diff options
Diffstat (limited to 'Documentation/sound')
| -rw-r--r-- | Documentation/sound/alsa/ALSA-Configuration.txt | 10 | ||||
| -rw-r--r-- | Documentation/sound/alsa/HD-Audio-Models.txt | 94 | ||||
| -rw-r--r-- | Documentation/sound/alsa/HD-Audio.txt | 7 | ||||
| -rw-r--r-- | Documentation/sound/alsa/compress_offload.txt | 188 |
4 files changed, 205 insertions, 94 deletions
diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt index 936699e4f04b..6f75ba3b8a39 100644 --- a/Documentation/sound/alsa/ALSA-Configuration.txt +++ b/Documentation/sound/alsa/ALSA-Configuration.txt @@ -860,7 +860,8 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed. [Multiple options for each card instance] model - force the model name - position_fix - Fix DMA pointer (0 = auto, 1 = use LPIB, 2 = POSBUF) + position_fix - Fix DMA pointer (0 = auto, 1 = use LPIB, 2 = POSBUF, + 3 = VIACOMBO, 4 = COMBO) probe_mask - Bitmask to probe codecs (default = -1, meaning all slots) When the bit 8 (0x100) is set, the lower 8 bits are used as the "fixed" codec slots; i.e. the driver probes the @@ -925,6 +926,11 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed. (Usually SD_LPIB register is more accurate than the position buffer.) + position_fix=3 is specific to VIA devices. The position + of the capture stream is checked from both LPIB and POSBUF + values. position_fix=4 is a combination mode, using LPIB + for playback and POSBUF for capture. + NB: If you get many "azx_get_response timeout" messages at loading, it's likely a problem of interrupts (e.g. ACPI irq routing). Try to boot with options like "pci=noacpi". Also, you @@ -1588,7 +1594,7 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed. Module supports autoprobe a chip. - Note: the driver may have problems regarding endianess. + Note: the driver may have problems regarding endianness. The power-management is supported. diff --git a/Documentation/sound/alsa/HD-Audio-Models.txt b/Documentation/sound/alsa/HD-Audio-Models.txt index edad99abec21..d97d992ced14 100644 --- a/Documentation/sound/alsa/HD-Audio-Models.txt +++ b/Documentation/sound/alsa/HD-Audio-Models.txt @@ -8,53 +8,14 @@ ALC880 5stack-digout 5-jack in back, 2-jack in front, a SPDIF out 6stack 6-jack in back, 2-jack in front 6stack-digout 6-jack with a SPDIF out - w810 3-jack - z71v 3-jack (HP shared SPDIF) - asus 3-jack (ASUS Mobo) - asus-w1v ASUS W1V - asus-dig ASUS with SPDIF out - asus-dig2 ASUS with SPDIF out (using GPIO2) - uniwill 3-jack - fujitsu Fujitsu Laptops (Pi1536) - F1734 2-jack - lg LG laptop (m1 express dual) - lg-lw LG LW20/LW25 laptop - tcl TCL S700 - clevo Clevo laptops (m520G, m665n) - medion Medion Rim 2150 - test for testing/debugging purpose, almost all controls can be - adjusted. Appearing only when compiled with - $CONFIG_SND_DEBUG=y - auto auto-config reading BIOS (default) ALC260 ====== - fujitsu Fujitsu S7020 - acer Acer TravelMate - will Will laptops (PB V7900) - replacer Replacer 672V - favorit100 Maxdata Favorit 100XS - basic fixed pin assignment (old default model) - test for testing/debugging purpose, almost all controls can - adjusted. Appearing only when compiled with - $CONFIG_SND_DEBUG=y - auto auto-config reading BIOS (default) + N/A ALC262 ====== - fujitsu Fujitsu Laptop - benq Benq ED8 - benq-t31 Benq T31 - hippo Hippo (ATI) with jack detection, Sony UX-90s - hippo_1 Hippo (Benq) with jack detection - toshiba-s06 Toshiba S06 - toshiba-rx1 Toshiba RX1 - tyan Tyan Thunder n6650W (S2915-E) - ultra Samsung Q1 Ultra Vista model - lenovo-3000 Lenovo 3000 y410 - nec NEC Versa S9100 - basic fixed pin assignment w/o SPDIF - auto auto-config reading BIOS (default) + N/A ALC267/268 ========== @@ -82,55 +43,7 @@ ALC680 ALC882/883/885/888/889 ====================== - 3stack-dig 3-jack with SPDIF I/O - 6stack-dig 6-jack digital with SPDIF I/O - arima Arima W820Di1 - targa Targa T8, MSI-1049 T8 - asus-a7j ASUS A7J - asus-a7m ASUS A7M - macpro MacPro support - mb5 Macbook 5,1 - macmini3 Macmini 3,1 - mba21 Macbook Air 2,1 - mbp3 Macbook Pro rev3 - imac24 iMac 24'' with jack detection - imac91 iMac 9,1 - w2jc ASUS W2JC - 3stack-2ch-dig 3-jack with SPDIF I/O (ALC883) - alc883-6stack-dig 6-jack digital with SPDIF I/O (ALC883) - 3stack-6ch 3-jack 6-channel - 3stack-6ch-dig 3-jack 6-channel with SPDIF I/O - 6stack-dig-demo 6-jack digital for Intel demo board - acer Acer laptops (Travelmate 3012WTMi, Aspire 5600, etc) - acer-aspire Acer Aspire 9810 - acer-aspire-4930g Acer Aspire 4930G - acer-aspire-6530g Acer Aspire 6530G - acer-aspire-7730g Acer Aspire 7730G - acer-aspire-8930g Acer Aspire 8930G - medion Medion Laptops - targa-dig Targa/MSI - targa-2ch-dig Targa/MSI with 2-channel - targa-8ch-dig Targa/MSI with 8-channel (MSI GX620) - laptop-eapd 3-jack with SPDIF I/O and EAPD (Clevo M540JE, M550JE) - lenovo-101e Lenovo 101E - lenovo-nb0763 Lenovo NB0763 - lenovo-ms7195-dig Lenovo MS7195 - lenovo-sky Lenovo Sky - haier-w66 Haier W66 - 3stack-hp HP machines with 3stack (Lucknow, Samba boards) - 6stack-dell Dell machines with 6stack (Inspiron 530) - mitac Mitac 8252D - clevo-m540r Clevo M540R (6ch + digital) - clevo-m720 Clevo M720 laptop series - fujitsu-pi2515 Fujitsu AMILO Pi2515 - fujitsu-xa3530 Fujitsu AMILO XA3530 - 3stack-6ch-intel Intel DG33* boards - intel-alc889a Intel IbexPeak with ALC889A - intel-x58 Intel DX58 with ALC889 - asus-p5q ASUS P5Q-EM boards - mb31 MacBook 3,1 - sony-vaio-tt Sony VAIO TT - auto auto-config reading BIOS (default) + N/A ALC861/660 ========== @@ -350,7 +263,6 @@ STAC92HD83* mic-ref Reference board with power management for ports dell-s14 Dell laptop dell-vostro-3500 Dell Vostro 3500 laptop - hp HP laptops with (inverted) mute-LED hp-dv7-4000 HP dv-7 4000 auto BIOS setup (default) diff --git a/Documentation/sound/alsa/HD-Audio.txt b/Documentation/sound/alsa/HD-Audio.txt index 91fee3b45fb8..7813c06a5c71 100644 --- a/Documentation/sound/alsa/HD-Audio.txt +++ b/Documentation/sound/alsa/HD-Audio.txt @@ -59,7 +59,12 @@ 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 and ATI controllers. 0 is the default value for all other +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. diff --git a/Documentation/sound/alsa/compress_offload.txt b/Documentation/sound/alsa/compress_offload.txt new file mode 100644 index 000000000000..c83a835350f0 --- /dev/null +++ b/Documentation/sound/alsa/compress_offload.txt @@ -0,0 +1,188 @@ + compress_offload.txt + ===================== + Pierre-Louis.Bossart <pierre-louis.bossart@linux.intel.com> + Vinod Koul <vinod.koul@linux.intel.com> + +Overview + +Since its early days, the ALSA API was defined with PCM support or +constant bitrates payloads such as IEC61937 in mind. Arguments and +returned values in frames are the norm, making it a challenge to +extend the existing API to compressed data streams. + +In recent years, audio digital signal processors (DSP) were integrated +in system-on-chip designs, and DSPs are also integrated in audio +codecs. Processing compressed data on such DSPs results in a dramatic +reduction of power consumption compared to host-based +processing. Support for such hardware has not been very good in Linux, +mostly because of a lack of a generic API available in the mainline +kernel. + +Rather than requiring a compability break with an API change of the +ALSA PCM interface, a new 'Compressed Data' API is introduced to +provide a control and data-streaming interface for audio DSPs. + +The design of this API was inspired by the 2-year experience with the +Intel Moorestown SOC, with many corrections required to upstream the +API in the mainline kernel instead of the staging tree and make it +usable by others. + +Requirements + +The main requirements are: + +- separation between byte counts and time. Compressed formats may have + a header per file, per frame, or no header at all. The payload size + may vary from frame-to-frame. As a result, it is not possible to + estimate reliably the duration of audio buffers when handling + compressed data. Dedicated mechanisms are required to allow for + reliable audio-video synchronization, which requires precise + reporting of the number of samples rendered at any given time. + +- Handling of multiple formats. PCM data only requires a specification + of the sampling rate, number of channels and bits per sample. In + contrast, compressed data comes in a variety of formats. Audio DSPs + may also provide support for a limited number of audio encoders and + decoders embedded in firmware, or may support more choices through + dynamic download of libraries. + +- Focus on main formats. This API provides support for the most + popular formats used for audio and video capture and playback. It is + likely that as audio compression technology advances, new formats + will be added. + +- Handling of multiple configurations. Even for a given format like + AAC, some implementations may support AAC multichannel but HE-AAC + stereo. Likewise WMA10 level M3 may require too much memory and cpu + cycles. The new API needs to provide a generic way of listing these + formats. + +- Rendering/Grabbing only. This API does not provide any means of + hardware acceleration, where PCM samples are provided back to + user-space for additional processing. This API focuses instead on + streaming compressed data to a DSP, with the assumption that the + decoded samples are routed to a physical output or logical back-end. + + - Complexity hiding. Existing user-space multimedia frameworks all + have existing enums/structures for each compressed format. This new + API assumes the existence of a platform-specific compatibility layer + to expose, translate and make use of the capabilities of the audio + DSP, eg. Android HAL or PulseAudio sinks. By construction, regular + applications are not supposed to make use of this API. + + +Design + +The new API shares a number of concepts with with the PCM API for flow +control. Start, pause, resume, drain and stop commands have the same +semantics no matter what the content is. + +The concept of memory ring buffer divided in a set of fragments is +borrowed from the ALSA PCM API. However, only sizes in bytes can be +specified. + +Seeks/trick modes are assumed to be handled by the host. + +The notion of rewinds/forwards is not supported. Data committed to the +ring buffer cannot be invalidated, except when dropping all buffers. + +The Compressed Data API does not make any assumptions on how the data +is transmitted to the audio DSP. DMA transfers from main memory to an +embedded audio cluster or to a SPI interface for external DSPs are +possible. As in the ALSA PCM case, a core set of routines is exposed; +each driver implementer will have to write support for a set of +mandatory routines and possibly make use of optional ones. + +The main additions are + +- get_caps +This routine returns the list of audio formats supported. Querying the +codecs on a capture stream will return encoders, decoders will be +listed for playback streams. + +- get_codec_caps For each codec, this routine returns a list of +capabilities. The intent is to make sure all the capabilities +correspond to valid settings, and to minimize the risks of +configuration failures. For example, for a complex codec such as AAC, +the number of channels supported may depend on a specific profile. If +the capabilities were exposed with a single descriptor, it may happen +that a specific combination of profiles/channels/formats may not be +supported. Likewise, embedded DSPs have limited memory and cpu cycles, +it is likely that some implementations make the list of capabilities +dynamic and dependent on existing workloads. In addition to codec +settings, this routine returns the minimum buffer size handled by the +implementation. This information can be a function of the DMA buffer +sizes, the number of bytes required to synchronize, etc, and can be +used by userspace to define how much needs to be written in the ring +buffer before playback can start. + +- set_params +This routine sets the configuration chosen for a specific codec. The +most important field in the parameters is the codec type; in most +cases decoders will ignore other fields, while encoders will strictly +comply to the settings + +- get_params +This routines returns the actual settings used by the DSP. Changes to +the settings should remain the exception. + +- get_timestamp +The timestamp becomes a multiple field structure. It lists the number +of bytes transferred, the number of samples processed and the number +of samples rendered/grabbed. All these values can be used to determine +the avarage bitrate, figure out if the ring buffer needs to be +refilled or the delay due to decoding/encoding/io on the DSP. + +Note that the list of codecs/profiles/modes was derived from the +OpenMAX AL specification instead of reinventing the wheel. +Modifications include: +- Addition of FLAC and IEC formats +- Merge of encoder/decoder capabilities +- Profiles/modes listed as bitmasks to make descriptors more compact +- Addition of set_params for decoders (missing in OpenMAX AL) +- Addition of AMR/AMR-WB encoding modes (missing in OpenMAX AL) +- Addition of format information for WMA +- Addition of encoding options when required (derived from OpenMAX IL) +- Addition of rateControlSupported (missing in OpenMAX AL) + +Not supported: + +- Support for VoIP/circuit-switched calls is not the target of this + API. Support for dynamic bit-rate changes would require a tight + coupling between the DSP and the host stack, limiting power savings. + +- Packet-loss concealment is not supported. This would require an + additional interface to let the decoder synthesize data when frames + are lost during transmission. This may be added in the future. + +- Volume control/routing is not handled by this API. Devices exposing a + compressed data interface will be considered as regular ALSA devices; + volume changes and routing information will be provided with regular + ALSA kcontrols. + +- Embedded audio effects. Such effects should be enabled in the same + manner, no matter if the input was PCM or compressed. + +- multichannel IEC encoding. Unclear if this is required. + +- Encoding/decoding acceleration is not supported as mentioned + above. It is possible to route the output of a decoder to a capture + stream, or even implement transcoding capabilities. This routing + would be enabled with ALSA kcontrols. + +- Audio policy/resource management. This API does not provide any + hooks to query the utilization of the audio DSP, nor any premption + mechanisms. + +- No notion of underun/overrun. Since the bytes written are compressed + in nature and data written/read doesn't translate directly to + rendered output in time, this does not deal with underrun/overun and + maybe dealt in user-library + +Credits: +- Mark Brown and Liam Girdwood for discussions on the need for this API +- Harsha Priya for her work on intel_sst compressed API +- Rakesh Ughreja for valuable feedback +- Sing Nallasellan, Sikkandar Madar and Prasanna Samaga for + demonstrating and quantifying the benefits of audio offload on a + real platform. |
