683 lines
28 KiB
Plaintext
683 lines
28 KiB
Plaintext
MORE NOTES ON HD-AUDIO DRIVER
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=============================
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Takashi Iwai <tiwai@suse.de>
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GENERAL
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-------
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HD-audio is the new standard on-board audio component on modern PCs
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after AC97. Although Linux has been supporting HD-audio since long
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time ago, there are often problems with new machines. A part of the
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problem is broken BIOS, and the rest is the driver implementation.
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This document explains the brief trouble-shooting and debugging
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methods for the HD-audio hardware.
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The HD-audio component consists of two parts: the controller chip and
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the codec chips on the HD-audio bus. Linux provides a single driver
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for all controllers, snd-hda-intel. Although the driver name contains
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a word of a well-known hardware vendor, it's not specific to it but for
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all controller chips by other companies. Since the HD-audio
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controllers are supposed to be compatible, the single snd-hda-driver
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should work in most cases. But, not surprisingly, there are known
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bugs and issues specific to each controller type. The snd-hda-intel
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driver has a bunch of workarounds for these as described below.
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A controller may have multiple codecs. Usually you have one audio
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codec and optionally one modem codec. In theory, there might be
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multiple audio codecs, e.g. for analog and digital outputs, and the
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driver might not work properly because of conflict of mixer elements.
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This should be fixed in future if such hardware really exists.
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The snd-hda-intel driver has several different codec parsers depending
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on the codec. It has a generic parser as a fallback, but this
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functionality is fairly limited until now. Instead of the generic
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parser, usually the codec-specific parser (coded in patch_*.c) is used
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for the codec-specific implementations. The details about the
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codec-specific problems are explained in the later sections.
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If you are interested in the deep debugging of HD-audio, read the
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HD-audio specification at first. The specification is found on
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Intel's web page, for example:
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- http://www.intel.com/standards/hdaudio/
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HD-AUDIO CONTROLLER
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-------------------
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DMA-Position Problem
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~~~~~~~~~~~~~~~~~~~~
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The most common problem of the controller is the inaccurate DMA
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pointer reporting. The DMA pointer for playback and capture can be
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read in two ways, either via a LPIB register or via a position-buffer
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map. As default the driver tries to read from the io-mapped
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position-buffer, and falls back to LPIB if the position-buffer appears
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dead. However, this detection isn't perfect on some devices. In such
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a case, you can change the default method via `position_fix` option.
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`position_fix=1` means to use LPIB method explicitly.
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`position_fix=2` means to use the position-buffer. 0 is the default
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value, the automatic check and fallback to LPIB as described in the
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above. If you get a problem of repeated sounds, this option might
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help.
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In addition to that, every controller is known to be broken regarding
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the wake-up timing. It wakes up a few samples before actually
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processing the data on the buffer. This caused a lot of problems, for
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example, with ALSA dmix or JACK. Since 2.6.27 kernel, the driver puts
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an artificial delay to the wake up timing. This delay is controlled
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via `bdl_pos_adj` option.
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When `bdl_pos_adj` is a negative value (as default), it's assigned to
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an appropriate value depending on the controller chip. For Intel
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chips, it'd be 1 while it'd be 32 for others. Usually this works.
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Only in case it doesn't work and you get warning messages, you should
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change this parameter to other values.
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Codec-Probing Problem
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~~~~~~~~~~~~~~~~~~~~~
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A less often but a more severe problem is the codec probing. When
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BIOS reports the available codec slots wrongly, the driver gets
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confused and tries to access the non-existing codec slot. This often
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results in the total screw-up, and destructs the further communication
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with the codec chips. The symptom appears usually as error messages
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like:
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------------------------------------------------------------------------
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hda_intel: azx_get_response timeout, switching to polling mode:
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last cmd=0x12345678
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hda_intel: azx_get_response timeout, switching to single_cmd mode:
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last cmd=0x12345678
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------------------------------------------------------------------------
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The first line is a warning, and this is usually relatively harmless.
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It means that the codec response isn't notified via an IRQ. The
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driver uses explicit polling method to read the response. It gives
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very slight CPU overhead, but you'd unlikely notice it.
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The second line is, however, a fatal error. If this happens, usually
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it means that something is really wrong. Most likely you are
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accessing a non-existing codec slot.
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Thus, if the second error message appears, try to narrow the probed
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codec slots via `probe_mask` option. It's a bitmask, and each bit
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corresponds to the codec slot. For example, to probe only the first
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slot, pass `probe_mask=1`. For the first and the third slots, pass
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`probe_mask=5` (where 5 = 1 | 4), and so on.
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Since 2.6.29 kernel, the driver has a more robust probing method, so
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this error might happen rarely, though.
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On a machine with a broken BIOS, sometimes you need to force the
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driver to probe the codec slots the hardware doesn't report for use.
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In such a case, turn the bit 8 (0x100) of `probe_mask` option on.
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Then the rest 8 bits are passed as the codec slots to probe
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unconditionally. For example, `probe_mask=0x103` will force to probe
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the codec slots 0 and 1 no matter what the hardware reports.
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Interrupt Handling
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~~~~~~~~~~~~~~~~~~
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In rare but some cases, the interrupt isn't properly handled as
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default. You would notice this by the DMA transfer error reported by
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ALSA PCM core, for example. Using MSI might help in such a case.
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Pass `enable_msi=1` option for enabling MSI.
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HD-AUDIO CODEC
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--------------
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Model Option
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~~~~~~~~~~~~
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The most common problem regarding the HD-audio driver is the
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unsupported codec features or the mismatched device configuration.
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Most of codec-specific code has several preset models, either to
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override the BIOS setup or to provide more comprehensive features.
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The driver checks PCI SSID and looks through the static configuration
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table until any matching entry is found. If you have a new machine,
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you may see a message like below:
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------------------------------------------------------------------------
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hda_codec: ALC880: BIOS auto-probing.
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------------------------------------------------------------------------
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Meanwhile, in the earlier versions, you would see a message like:
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------------------------------------------------------------------------
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hda_codec: Unknown model for ALC880, trying auto-probe from BIOS...
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------------------------------------------------------------------------
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Even if you see such a message, DON'T PANIC. Take a deep breath and
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keep your towel. First of all, it's an informational message, no
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warning, no error. This means that the PCI SSID of your device isn't
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listed in the known preset model (white-)list. But, this doesn't mean
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that the driver is broken. Many codec-drivers provide the automatic
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configuration mechanism based on the BIOS setup.
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The HD-audio codec has usually "pin" widgets, and BIOS sets the default
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configuration of each pin, which indicates the location, the
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connection type, the jack color, etc. The HD-audio driver can guess
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the right connection judging from these default configuration values.
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However -- some codec-support codes, such as patch_analog.c, don't
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support the automatic probing (yet as of 2.6.28). And, BIOS is often,
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yes, pretty often broken. It sets up wrong values and screws up the
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driver.
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The preset model is provided basically to overcome such a situation.
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When the matching preset model is found in the white-list, the driver
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assumes the static configuration of that preset and builds the mixer
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elements and PCM streams based on the static information. Thus, if
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you have a newer machine with a slightly different PCI SSID from the
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existing one, you may have a good chance to re-use the same model.
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You can pass the `model` option to specify the preset model instead of
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PCI SSID look-up.
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What `model` option values are available depends on the codec chip.
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Check your codec chip from the codec proc file (see "Codec Proc-File"
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section below). It will show the vendor/product name of your codec
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chip. Then, see Documentation/sound/alsa/HD-Audio-Models.txt file,
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the section of HD-audio driver. You can find a list of codecs
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and `model` options belonging to each codec. For example, for Realtek
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ALC262 codec chip, pass `model=ultra` for devices that are compatible
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with Samsung Q1 Ultra.
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Thus, the first thing you can do for any brand-new, unsupported and
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non-working HD-audio hardware is to check HD-audio codec and several
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different `model` option values. If you have any luck, some of them
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might suit with your device well.
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Some codecs such as ALC880 have a special model option `model=test`.
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This configures the driver to provide as many mixer controls as
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possible for every single pin feature except for the unsolicited
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events (and maybe some other specials). Adjust each mixer element and
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try the I/O in the way of trial-and-error until figuring out the whole
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I/O pin mappings.
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Note that `model=generic` has a special meaning. It means to use the
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generic parser regardless of the codec. Usually the codec-specific
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parser is much better than the generic parser (as now). Thus this
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option is more about the debugging purpose.
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Speaker and Headphone Output
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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One of the most frequent (and obvious) bugs with HD-audio is the
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silent output from either or both of a built-in speaker and a
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headphone jack. In general, you should try a headphone output at
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first. A speaker output often requires more additional controls like
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the external amplifier bits. Thus a headphone output has a slightly
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better chance.
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Before making a bug report, double-check whether the mixer is set up
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correctly. The recent version of snd-hda-intel driver provides mostly
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"Master" volume control as well as "Front" volume (where Front
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indicates the front-channels). In addition, there can be individual
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"Headphone" and "Speaker" controls.
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Ditto for the speaker output. There can be "External Amplifier"
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switch on some codecs. Turn on this if present.
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Another related problem is the automatic mute of speaker output by
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headphone plugging. This feature is implemented in most cases, but
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not on every preset model or codec-support code.
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In anyway, try a different model option if you have such a problem.
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Some other models may match better and give you more matching
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functionality. If none of the available models works, send a bug
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report. See the bug report section for details.
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If you are masochistic enough to debug the driver problem, note the
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following:
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- The speaker (and the headphone, too) output often requires the
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external amplifier. This can be set usually via EAPD verb or a
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certain GPIO. If the codec pin supports EAPD, you have a better
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chance via SET_EAPD_BTL verb (0x70c). On others, GPIO pin (mostly
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it's either GPIO0 or GPIO1) may turn on/off EAPD.
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- Some Realtek codecs require special vendor-specific coefficients to
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turn on the amplifier. See patch_realtek.c.
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- IDT codecs may have extra power-enable/disable controls on each
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analog pin. See patch_sigmatel.c.
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- Very rare but some devices don't accept the pin-detection verb until
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triggered. Issuing GET_PIN_SENSE verb (0xf09) may result in the
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codec-communication stall. Some examples are found in
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patch_realtek.c.
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Capture Problems
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~~~~~~~~~~~~~~~~
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The capture problems are often because of missing setups of mixers.
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Thus, before submitting a bug report, make sure that you set up the
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mixer correctly. For example, both "Capture Volume" and "Capture
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Switch" have to be set properly in addition to the right "Capture
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Source" or "Input Source" selection. Some devices have "Mic Boost"
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volume or switch.
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When the PCM device is opened via "default" PCM (without pulse-audio
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plugin), you'll likely have "Digital Capture Volume" control as well.
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This is provided for the extra gain/attenuation of the signal in
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software, especially for the inputs without the hardware volume
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control such as digital microphones. Unless really needed, this
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should be set to exactly 50%, corresponding to 0dB -- neither extra
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gain nor attenuation. When you use "hw" PCM, i.e., a raw access PCM,
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this control will have no influence, though.
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It's known that some codecs / devices have fairly bad analog circuits,
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and the recorded sound contains a certain DC-offset. This is no bug
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of the driver.
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Most of modern laptops have no analog CD-input connection. Thus, the
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recording from CD input won't work in many cases although the driver
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provides it as the capture source. Use CDDA instead.
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The automatic switching of the built-in and external mic per plugging
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is implemented on some codec models but not on every model. Partly
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because of my laziness but mostly lack of testers. Feel free to
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submit the improvement patch to the author.
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Direct Debugging
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~~~~~~~~~~~~~~~~
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If no model option gives you a better result, and you are a tough guy
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to fight against evil, try debugging via hitting the raw HD-audio
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codec verbs to the device. Some tools are available: hda-emu and
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hda-analyzer. The detailed description is found in the sections
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below. You'd need to enable hwdep for using these tools. See "Kernel
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Configuration" section.
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OTHER ISSUES
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------------
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Kernel Configuration
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~~~~~~~~~~~~~~~~~~~~
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In general, I recommend you to enable the sound debug option,
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`CONFIG_SND_DEBUG=y`, no matter whether you are debugging or not.
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This enables snd_printd() macro and others, and you'll get additional
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kernel messages at probing.
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In addition, you can enable `CONFIG_SND_DEBUG_VERBOSE=y`. But this
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will give you far more messages. Thus turn this on only when you are
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sure to want it.
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Don't forget to turn on the appropriate `CONFIG_SND_HDA_CODEC_*`
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options. Note that each of them corresponds to the codec chip, not
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the controller chip. Thus, even if lspci shows the Nvidia controller,
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you may need to choose the option for other vendors. If you are
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unsure, just select all yes.
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`CONFIG_SND_HDA_HWDEP` is a useful option for debugging the driver.
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When this is enabled, the driver creates hardware-dependent devices
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(one per each codec), and you have a raw access to the device via
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these device files. For example, `hwC0D2` will be created for the
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codec slot #2 of the first card (#0). For debug-tools such as
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hda-verb and hda-analyzer, the hwdep device has to be enabled.
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Thus, it'd be better to turn this on always.
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`CONFIG_SND_HDA_RECONFIG` is a new option, and this depends on the
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hwdep option above. When enabled, you'll have some sysfs files under
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the corresponding hwdep directory. See "HD-audio reconfiguration"
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section below.
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`CONFIG_SND_HDA_POWER_SAVE` option enables the power-saving feature.
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See "Power-saving" section below.
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Codec Proc-File
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~~~~~~~~~~~~~~~
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The codec proc-file is a treasure-chest for debugging HD-audio.
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It shows most of useful information of each codec widget.
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The proc file is located in /proc/asound/card*/codec#*, one file per
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each codec slot. You can know the codec vendor, product id and
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names, the type of each widget, capabilities and so on.
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This file, however, doesn't show the jack sensing state, so far. This
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is because the jack-sensing might be depending on the trigger state.
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This file will be picked up by the debug tools, and also it can be fed
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to the emulator as the primary codec information. See the debug tools
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section below.
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This proc file can be also used to check whether the generic parser is
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used. When the generic parser is used, the vendor/product ID name
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will appear as "Realtek ID 0262", instead of "Realtek ALC262".
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HD-Audio Reconfiguration
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~~~~~~~~~~~~~~~~~~~~~~~~
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This is an experimental feature to allow you re-configure the HD-audio
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codec dynamically without reloading the driver. The following sysfs
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files are available under each codec-hwdep device directory (e.g.
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/sys/class/sound/hwC0D0):
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vendor_id::
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Shows the 32bit codec vendor-id hex number. You can change the
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vendor-id value by writing to this file.
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subsystem_id::
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Shows the 32bit codec subsystem-id hex number. You can change the
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subsystem-id value by writing to this file.
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revision_id::
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Shows the 32bit codec revision-id hex number. You can change the
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revision-id value by writing to this file.
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afg::
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Shows the AFG ID. This is read-only.
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mfg::
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Shows the MFG ID. This is read-only.
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name::
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Shows the codec name string. Can be changed by writing to this
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file.
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modelname::
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Shows the currently set `model` option. Can be changed by writing
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to this file.
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init_verbs::
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The extra verbs to execute at initialization. You can add a verb by
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writing to this file. Pass three numbers: nid, verb and parameter
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(separated with a space).
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hints::
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Shows / stores hint strings for codec parsers for any use.
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Its format is `key = value`. For example, passing `hp_detect = yes`
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to IDT/STAC codec parser will result in the disablement of the
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headphone detection.
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init_pin_configs::
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Shows the initial pin default config values set by BIOS.
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driver_pin_configs::
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Shows the pin default values set by the codec parser explicitly.
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This doesn't show all pin values but only the changed values by
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the parser. That is, if the parser doesn't change the pin default
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config values by itself, this will contain nothing.
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user_pin_configs::
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Shows the pin default config values to override the BIOS setup.
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Writing this (with two numbers, NID and value) appends the new
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value. The given will be used instead of the initial BIOS value at
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the next reconfiguration time. Note that this config will override
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even the driver pin configs, too.
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reconfig::
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Triggers the codec re-configuration. When any value is written to
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this file, the driver re-initialize and parses the codec tree
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again. All the changes done by the sysfs entries above are taken
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into account.
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clear::
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Resets the codec, removes the mixer elements and PCM stuff of the
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specified codec, and clear all init verbs and hints.
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For example, when you want to change the pin default configuration
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value of the pin widget 0x14 to 0x9993013f, and let the driver
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re-configure based on that state, run like below:
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------------------------------------------------------------------------
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# echo 0x14 0x9993013f > /sys/class/sound/hwC0D0/user_pin_configs
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# echo 1 > /sys/class/sound/hwC0D0/reconfig
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------------------------------------------------------------------------
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Early Patching
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~~~~~~~~~~~~~~
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When CONFIG_SND_HDA_PATCH_LOADER=y is set, you can pass a "patch" as a
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firmware file for modifying the HD-audio setup before initializing the
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codec. This can work basically like the reconfiguration via sysfs in
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the above, but it does it before the first codec configuration.
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A patch file is a plain text file which looks like below:
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------------------------------------------------------------------------
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[codec]
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0x12345678 0xabcd1234 2
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[model]
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auto
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[pincfg]
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0x12 0x411111f0
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[verb]
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0x20 0x500 0x03
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0x20 0x400 0xff
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[hint]
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hp_detect = yes
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------------------------------------------------------------------------
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The file needs to have a line `[codec]`. The next line should contain
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three numbers indicating the codec vendor-id (0x12345678 in the
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example), the codec subsystem-id (0xabcd1234) and the address (2) of
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the codec. The rest patch entries are applied to this specified codec
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until another codec entry is given.
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The `[model]` line allows to change the model name of the each codec.
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In the example above, it will be changed to model=auto.
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Note that this overrides the module option.
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After the `[pincfg]` line, the contents are parsed as the initial
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default pin-configurations just like `user_pin_configs` sysfs above.
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The values can be shown in user_pin_configs sysfs file, too.
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Similarly, the lines after `[verb]` are parsed as `init_verbs`
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sysfs entries, and the lines after `[hint]` are parsed as `hints`
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sysfs entries, respectively.
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The hd-audio driver reads the file via request_firmware(). Thus,
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a patch file has to be located on the appropriate firmware path,
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typically, /lib/firmware. For example, when you pass the option
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`patch=hda-init.fw`, the file /lib/firmware/hda-init-fw must be
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present.
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The patch module option is specific to each card instance, and you
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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.
|
|
|
|
|
|
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-2.6.git
|
|
|
|
The master branch or for-next branches can be used as the main
|
|
development branches in general while the HD-audio specific patches
|
|
are committed in topic/hda branch.
|
|
|
|
If you are using the latest Linus tree, it'd be better to pull the
|
|
above GIT tree onto it. If you are using the older kernels, an easy
|
|
way to try the latest ALSA code is to build from the snapshot
|
|
tarball. There are daily tarballs and the latest snapshot tarball.
|
|
All can be built just like normal alsa-driver release packages, that
|
|
is, installed via the usual spells: configure, make and make
|
|
install(-modules). See INSTALL in the package. The snapshot tarballs
|
|
are found at:
|
|
|
|
- ftp://ftp.kernel.org/pub/linux/kernel/people/tiwai/snapshot/
|
|
|
|
|
|
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 followings:
|
|
|
|
kernel-bugzilla::
|
|
http://bugme.linux-foundation.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. You can fetch the latest version from:
|
|
|
|
- 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.
|
|
|
|
|
|
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 found in the ftp directory:
|
|
|
|
- ftp://ftp.kernel.org/pub/linux/kernel/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 is a part of alsa.git repository in
|
|
alsa-project.org:
|
|
|
|
- http://git.alsa-project.org/?p=alsa.git;a=tree;f=hda-analyzer
|
|
|
|
|
|
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 package is found in:
|
|
|
|
- ftp://ftp.kernel.org/pub/linux/kernel/people/tiwai/misc/
|
|
|
|
A git repository is available:
|
|
|
|
- git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/hda-emu.git
|
|
|
|
See README file in the tarball for more details about hda-emu
|
|
program.
|