details. 715 716When a probe error occurs or when the driver obviously assigns a 717mismatched model, it'd be helpful to load the driver with 718`probe_only=1` option (at best after the cold reboot) and run 719alsa-info at this state. With this option, the driver won't configure 720the mixer and PCM but just tries to probe the codec slot. After 721probing, the proc file is available, so you can get the raw codec 722information before modified by the driver. Of course, the driver 723isn't usable with `probe_only=1`. But you can continue the 724configuration via hwdep sysfs file if hda-reconfig option is enabled. 725Using `probe_only` mask 2 skips the reset of HDA codecs (use 726`probe_only=3` as module option). The hwdep interface can be used 727to determine the BIOS codec initialization. 728 729 730hda-verb 731~~~~~~~~ 732hda-verb is a tiny program that allows you to access the HD-audio 733codec directly. You can execute a raw HD-audio codec verb with this. 734This program accesses the hwdep device, thus you need to enable the 735kernel config `CONFIG_SND_HDA_HWDEP=y` beforehand. 736 737The hda-verb program takes four arguments: the hwdep device file, the 738widget NID, the verb and the parameter. When you access to the codec 739on the slot 2 of the card 0, pass /dev/snd/hwC0D2 to the first 740argument, typically. (However, the real path name depends on the 741system.) 742 743The second parameter is the widget number-id to access. The third 744parameter can be either a hex/digit number or a string corresponding 745to a verb. Similarly, the last parameter is the value to write, or 746can be a string for the parameter type. 747 748------------------------------------------------------------------------ 749 % hda-verb /dev/snd/hwC0D0 0x12 0x701 2 750 nid = 0x12, verb = 0x701, param = 0x2 751 value = 0x0 752 753 % hda-verb /dev/snd/hwC0D0 0x0 PARAMETERS VENDOR_ID 754 nid = 0x0, verb = 0xf00, param = 0x0 755 value = 0x10ec0262 756 757 % hda-verb /dev/snd/hwC0D0 2 set_a 0xb080 758 nid = 0x2, verb = 0x300, param = 0xb080 759 value = 0x0 760------------------------------------------------------------------------ 761 762Although you can issue any verbs with this program, the driver state 763won't be always updated. For example, the volume values are usually 764cached in the driver, and thus changing the widget amp value directly 765via hda-verb won't change the mixer value. 766 767The hda-verb program is included now in alsa-tools: 768 769- git://git.alsa-project.org/alsa-tools.git 770 771Also, the old stand-alone package is found in the ftp directory: 772 773- ftp://ftp.suse.com/pub/people/tiwai/misc/ 774 775Also a git repository is available: 776 777- git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/hda-verb.git 778 779See README file in the tarball for more details about hda-verb 780program. 781 782 783hda-analyzer 784~~~~~~~~~~~~ 785hda-analyzer provides a graphical interface to access the raw HD-audio 786control, based on pyGTK2 binding. It's a more powerful version of 787hda-verb. The program gives you an easy-to-use GUI stuff for showing 788the widget information and adjusting the amp values, as well as the 789proc-compatible output. 790 791The hda-analyzer: 792 793- http://git.alsa-project.org/?p=alsa.git;a=tree;f=hda-analyzer 794 795is a part of alsa.git repository in alsa-project.org: 796 797- git://git.alsa-project.org/alsa.git 798 799Codecgraph 800~~~~~~~~~~ 801Codecgraph is a utility program to generate a graph and visualizes the 802codec-node connection of a codec chip. It's especially useful when 803you analyze or debug a codec without a proper datasheet. The program 804parses the given codec proc file and converts to SVG via graphiz 805program. 806 807The tarball and GIT trees are found in the web page at: 808 809- http://helllabs.org/codecgraph/ 810 811 812hda-emu 813~~~~~~~ 814hda-emu is an HD-audio emulator. The main purpose of this program is 815to debug an HD-audio codec without the real hardware. Thus, it 816doesn't emulate the behavior with the real audio I/O, but it just 817dumps the codec register changes and the ALSA-driver internal changes 818at probing and operating the HD-audio driver. 819 820The program requires a codec proc-file to simulate. Get a proc file 821for the target codec beforehand, or pick up an example codec from the 822codec proc collections in the tarball. Then, run the program with the 823proc file, and the hda-emu program will start parsing the codec file 824and simulates the HD-audio driver: 825 826------------------------------------------------------------------------ 827 % hda-emu codecs/stac9200-dell-d820-laptop 828 # Parsing.. 829 hda_codec: Unknown model for STAC9200, using BIOS defaults 830 hda_codec: pin nid 08 bios pin config 40c003fa 831 .... 832------------------------------------------------------------------------ 833 834The program gives you only a very dumb command-line interface. You 835can get a proc-file dump at the current state, get a list of control 836(mixer) elements, set/get the control element value, simulate the PCM 837operation, the jack plugging simulation, etc. 838 839The package is found in: 840 841- ftp://ftp.suse.com/pub/people/tiwai/misc/ 842 843A git repository is available: 844 845- git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/hda-emu.git 846 847See README file in the tarball for more details about hda-emu 848program. 849 850 851hda-jack-retask 852~~~~~~~~~~~~~~~ 853hda-jack-retask is a user-friendly GUI program to manipulate the 854HD-audio pin control for jack retasking. If you have a problem about 855the jack assignment, try this program and check whether you can get 856useful results. Once when you figure out the proper pin assignment, 857it can be fixed either in the driver code statically or via passing a 858firmware patch file (see "Early Patching" section). 859 860The program is included in alsa-tools now: 861 862- git://git.alsa-project.org/alsa-tools.git 863 864