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diff --git a/Documentation/sound/hd-audio/notes.rst b/Documentation/sound/hd-audio/notes.rst new file mode 100644 index 000000000..9f7347830 --- /dev/null +++ b/Documentation/sound/hd-audio/notes.rst @@ -0,0 +1,882 @@ +============================= +More Notes on HD-Audio Driver +============================= + +Takashi Iwai <tiwai@suse.de> + + +General +======= + +HD-audio is the new standard on-board audio component on modern PCs +after AC97. Although Linux has been supporting HD-audio since long +time ago, there are often problems with new machines. A part of the +problem is broken BIOS, and the rest is the driver implementation. +This document explains the brief trouble-shooting and debugging +methods for the HD-audio hardware. + +The HD-audio component consists of two parts: the controller chip and +the codec chips on the HD-audio bus. Linux provides a single driver +for all controllers, snd-hda-intel. Although the driver name contains +a word of a well-known hardware vendor, it's not specific to it but for +all controller chips by other companies. Since the HD-audio +controllers are supposed to be compatible, the single snd-hda-driver +should work in most cases. But, not surprisingly, there are known +bugs and issues specific to each controller type. The snd-hda-intel +driver has a bunch of workarounds for these as described below. + +A controller may have multiple codecs. Usually you have one audio +codec and optionally one modem codec. In theory, there might be +multiple audio codecs, e.g. for analog and digital outputs, and the +driver might not work properly because of conflict of mixer elements. +This should be fixed in future if such hardware really exists. + +The snd-hda-intel driver has several different codec parsers depending +on the codec. It has a generic parser as a fallback, but this +functionality is fairly limited until now. Instead of the generic +parser, usually the codec-specific parser (coded in patch_*.c) is used +for the codec-specific implementations. The details about the +codec-specific problems are explained in the later sections. + +If you are interested in the deep debugging of HD-audio, read the +HD-audio specification at first. The specification is found on +Intel's web page, for example: + +* http://www.intel.com/standards/hdaudio/ + + +HD-Audio Controller +=================== + +DMA-Position Problem +-------------------- +The most common problem of the controller is the inaccurate DMA +pointer reporting. The DMA pointer for playback and capture can be +read in two ways, either via a LPIB register or via a position-buffer +map. As default the driver tries to read from the io-mapped +position-buffer, and falls back to LPIB if the position-buffer appears +dead. However, this detection isn't perfect on some devices. In such +a case, you can change the default method via ``position_fix`` option. + +``position_fix=1`` means to use LPIB method explicitly. +``position_fix=2`` means to use the position-buffer. +``position_fix=3`` means to use a combination of both methods, needed +for some VIA controllers. The capture stream position is corrected +by comparing both LPIB and position-buffer values. +``position_fix=4`` is another combination available for all controllers, +and uses LPIB for the playback and the position-buffer for the capture +streams. +0 is the default value for all other +controllers, the automatic check and fallback to LPIB as described in +the above. If you get a problem of repeated sounds, this option might +help. + +In addition to that, every controller is known to be broken regarding +the wake-up timing. It wakes up a few samples before actually +processing the data on the buffer. This caused a lot of problems, for +example, with ALSA dmix or JACK. Since 2.6.27 kernel, the driver puts +an artificial delay to the wake up timing. This delay is controlled +via ``bdl_pos_adj`` option. + +When ``bdl_pos_adj`` is a negative value (as default), it's assigned to +an appropriate value depending on the controller chip. For Intel +chips, it'd be 1 while it'd be 32 for others. Usually this works. +Only in case it doesn't work and you get warning messages, you should +change this parameter to other values. + + +Codec-Probing Problem +--------------------- +A less often but a more severe problem is the codec probing. When +BIOS reports the available codec slots wrongly, the driver gets +confused and tries to access the non-existing codec slot. This often +results in the total screw-up, and destructs the further communication +with the codec chips. The symptom appears usually as error messages +like: +:: + + hda_intel: azx_get_response timeout, switching to polling mode: + last cmd=0x12345678 + hda_intel: azx_get_response timeout, switching to single_cmd mode: + last cmd=0x12345678 + +The first line is a warning, and this is usually relatively harmless. +It means that the codec response isn't notified via an IRQ. The +driver uses explicit polling method to read the response. It gives +very slight CPU overhead, but you'd unlikely notice it. + +The second line is, however, a fatal error. If this happens, usually +it means that something is really wrong. Most likely you are +accessing a non-existing codec slot. + +Thus, if the second error message appears, try to narrow the probed +codec slots via ``probe_mask`` option. It's a bitmask, and each bit +corresponds to the codec slot. For example, to probe only the first +slot, pass ``probe_mask=1``. For the first and the third slots, pass +``probe_mask=5`` (where 5 = 1 | 4), and so on. + +Since 2.6.29 kernel, the driver has a more robust probing method, so +this error might happen rarely, though. + +On a machine with a broken BIOS, sometimes you need to force the +driver to probe the codec slots the hardware doesn't report for use. +In such a case, turn the bit 8 (0x100) of ``probe_mask`` option on. +Then the rest 8 bits are passed as the codec slots to probe +unconditionally. For example, ``probe_mask=0x103`` will force to probe +the codec slots 0 and 1 no matter what the hardware reports. + + +Interrupt Handling +------------------ +HD-audio driver uses MSI as default (if available) since 2.6.33 +kernel as MSI works better on some machines, and in general, it's +better for performance. However, Nvidia controllers showed bad +regressions with MSI (especially in a combination with AMD chipset), +thus we disabled MSI for them. + +There seem also still other devices that don't work with MSI. If you +see a regression wrt the sound quality (stuttering, etc) or a lock-up +in the recent kernel, try to pass ``enable_msi=0`` option to disable +MSI. If it works, you can add the known bad device to the blacklist +defined in hda_intel.c. In such a case, please report and give the +patch back to the upstream developer. + + +HD-Audio Codec +============== + +Model Option +------------ +The most common problem regarding the HD-audio driver is the +unsupported codec features or the mismatched device configuration. +Most of codec-specific code has several preset models, either to +override the BIOS setup or to provide more comprehensive features. + +The driver checks PCI SSID and looks through the static configuration +table until any matching entry is found. If you have a new machine, +you may see a message like below: +:: + + hda_codec: ALC880: BIOS auto-probing. + +Meanwhile, in the earlier versions, you would see a message like: +:: + + hda_codec: Unknown model for ALC880, trying auto-probe from BIOS... + +Even if you see such a message, DON'T PANIC. Take a deep breath and +keep your towel. First of all, it's an informational message, no +warning, no error. This means that the PCI SSID of your device isn't +listed in the known preset model (white-)list. But, this doesn't mean +that the driver is broken. Many codec-drivers provide the automatic +configuration mechanism based on the BIOS setup. + +The HD-audio codec has usually "pin" widgets, and BIOS sets the default +configuration of each pin, which indicates the location, the +connection type, the jack color, etc. The HD-audio driver can guess +the right connection judging from these default configuration values. +However -- some codec-support codes, such as patch_analog.c, don't +support the automatic probing (yet as of 2.6.28). And, BIOS is often, +yes, pretty often broken. It sets up wrong values and screws up the +driver. + +The preset model (or recently called as "fix-up") is provided +basically to overcome such a situation. When the matching preset +model is found in the white-list, the driver assumes the static +configuration of that preset with the correct pin setup, etc. +Thus, if you have a newer machine with a slightly different PCI SSID +(or codec SSID) from the existing one, you may have a good chance to +re-use the same model. You can pass the ``model`` option to specify the +preset model instead of PCI (and codec-) SSID look-up. + +What ``model`` option values are available depends on the codec chip. +Check your codec chip from the codec proc file (see "Codec Proc-File" +section below). It will show the vendor/product name of your codec +chip. Then, see Documentation/sound/hd-audio/models.rst file, +the section of HD-audio driver. You can find a list of codecs +and ``model`` options belonging to each codec. For example, for Realtek +ALC262 codec chip, pass ``model=ultra`` for devices that are compatible +with Samsung Q1 Ultra. + +Thus, the first thing you can do for any brand-new, unsupported and +non-working HD-audio hardware is to check HD-audio codec and several +different ``model`` option values. If you have any luck, some of them +might suit with your device well. + +There are a few special model option values: + +* when 'nofixup' is passed, the device-specific fixups in the codec + parser are skipped. +* when ``generic`` is passed, the codec-specific parser is skipped and + only the generic parser is used. + + +Speaker and Headphone Output +---------------------------- +One of the most frequent (and obvious) bugs with HD-audio is the +silent output from either or both of a built-in speaker and a +headphone jack. In general, you should try a headphone output at +first. A speaker output often requires more additional controls like +the external amplifier bits. Thus a headphone output has a slightly +better chance. + +Before making a bug report, double-check whether the mixer is set up +correctly. The recent version of snd-hda-intel driver provides mostly +"Master" volume control as well as "Front" volume (where Front +indicates the front-channels). In addition, there can be individual +"Headphone" and "Speaker" controls. + +Ditto for the speaker output. There can be "External Amplifier" +switch on some codecs. Turn on this if present. + +Another related problem is the automatic mute of speaker output by +headphone plugging. This feature is implemented in most cases, but +not on every preset model or codec-support code. + +In anyway, try a different model option if you have such a problem. +Some other models may match better and give you more matching +functionality. If none of the available models works, send a bug +report. See the bug report section for details. + +If you are masochistic enough to debug the driver problem, note the +following: + +* The speaker (and the headphone, too) output often requires the + external amplifier. This can be set usually via EAPD verb or a + certain GPIO. If the codec pin supports EAPD, you have a better + chance via SET_EAPD_BTL verb (0x70c). On others, GPIO pin (mostly + it's either GPIO0 or GPIO1) may turn on/off EAPD. +* Some Realtek codecs require special vendor-specific coefficients to + turn on the amplifier. See patch_realtek.c. +* IDT codecs may have extra power-enable/disable controls on each + analog pin. See patch_sigmatel.c. +* Very rare but some devices don't accept the pin-detection verb until + triggered. Issuing GET_PIN_SENSE verb (0xf09) may result in the + codec-communication stall. Some examples are found in + patch_realtek.c. + + +Capture Problems +---------------- +The capture problems are often because of missing setups of mixers. +Thus, before submitting a bug report, make sure that you set up the +mixer correctly. For example, both "Capture Volume" and "Capture +Switch" have to be set properly in addition to the right "Capture +Source" or "Input Source" selection. Some devices have "Mic Boost" +volume or switch. + +When the PCM device is opened via "default" PCM (without pulse-audio +plugin), you'll likely have "Digital Capture Volume" control as well. +This is provided for the extra gain/attenuation of the signal in +software, especially for the inputs without the hardware volume +control such as digital microphones. Unless really needed, this +should be set to exactly 50%, corresponding to 0dB -- neither extra +gain nor attenuation. When you use "hw" PCM, i.e., a raw access PCM, +this control will have no influence, though. + +It's known that some codecs / devices have fairly bad analog circuits, +and the recorded sound contains a certain DC-offset. This is no bug +of the driver. + +Most of modern laptops have no analog CD-input connection. Thus, the +recording from CD input won't work in many cases although the driver +provides it as the capture source. Use CDDA instead. + +The automatic switching of the built-in and external mic per plugging +is implemented on some codec models but not on every model. Partly +because of my laziness but mostly lack of testers. Feel free to +submit the improvement patch to the author. + + +Direct Debugging +---------------- +If no model option gives you a better result, and you are a tough guy +to fight against evil, try debugging via hitting the raw HD-audio +codec verbs to the device. Some tools are available: hda-emu and +hda-analyzer. The detailed description is found in the sections +below. You'd need to enable hwdep for using these tools. See "Kernel +Configuration" section. + + +Other Issues +============ + +Kernel Configuration +-------------------- +In general, I recommend you to enable the sound debug option, +``CONFIG_SND_DEBUG=y``, no matter whether you are debugging or not. +This enables snd_printd() macro and others, and you'll get additional +kernel messages at probing. + +In addition, you can enable ``CONFIG_SND_DEBUG_VERBOSE=y``. But this +will give you far more messages. Thus turn this on only when you are +sure to want it. + +Don't forget to turn on the appropriate ``CONFIG_SND_HDA_CODEC_*`` +options. Note that each of them corresponds to the codec chip, not +the controller chip. Thus, even if lspci shows the Nvidia controller, +you may need to choose the option for other vendors. If you are +unsure, just select all yes. + +``CONFIG_SND_HDA_HWDEP`` is a useful option for debugging the driver. +When this is enabled, the driver creates hardware-dependent devices +(one per each codec), and you have a raw access to the device via +these device files. For example, ``hwC0D2`` will be created for the +codec slot #2 of the first card (#0). For debug-tools such as +hda-verb and hda-analyzer, the hwdep device has to be enabled. +Thus, it'd be better to turn this on always. + +``CONFIG_SND_HDA_RECONFIG`` is a new option, and this depends on the +hwdep option above. When enabled, you'll have some sysfs files under +the corresponding hwdep directory. See "HD-audio reconfiguration" +section below. + +``CONFIG_SND_HDA_POWER_SAVE`` option enables the power-saving feature. +See "Power-saving" section below. + + +Codec Proc-File +--------------- +The codec proc-file is a treasure-chest for debugging HD-audio. +It shows most of useful information of each codec widget. + +The proc file is located in /proc/asound/card*/codec#*, one file per +each codec slot. You can know the codec vendor, product id and +names, the type of each widget, capabilities and so on. +This file, however, doesn't show the jack sensing state, so far. This +is because the jack-sensing might be depending on the trigger state. + +This file will be picked up by the debug tools, and also it can be fed +to the emulator as the primary codec information. See the debug tools +section below. + +This proc file can be also used to check whether the generic parser is +used. When the generic parser is used, the vendor/product ID name +will appear as "Realtek ID 0262", instead of "Realtek ALC262". + + +HD-Audio Reconfiguration +------------------------ +This is an experimental feature to allow you re-configure the HD-audio +codec dynamically without reloading the driver. The following sysfs +files are available under each codec-hwdep device directory (e.g. +/sys/class/sound/hwC0D0): + +vendor_id + Shows the 32bit codec vendor-id hex number. You can change the + vendor-id value by writing to this file. +subsystem_id + Shows the 32bit codec subsystem-id hex number. You can change the + subsystem-id value by writing to this file. +revision_id + Shows the 32bit codec revision-id hex number. You can change the + revision-id value by writing to this file. +afg + Shows the AFG ID. This is read-only. +mfg + Shows the MFG ID. This is read-only. +name + Shows the codec name string. Can be changed by writing to this + file. +modelname + Shows the currently set ``model`` option. Can be changed by writing + to this file. +init_verbs + The extra verbs to execute at initialization. You can add a verb by + writing to this file. Pass three numbers: nid, verb and parameter + (separated with a space). +hints + Shows / stores hint strings for codec parsers for any use. + Its format is ``key = value``. For example, passing ``jack_detect = no`` + will disable the jack detection of the machine completely. +init_pin_configs + Shows the initial pin default config values set by BIOS. +driver_pin_configs + Shows the pin default values set by the codec parser explicitly. + This doesn't show all pin values but only the changed values by + the parser. That is, if the parser doesn't change the pin default + config values by itself, this will contain nothing. +user_pin_configs + Shows the pin default config values to override the BIOS setup. + Writing this (with two numbers, NID and value) appends the new + value. The given will be used instead of the initial BIOS value at + the next reconfiguration time. Note that this config will override + even the driver pin configs, too. +reconfig + Triggers the codec re-configuration. When any value is written to + this file, the driver re-initialize and parses the codec tree + again. All the changes done by the sysfs entries above are taken + into account. +clear + Resets the codec, removes the mixer elements and PCM stuff of the + specified codec, and clear all init verbs and hints. + +For example, when you want to change the pin default configuration +value of the pin widget 0x14 to 0x9993013f, and let the driver +re-configure based on that state, run like below: +:: + + # echo 0x14 0x9993013f > /sys/class/sound/hwC0D0/user_pin_configs + # echo 1 > /sys/class/sound/hwC0D0/reconfig + + +Hint Strings +------------ +The codec parser have several switches and adjustment knobs for +matching better with the actual codec or device behavior. Many of +them can be adjusted dynamically via "hints" strings as mentioned in +the section above. For example, by passing ``jack_detect = no`` string +via sysfs or a patch file, you can disable the jack detection, thus +the codec parser will skip the features like auto-mute or mic +auto-switch. As a boolean value, either ``yes``, ``no``, ``true``, ``false``, +``1`` or ``0`` can be passed. + +The generic parser supports the following hints: + +jack_detect (bool) + specify whether the jack detection is available at all on this + machine; default true +inv_jack_detect (bool) + indicates that the jack detection logic is inverted +trigger_sense (bool) + indicates that the jack detection needs the explicit call of + AC_VERB_SET_PIN_SENSE verb +inv_eapd (bool) + indicates that the EAPD is implemented in the inverted logic +pcm_format_first (bool) + sets the PCM format before the stream tag and channel ID +sticky_stream (bool) + keep the PCM format, stream tag and ID as long as possible; + default true +spdif_status_reset (bool) + reset the SPDIF status bits at each time the SPDIF stream is set + up +pin_amp_workaround (bool) + the output pin may have multiple amp values +single_adc_amp (bool) + ADCs can have only single input amps +auto_mute (bool) + enable/disable the headphone auto-mute feature; default true +auto_mic (bool) + enable/disable the mic auto-switch feature; default true +line_in_auto_switch (bool) + enable/disable the line-in auto-switch feature; default false +need_dac_fix (bool) + limits the DACs depending on the channel count +primary_hp (bool) + probe headphone jacks as the primary outputs; default true +multi_io (bool) + try probing multi-I/O config (e.g. shared line-in/surround, + mic/clfe jacks) +multi_cap_vol (bool) + provide multiple capture volumes +inv_dmic_split (bool) + provide split internal mic volume/switch for phase-inverted + digital mics +indep_hp (bool) + provide the independent headphone PCM stream and the corresponding + mixer control, if available +add_stereo_mix_input (bool) + add the stereo mix (analog-loopback mix) to the input mux if + available +add_jack_modes (bool) + add "xxx Jack Mode" enum controls to each I/O jack for allowing to + change the headphone amp and mic bias VREF capabilities +power_save_node (bool) + advanced power management for each widget, controlling the power + sate (D0/D3) of each widget node depending on the actual pin and + stream states +power_down_unused (bool) + power down the unused widgets, a subset of power_save_node, and + will be dropped in future +add_hp_mic (bool) + add the headphone to capture source if possible +hp_mic_detect (bool) + enable/disable the hp/mic shared input for a single built-in mic + case; default true +vmaster (bool) + enable/disable the virtual Master control; default true +mixer_nid (int) + specifies the widget NID of the analog-loopback mixer + + +Early Patching +-------------- +When ``CONFIG_SND_HDA_PATCH_LOADER=y`` is set, you can pass a "patch" +as a firmware file for modifying the HD-audio setup before +initializing the codec. This can work basically like the +reconfiguration via sysfs in the above, but it does it before the +first codec configuration. + +A patch file is a plain text file which looks like below: + +:: + + [codec] + 0x12345678 0xabcd1234 2 + + [model] + auto + + [pincfg] + 0x12 0x411111f0 + + [verb] + 0x20 0x500 0x03 + 0x20 0x400 0xff + + [hint] + jack_detect = no + + +The file needs to have a line ``[codec]``. The next line should contain +three numbers indicating the codec vendor-id (0x12345678 in the +example), the codec subsystem-id (0xabcd1234) and the address (2) of +the codec. The rest patch entries are applied to this specified codec +until another codec entry is given. Passing 0 or a negative number to +the first or the second value will make the check of the corresponding +field be skipped. It'll be useful for really broken devices that don't +initialize SSID properly. + +The ``[model]`` line allows to change the model name of the each codec. +In the example above, it will be changed to model=auto. +Note that this overrides the module option. + +After the ``[pincfg]`` line, the contents are parsed as the initial +default pin-configurations just like ``user_pin_configs`` sysfs above. +The values can be shown in user_pin_configs sysfs file, too. + +Similarly, the lines after ``[verb]`` are parsed as ``init_verbs`` +sysfs entries, and the lines after ``[hint]`` are parsed as ``hints`` +sysfs entries, respectively. + +Another example to override the codec vendor id from 0x12345678 to +0xdeadbeef is like below: +:: + + [codec] + 0x12345678 0xabcd1234 2 + + [vendor_id] + 0xdeadbeef + + +In the similar way, you can override the codec subsystem_id via +``[subsystem_id]``, the revision id via ``[revision_id]`` line. +Also, the codec chip name can be rewritten via ``[chip_name]`` line. +:: + + [codec] + 0x12345678 0xabcd1234 2 + + [subsystem_id] + 0xffff1111 + + [revision_id] + 0x10 + + [chip_name] + My-own NEWS-0002 + + +The hd-audio driver reads the file via request_firmware(). Thus, +a patch file has to be located on the appropriate firmware path, +typically, /lib/firmware. For example, when you pass the option +``patch=hda-init.fw``, the file /lib/firmware/hda-init.fw must be +present. + +The patch module option is specific to each card instance, and you +need to give one file name for each instance, separated by commas. +For example, if you have two cards, one for an on-board analog and one +for an HDMI video board, you may pass patch option like below: +:: + + options snd-hda-intel patch=on-board-patch,hdmi-patch + + +Power-Saving +------------ +The power-saving is a kind of auto-suspend of the device. When the +device is inactive for a certain time, the device is automatically +turned off to save the power. The time to go down is specified via +``power_save`` module option, and this option can be changed dynamically +via sysfs. + +The power-saving won't work when the analog loopback is enabled on +some codecs. Make sure that you mute all unneeded signal routes when +you want the power-saving. + +The power-saving feature might cause audible click noises at each +power-down/up depending on the device. Some of them might be +solvable, but some are hard, I'm afraid. Some distros such as +openSUSE enables the power-saving feature automatically when the power +cable is unplugged. Thus, if you hear noises, suspect first the +power-saving. See /sys/module/snd_hda_intel/parameters/power_save to +check the current value. If it's non-zero, the feature is turned on. + +The recent kernel supports the runtime PM for the HD-audio controller +chip, too. It means that the HD-audio controller is also powered up / +down dynamically. The feature is enabled only for certain controller +chips like Intel LynxPoint. You can enable/disable this feature +forcibly by setting ``power_save_controller`` option, which is also +available at /sys/module/snd_hda_intel/parameters directory. + + +Tracepoints +----------- +The hd-audio driver gives a few basic tracepoints. +``hda:hda_send_cmd`` traces each CORB write while ``hda:hda_get_response`` +traces the response from RIRB (only when read from the codec driver). +``hda:hda_bus_reset`` traces the bus-reset due to fatal error, etc, +``hda:hda_unsol_event`` traces the unsolicited events, and +``hda:hda_power_down`` and ``hda:hda_power_up`` trace the power down/up +via power-saving behavior. + +Enabling all tracepoints can be done like +:: + + # echo 1 > /sys/kernel/debug/tracing/events/hda/enable + +then after some commands, you can traces from +/sys/kernel/debug/tracing/trace file. For example, when you want to +trace what codec command is sent, enable the tracepoint like: +:: + + # cat /sys/kernel/debug/tracing/trace + # tracer: nop + # + # TASK-PID CPU# TIMESTAMP FUNCTION + # | | | | | + <...>-7807 [002] 105147.774889: hda_send_cmd: [0:0] val=e3a019 + <...>-7807 [002] 105147.774893: hda_send_cmd: [0:0] val=e39019 + <...>-7807 [002] 105147.999542: hda_send_cmd: [0:0] val=e3a01a + <...>-7807 [002] 105147.999543: hda_send_cmd: [0:0] val=e3901a + <...>-26764 [001] 349222.837143: hda_send_cmd: [0:0] val=e3a019 + <...>-26764 [001] 349222.837148: hda_send_cmd: [0:0] val=e39019 + <...>-26764 [001] 349223.058539: hda_send_cmd: [0:0] val=e3a01a + <...>-26764 [001] 349223.058541: hda_send_cmd: [0:0] val=e3901a + +Here ``[0:0]`` indicates the card number and the codec address, and +``val`` shows the value sent to the codec, respectively. The value is +a packed value, and you can decode it via hda-decode-verb program +included in hda-emu package below. For example, the value e3a019 is +to set the left output-amp value to 25. +:: + + % hda-decode-verb 0xe3a019 + raw value = 0x00e3a019 + cid = 0, nid = 0x0e, verb = 0x3a0, parm = 0x19 + raw value: verb = 0x3a0, parm = 0x19 + verbname = set_amp_gain_mute + amp raw val = 0xa019 + output, left, idx=0, mute=0, val=25 + + +Development Tree +---------------- +The latest development codes for HD-audio are found on sound git tree: + +* git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git + +The master branch or for-next branches can be used as the main +development branches in general while the development for the current +and next kernels are found in for-linus and for-next branches, +respectively. + + +Sending a Bug Report +-------------------- +If any model or module options don't work for your device, it's time +to send a bug report to the developers. Give the following in your +bug report: + +* Hardware vendor, product and model names +* Kernel version (and ALSA-driver version if you built externally) +* ``alsa-info.sh`` output; run with ``--no-upload`` option. See the + section below about alsa-info + +If it's a regression, at best, send alsa-info outputs of both working +and non-working kernels. This is really helpful because we can +compare the codec registers directly. + +Send a bug report either the following: + +kernel-bugzilla + https://bugzilla.kernel.org/ +alsa-devel ML + alsa-devel@alsa-project.org + + +Debug Tools +=========== + +This section describes some tools available for debugging HD-audio +problems. + +alsa-info +--------- +The script ``alsa-info.sh`` is a very useful tool to gather the audio +device information. It's included in alsa-utils package. The latest +version can be found on git repository: + +* git://git.alsa-project.org/alsa-utils.git + +The script can be fetched directly from the following URL, too: + +* http://www.alsa-project.org/alsa-info.sh + +Run this script as root, and it will gather the important information +such as the module lists, module parameters, proc file contents +including the codec proc files, mixer outputs and the control +elements. As default, it will store the information onto a web server +on alsa-project.org. But, if you send a bug report, it'd be better to +run with ``--no-upload`` option, and attach the generated file. + +There are some other useful options. See ``--help`` option output for +details. + +When a probe error occurs or when the driver obviously assigns a +mismatched model, it'd be helpful to load the driver with +``probe_only=1`` option (at best after the cold reboot) and run +alsa-info at this state. With this option, the driver won't configure +the mixer and PCM but just tries to probe the codec slot. After +probing, the proc file is available, so you can get the raw codec +information before modified by the driver. Of course, the driver +isn't usable with ``probe_only=1``. But you can continue the +configuration via hwdep sysfs file if hda-reconfig option is enabled. +Using ``probe_only`` mask 2 skips the reset of HDA codecs (use +``probe_only=3`` as module option). The hwdep interface can be used +to determine the BIOS codec initialization. + + +hda-verb +-------- +hda-verb is a tiny program that allows you to access the HD-audio +codec directly. You can execute a raw HD-audio codec verb with this. +This program accesses the hwdep device, thus you need to enable the +kernel config ``CONFIG_SND_HDA_HWDEP=y`` beforehand. + +The hda-verb program takes four arguments: the hwdep device file, the +widget NID, the verb and the parameter. When you access to the codec +on the slot 2 of the card 0, pass /dev/snd/hwC0D2 to the first +argument, typically. (However, the real path name depends on the +system.) + +The second parameter is the widget number-id to access. The third +parameter can be either a hex/digit number or a string corresponding +to a verb. Similarly, the last parameter is the value to write, or +can be a string for the parameter type. + +:: + + % hda-verb /dev/snd/hwC0D0 0x12 0x701 2 + nid = 0x12, verb = 0x701, param = 0x2 + value = 0x0 + + % hda-verb /dev/snd/hwC0D0 0x0 PARAMETERS VENDOR_ID + nid = 0x0, verb = 0xf00, param = 0x0 + value = 0x10ec0262 + + % hda-verb /dev/snd/hwC0D0 2 set_a 0xb080 + nid = 0x2, verb = 0x300, param = 0xb080 + value = 0x0 + + +Although you can issue any verbs with this program, the driver state +won't be always updated. For example, the volume values are usually +cached in the driver, and thus changing the widget amp value directly +via hda-verb won't change the mixer value. + +The hda-verb program is included now in alsa-tools: + +* git://git.alsa-project.org/alsa-tools.git + +Also, the old stand-alone package is found in the ftp directory: + +* ftp://ftp.suse.com/pub/people/tiwai/misc/ + +Also a git repository is available: + +* git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/hda-verb.git + +See README file in the tarball for more details about hda-verb +program. + + +hda-analyzer +------------ +hda-analyzer provides a graphical interface to access the raw HD-audio +control, based on pyGTK2 binding. It's a more powerful version of +hda-verb. The program gives you an easy-to-use GUI stuff for showing +the widget information and adjusting the amp values, as well as the +proc-compatible output. + +The hda-analyzer: + +* http://git.alsa-project.org/?p=alsa.git;a=tree;f=hda-analyzer + +is a part of alsa.git repository in alsa-project.org: + +* git://git.alsa-project.org/alsa.git + +Codecgraph +---------- +Codecgraph is a utility program to generate a graph and visualizes the +codec-node connection of a codec chip. It's especially useful when +you analyze or debug a codec without a proper datasheet. The program +parses the given codec proc file and converts to SVG via graphiz +program. + +The tarball and GIT trees are found in the web page at: + +* http://helllabs.org/codecgraph/ + + +hda-emu +------- +hda-emu is an HD-audio emulator. The main purpose of this program is +to debug an HD-audio codec without the real hardware. Thus, it +doesn't emulate the behavior with the real audio I/O, but it just +dumps the codec register changes and the ALSA-driver internal changes +at probing and operating the HD-audio driver. + +The program requires a codec proc-file to simulate. Get a proc file +for the target codec beforehand, or pick up an example codec from the +codec proc collections in the tarball. Then, run the program with the +proc file, and the hda-emu program will start parsing the codec file +and simulates the HD-audio driver: + +:: + + % hda-emu codecs/stac9200-dell-d820-laptop + # Parsing.. + hda_codec: Unknown model for STAC9200, using BIOS defaults + hda_codec: pin nid 08 bios pin config 40c003fa + .... + + +The program gives you only a very dumb command-line interface. You +can get a proc-file dump at the current state, get a list of control +(mixer) elements, set/get the control element value, simulate the PCM +operation, the jack plugging simulation, etc. + +The program is found in the git repository below: + +* git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/hda-emu.git + +See README file in the repository for more details about hda-emu +program. + + +hda-jack-retask +--------------- +hda-jack-retask is a user-friendly GUI program to manipulate the +HD-audio pin control for jack retasking. If you have a problem about +the jack assignment, try this program and check whether you can get +useful results. Once when you figure out the proper pin assignment, +it can be fixed either in the driver code statically or via passing a +firmware patch file (see "Early Patching" section). + +The program is included in alsa-tools now: + +* git://git.alsa-project.org/alsa-tools.git |