October 2013 - Alsa-devel - mailman.alsa-project.org

[alsa-devel] [PATCH v3 0/5] ALSA: hda - hdmi: ATI/AMD multi-channel and HBR support
by Anssi Hannula 14 May '14

14 May '14

Hi all! Here's another revision of the ATI/AMD multichannel+HBR patchset. Changes: - added customizable callbacks instead of polluting generic code - fixed wrong codec id in rev3+ check (as previously noted) - cosmetics I've only tested this on NVIDIA/Intel, but I'd guess at least Peter should be able to test this on AMD in a few days or so. The earlier revisions were tested to fully work. Combined patch can be found at: http://onse.fi/files/atihdmi5.patch However, this patchset is on top recent sound-next commits so it does not directly apply on older kernels. Olivier, I hope you will be able to test this at some point as well (same things as last time), even though it will be a bit more work :) Anssi Hannula (5): ALSA: hda - hdmi: Allow HDA patches to customize more operations ALSA: hda - hdmi: Add ATI/AMD multi-channel audio support ALSA: hda - hdmi: Add ELD emulation for ATI/AMD codecs ALSA: hda - hdmi: Add HBR bitstreaming support for ATI/AMD HDMI codecs ALSA: hda - hdmi: Disable ramp-up/down for non-PCM on AMD codecs sound/pci/hda/hda_eld.c | 151 +++++++++++ sound/pci/hda/hda_local.h | 4 + sound/pci/hda/patch_hdmi.c | 643 +++++++++++++++++++++++++++++++++++++-------- 3 files changed, 689 insertions(+), 109 deletions(-) -- Anssi Hannula

9 70

[alsa-devel] Ambiguous DAPM widget names and DPCM
by Daniel Mack 21 Mar '14

21 Mar '14

Hi Mark, Hi Liam, I spent some hours reverse-engineering the DPCM code, and I plan to prepare a patch to add some documentation once I've assembled a fully working setup. However, I have a general question regarding DAPM widget names. DPCM uses DAPM widgets and routes in order to determine the FE <-> BE connections at runtime. The problem with this is that widget names are very ambiguous, as the automatically created widgets for DAIs are named after their stream_name properties, which contain "Playback" or "Capture" for all components in my case. Hence, the code which walks the connections (snd_soc_dapm_dai_get_connected_widgets()) will most likely match the wrong one (which has empty sound/sink lists), which results in a failure like this: [ 16.606268] fe: ASoC: fe no valid playback route I hacked the names of all components so they are unique, but even then, the problem is that snd_soc_dapm_new_dai_widgets() is called twice for the CPU DAI, once from soc_probe_platform(), and later from soc_probe_link_dais(), and both calls would create DAPM widgets with identical names, resulting in the same problem as described above. I don't know how to handle this, but I believe that nobody was really hit by this issue yet, as DPCM doesn't seem to be used widely, at least not by any machine code in mainline. One idea would be to change the automatically generated names of DAI widgets in order to make them unique, or re-factor the lookup routines. Any opinion on that? Do I miss a general consideration here? With more hacks in place, the setup somehow succeeds, but when the stream is opened, we'll hit a BUG() in sound/core/pcm_memory.c, because the FE device's DMA type is undefined. But that's another topic I'll address later. Thanks, Daniel

5 9

Re: [alsa-devel] snd-usb: "delay: estimated 0, actual 352"
by Takashi Iwai 08 Jan '14

08 Jan '14

At Thu, 6 Sep 2012 15:17:58 +0200, Markus Trippelsdorf wrote: > > On 2012.09.06 at 15:08 +0200, Takashi Iwai wrote: > > At Thu, 6 Sep 2012 11:43:48 +0200, > > Markus Trippelsdorf wrote: > > > > > > On 2012.09.06 at 10:21 +0200, Takashi Iwai wrote: > > > > At Thu, 06 Sep 2012 09:35:26 +0200, > > > > Takashi Iwai wrote: > > > > > > > > In short, a patch like below may fix the issue (note: completely > > > > untested!) > > > > > > No it doesn't, unfortunately... > > > > OK, I start tracking down the problem a bit more deeply now. > > > > The issue happens when the first two URBs are passed to > > retire_playback_urb(). These are URBs filled before start_endpoints() > > are set, so they contain actually zero size. Even though these are > > a sort of dummy packets, the driver still tries to check with the > > queued delay account, and gives bogus errors. > > > > So, essentially the messages are harmless and nothing to worry too > > much, but surely it doesn't look sexy. > > > > The patch below should fix the problem. Please give it a try. > > Yes, your patch finally fixes the problem. > Thank you Takashi-san. Thanks for your quick test! If Daniel has no objection with that patch, I'm going to merge it. Takashi

3 2

[alsa-devel] how to create alsa nodes?
by loody 12 Dec '13

12 Dec '13

Dear all: In destop x86 system, the udev will automatically create the nodes in snd directory, such as pcmC0D0c, pcmC0D1c, etc. I try to let the usb sound device work on mips platform, but I have no idea what is the proper way to create these nodes. Should I 1. create them one by one by hand from copying the attributes in my PC (if I have 2 or more usb sound devices, I have to first plug them in pc and monitor the nodes) 2. smarter way to do so? -- Regards, miloody

7 19

[alsa-devel] alsa/asoundlib.h file not found
by Appalayagari Sreedhar 05 Dec '13

05 Dec '13

Hi, I have integrated the codec driver and the kernel log shows the sound card is detected. now i want to test the codec. i tried the sample test code for capture and playback. i am getting a compilation errors due to the asoundlib.h. please find the error log for my application. main.c:2:23: error: asoundlib.h: No such file or directory main.c: In function 'main': main.c:7: error: 'snd_pcm_t' undeclared (first use in this function) main.c:7: error: (Each undeclared identifier is reported only once main.c:7: error: for each function it appears in.) main.c:7: error: 'pcm_handle' undeclared (first use in this function) main.c:10: error: 'snd_pcm_stream_t' undeclared (first use in this function) main.c:10: error: expected ';' before 'stream' main.c:15: error: 'snd_pcm_hw_params_t' undeclared (first use in this function) main.c:15: error: 'hwparams' undeclared (first use in this function) main.c:22: warning: 'return' with a value, in function returning void main.c:34: error: 'snd_pcm_uframes_t' undeclared (first use in this function) main.c:34: error: expected ';' before 'periodsize' main.c:46: error: 'SND_PCM_ACCESS_RW_INTERLEAVED' undeclared (first use in this function) main.c:48: warning: 'return' with a value, in function returning void main.c:52: error: 'SND_PCM_FORMAT_S16_LE' undeclared (first use in this function) main.c:54: warning: 'return' with a value, in function returning void main.c:62: warning: 'return' with a value, in function returning void main.c:65:19: warning: missing terminating " character main.c:65: error: missing terminating " character main.c:66: error: expected expression before '==' token main.c:66: error: stray '\' in program main.c:66:31: warning: missing terminating " character main.c:66: error: missing terminating " character main.c:67: error: expected ';' before '}' token main.c:72: warning: 'return' with a value, in function returning void main.c:78: warning: 'return' with a value, in function returning void main.c:86: error: 'periodsize' undeclared (first use in this function) main.c:88: warning: 'return' with a value, in function returning void main.c:99: warning: 'return' with a value, in function returning void main.c:112: warning: incompatible implicit declaration of built-in function 'malloc' main.c:115: error: 'num_frames' undeclared (first use in this function) main.c:5: warning: return type of 'main' is not 'int' please suggest what needs to be done to resolve this issue asap. Thank you, Sreedhar.

5 4

[alsa-devel] [PATCH v2 0/8] ARM: s3c64xx: Let amba-pl08x driver handle DMA
by Tomasz Figa 04 Dec '13

04 Dec '13

Since the patches extending support of amba-pl08x DMA engine driver to PL080S DMA engine (PL080 modified by Samsung) found in Samsung S3C64xx SoCs got merged into Linux 3.12, it is a good time to migrate the platform to use this driver and drop the legacy DMA code. Due to changes scattered across different areas of kernel, patches are based on merged 4 branches: - for-next of Kukjin Kim's Samsung tree, - clk-next of Mike Turquette's clock tree, - for-next of Mark Brown's SPI tree, - for-next of Mark Brown's ASoC tree. To ease testing I have prepared a branch in my private tree for anyone willing to check the patches out: git://github.com/tom3q/linux.git s3c64xx-pl08x-patches On S3C64xx-based Mini6410 and SMDK6410 boards, with I2S audio playback and capture (including full duplex operation) and also SPI using spidev: Tested-by: Tomasz Figa <tomasz.figa(a)gmail.com> Changes since v1: - Dropped the now merged patches adding PL080s support amba-pl08x driver, - Rebased onto current for-next branches of respective trees. - Stopped hijacking pl330_filter() symbol to plug pl08_filter_id() as channel filtering callback on S3C64xx. Changes since RFC v2: - Added clkdev lookups to old clock driver. - Added patches removing the old DMA driver and any remaining code needed by it. - Fixed DMA support for SPI. - Added a word about PL080S to amba-pl08x.c file header. - Changed definition of LLI words from enums to macros. - Extended debugging messages to handle PL080S variant as well. - Little cleanup of LLI dumping code. - Added check for peripheral flow control, which is unsupported by PL080S to dma_set_runtime_config. - Corrected transfer size mask of PL080S. Changes since RFC v1: - Returned to original way of storing quirks as booleans, as suggested by Russell, Linus and Arnd. - Added reg_config field to pl08x_phy_chan struct, which stores variant-specific address of channel config register, as suggested by Russell. - Simplified handling of extended maximum transfer size of PL080S (no more conditional passing of 0 as length to pl08x_cctl_bits()). - Reworked LLI handling in the driver to stop casting arbitrary memory to a struct and allow different word count of LLI entry, as suggested by Linus. - Removed AMBA ID override from S3C64xx PL080 initialization code. - Fixed brokenness of Samsung DMA wrapper API, which caused cyclic buffers to be queued multiple times when DMA engine is used. - Included patch adding clock aliases for DMA engines (depends on Common Clock Framework driver for S3C64xx). - Fixed several minor stylistic issues. Tomasz Figa (8): spi: s3c64xx: Do not require legacy DMA API in case of S3C64XX ASoC: Samsung: Do not require legacy DMA API in case of S3C64XX ARM: s3c64xx: Add support for DMA using generic amba-pl08x driver clk: samsung: s3c64xx: Add aliases for DMA clocks ARM: s3c64xx: Remove legacy DMA driver clk: samsung: s3c64xx: Remove clock aliases of old DMA driver spi: s3c64xx: Always select S3C64XX_PL080 when ARCH_S3C64XX is enabled ASoC: Samsung: Always select S3C64XX_PL080 when ARCH_S3C64XX is enabled arch/arm/Kconfig | 1 + arch/arm/mach-s3c64xx/Kconfig | 7 +- arch/arm/mach-s3c64xx/Makefile | 2 +- arch/arm/mach-s3c64xx/common.h | 5 + arch/arm/mach-s3c64xx/dma.c | 762 ------------------------------- arch/arm/mach-s3c64xx/include/mach/dma.h | 144 ++---- arch/arm/mach-s3c64xx/pl080.c | 244 ++++++++++ arch/arm/plat-samsung/devs.c | 10 +- arch/arm/plat-samsung/dma-ops.c | 8 +- drivers/clk/samsung/clk-s3c64xx.c | 4 +- drivers/spi/Kconfig | 2 +- sound/soc/samsung/Kconfig | 2 +- 12 files changed, 316 insertions(+), 875 deletions(-) delete mode 100644 arch/arm/mach-s3c64xx/dma.c create mode 100644 arch/arm/mach-s3c64xx/pl080.c -- 1.8.3.2

5 16

Re: [alsa-devel] [PATCH v2] ASoC: simple-card: add Device Tree support
by Mark Brown 03 Dec '13

03 Dec '13

On Thu, Oct 03, 2013 at 02:33:55AM -0700, Kuninori Morimoto wrote: > ping ? Don't send contentless pings. I'm waiting for review from the device tree guys but I see now that you didn't CC them so they're unlikely to respond - please resend CCing them.

4 31

[alsa-devel] [RFC 0/4] DT support for rx51-audio
by Sebastian Reichel 30 Nov '13

30 Nov '13

Hi, This patchset adds DT support in rx51-audio. I tested it on the Nokia N900 and was able to play sound with aplay using earphones and earspeaker. The Loudspeakers did not work. I don't know the reason. The patchset consists of 4 patches: 1. convert rx51-audio to snd_soc_register_card() 2. init audio in rx51 platform file 3. add some DT helpers to ASoC core 4. add DT support to rx51-audio Please note, that the patch is RFC level for now. For example non DT boot does not work, because I did not yet add pdata in boardcode. Proposed DTS node would look like this: sound: rx51-audio { compatible = "nokia,rx51-audio"; ti,mcbsp = <&mcbsp2>; ti,codec = <&tlv320aic3x>; ti,codec_aux = <&tlv320aic3x_aux>; ti,headset_amp = <&tpa6130a2>; tvout-selection-gpio = <&gpio2 8 GPIO_ACTIVE_HIGH>; /* 40 */ jack-detection-gpio = <&gpio6 17 GPIO_ACTIVE_HIGH>; /* 177 */ eci-sw-gpio = <&gpio6 22 GPIO_ACTIVE_HIGH>; /* 182 */ speaker-amp-gpio = <&twl_gpio 7 GPIO_ACTIVE_HIGH>; }; -- Sebastian Pali Rohár (2): ASoC: omap: rx51: Use snd_soc_register_card ARM: OMAP: rx51: Register audio device Sebastian Reichel (2): ASoC: Allow Aux Codecs to be specified using DT ASoC: RX-51: Add DT support to sound driver .../devicetree/bindings/sound/nokia,rx51.txt | 28 +++ .../devicetree/bindings/vendor-prefixes.txt | 1 + arch/arm/mach-omap2/board-rx51-peripherals.c | 11 ++ include/sound/rx51.h | 18 ++ include/sound/soc.h | 13 +- sound/soc/omap/omap-mcbsp.c | 5 +- sound/soc/omap/omap-mcbsp.h | 2 +- sound/soc/omap/rx51.c | 212 +++++++++++++++------ sound/soc/soc-core.c | 68 +++++-- 9 files changed, 277 insertions(+), 81 deletions(-) create mode 100644 Documentation/devicetree/bindings/sound/nokia,rx51.txt create mode 100644 include/sound/rx51.h -- 1.8.4.rc3

6 17

[alsa-devel] Audio Mini Conference Minutes - Edinburgh 21st October 2013
by Liam Girdwood 22 Nov '13

22 Nov '13

I've pasted below the minutes from this years ALSA developer mini conference in Edinburgh. I'll also add it to the developer Wiki alongside some slides from Eric and Tanu (once I know the correct answer to the anti-spam captcha). Fwiw, there are some interesting "unclaimed" tasks/projects below. Please feel free to volunteer for anything below that may interest you. Btw, if you are replying to start a thread about a certain subject below, please snip the other context and change the email to match the new $SUBJECT. This should make things easier to track. Thanks Liam Audio BOF - Monday October 21st 2013 - Edinburgh ================================================ Attendees :- ----------------------------------------------------------------------- Mark Brown, Liam Girdwood, Pierre Bossart, Patrick Lai, Lars-Peter Clausen, Eric Laurent, David Henningsson, Takashi Iwai, Colin Guthrie, Tanu Kaskinen, Arun Raghavan, Paul Handrigan, Daniel Mack, Dylan Reid, Sven Neuman, Dmimtris Papastamos, Charles Keepax, Nariman Poushin, João Paulo Rechi Vita, Alexander Patrakov, Micheal Wu, Lennart Poettering Topics ======= Pulseaudio route management and UCM ----------------------------------- There was interest for shared policy configuration file format across different systems. No such sharing has been planned. Tanu's initial reaction is that it's not feasible, but he is open to discussing it. What to do if there are multiple paths from A to B? One will be chosen, either arbitrarily or based on connection requirements or prioritization. How to control effect offloading? Tanu's vague idea is that if some kind of filtering is required/preferred, it's expressed as a requirement for a connection, and the node implementation will then enable the details of enabling the effect if such effect is available. Tanu doesn't know how well that would work in practice - and probably unaware of many details that would have to be taken into account. UCM being used by some people but missing good documentation. Liam to write documentation and use examples from Arun as "gold standard" example configurations. More UCM configs to go online in alsa-lib repo. UCM configs sometimes need updated for new kernel releases as Kcontrol strings have changed. Suggestions made for additional UUID for each kcontrol to lessen UCM config name changes (e.g. vendor-part-reg-shift-mask could be used as ASoC kcontrol UUID). Naming changes also effect HDA kcontrols, but no HDA UCM configs yet ? kcontrol UUID harder for DSP and HDA. Arun reported UCM issue with combination of devices. e.g. Enable dev 1 & 2 then disable dev 1 & 2. Maybe virtual device that combines devices ?? #include for UCM - should be easy to add. Simplifies config for family of similar devices like Panda, PandaES etc Device Names in UCM names. There are some standard names in UCM header but need more. Liam to add more names. Arbitration, UCM does not do arbitration but leaves that up to sound server. Controls names need more standardisation. Kcontrol naming mainly based on HW specified within data sheets. Difficult for userspace to cope with great degree of naming variations and provide enough information for userspace to know which volume is master etc. Audio Delay and Timing granularity ---------------------------------- Some DMA drivers very bad at providing position information used to work out buffer positions. Difficult for userspace to render audio and wake up correctly with such HW unless we can provide mechanism for userspace to know the DMA position accuracy. IOCTL suggested, info is in driver so easy to expose. There already is the SNDRV_PCM_INFO_BATCH flag which is supposed to indicated that the granularity is period-size-ish. It makes sense for applications like pulse-audio to check whether this flag is set or not. Hostless Audio -------------- Hostless should now use kcontrol to join the graph links to enable or disable and not hostless PCM device (old Android hack). e.g. FM playback loopback to codec, Modem PCM handling. i.e. CODEC <-> CODEC type. Need mixer to expose set config changes as link config is static e.g. WB/NB configs. Audio Offloading for Android ---------------------------- Avail in KK, supports > 1 compressed devices. No guarantee on no dropped samples when changing compressed to PCM and vice versa (or enabling effects ????) Not available yet when in use with video, no tech reason to stop this. AV sync good. Some effects can be offloaded and some not. Compressed API -------------- Intel to upstream remaining fixes. AR - Liam, Vinod. Stable updates with no users. 3.10 is stable but we can changes core API since there are no users. Android Audio Effects Framework Modifications --------------------------------------------- Composite with HW and SW representations. Supports 3rd party GUI controls but they must use the effect API and not bypass with private IOCTLs. How do we do library, like tiny effects ? API exists in use by Factory, can we extend to alsa ? Nobody using compressed and effects outside of Android atm. 24 Bit HiRes Audio for Android ------------------------------ How do we handle 24 bit audio at fast rates e.g. 192kHz. Being pushed by market. Flac suggested as source media and not PCM. We could use offload, on roadmap for Hires audio on android PCM, maybe float instead of 24 bit. Need for 192kHz, Probably not use effects. Effect Support in ALSA ---------------------- Several proposals for APIs. Control device type, do we need new control or use existing CTL ? Per card or per DSP / CODEC. ? Not to use control API for everything , could confuse some userspace. Get/set could be any control type, not just binary ? Binary blobs used to hide workings of effects. Topology Query and edit - query the graph from HDA/DAPM - used to establish connections and end points. per card based IOCTL. Could be new alsamixer to allow users to control volumes. Media controller API. How do we match to ALSA. Need non LGPL library for android. Missing certain features, someone needs to write code. MC API is Video oriented, library is just wrappers around IOCTLs, 1 man week of simple work to implement non LGPL version. Removal/creation - kernel can provide any type of information to user space key values. Document new keys, generic structure. Channel mapping possible using tuples. Need to support dynamic entity information. Handles static pipeline well, and can also expose dynamic with some complexity (with more entities). Abstract away sink+sources in userspace library, maybe too complex. Trivial to use UUIDs for dynamic entities. Start with prototype and see what happens. Action on Intel/Vinod ? Topology 2 NODES and EFFECT IOCTLS could be replaced with media controller as MediaC provides good match. Sending/Receiving Binary data to drivers ---------------------------------------- Use cases that go above 256/512 ? byte limit for binary controls. Extend for larger ? Do something about it. Action for ????? Tiwai/Mark ???? MMAP for some parameters. Visualizer, peak meters. ? Multiple of 4k pages. Can be used for DMA buffer positions on IPC IRQ based DSPs. Avoid copying large amounts of data. trade off for DSP. Usable for DEBUG too. Prototype and see what happens - Who ?? Expose API for sending large chunks of data e.g. 2MB. Nice for generic code to send this data (no special tooling) Needs new API for large data chunks. What about write(). Patrick to prototype some code. DSP resource management ----------------------- Do we need pre-trigger to work out MIPS/MHz + buffer resources for DSP resources. Tables used atm for most DSPs. Something for policy or UCM to specify ? Could change for different FWs. Peak and average loading gives difficulty. Might not get feedback, latency in the pipe and need to agree on units of measurements. Complex problem. Estimate worst case. OMAP4 example uses DAPM, expose reource usage numbers, expose capability limits. Liam to publish clock resource management logic for Haswell DSP. Can be used as starting point for investigations into feasibility etc. HDMI - Hotplug -------------- Can cause changes to audio path. Do we need to tell userspace card has changed ? Specific for ELD or generic problem ? Suggestion to remove and then insert card not usable Signal for monitor re-pluging, ELD not available right away. How to sync ELD information, ELD time out signal ? DSPs can change capabilities, ELDS can be garbage. PA maybe ask to quickly for ELD info, expose new jack for HDA when ELD is known. Generic event to tell userspace that card has changed. HDA/MIMI specific solution. Generic API to talk between audio and DRM devices. Bespoke atm. Code lives in the wrong place atm. Need to sync. Code is already upstream. David to prototype a solution based on deferring the probe until ELD is ready. Mic/LED hotkey -------------- Few different scenarios - from slides. Multiple cards and multiple mics. Which Mic will LED represent ? card or system or other. We'll not use the LED class because it does not buy us anything: LED class is writable for root only, and PA does not run as root. Nobody seemed to have a firm convincing argument in any direction. As such, keeping the current behaviour (reflect mute state of internal card) will be kept for now. Alexander suggested looking at what NetworkManager does with the wifi-off indicator in the presence of multiple wireless devices with (potentially) their own wifi-off switches. Performance - Use case startup ------------------------------ Discussing optimisation from DPCM - users QC, TI and Intel. DSP can route to multiple endpoints from a single PCM. Startup call back -> PCM -> FE -> BE. Then hw_params(), followed by prepare() and trigger(). Cold start latency 113ms on QDSP since some slow ops on QDSP are serialised. Solution to shift some prepare() work into DAPM. DAPM ops are tun in parallel and a workq. Compressed offload ------------------ Video/Audio offload - pass audio timestamp. Metadata for QDSP stored at front of compressed data by QC. Transport stream already supported by compressed API. Timestamps may differ in DSP implementations. AV sync topic requested by V4Linux for long time. Only discussed for PCM not offload, need TS for offload and support of V4Linux guys. Compressed offload transcoding. - How do we specify this transform. New API for userspace to spec output of decoder. All sorts of routing combinations are possible making implementation very difficult. Query the the BE connected to the FE, we may be able to call existing PCM API's on the BE PCM. Patrick to prototype some code. Firmware based Kcontrols and Graphs ----------------------------------- Patches have been developed to attach Kcontrol and Graph meta data to DSP FW. This allows single DSP driver to be used with multiple FWs without modification. Patch V1 reviewed last year before TI layoff and we should be ready for V2 before end of year. Consists of kernel patch and userspace tool to generate the control and graph data. Current userspace tool is needing work to improve config generation. There is no config file format at present. Paul and some Wolfson guys have volunteered to assist in this effort. Code currently works on OMAP4 platforms. Kernel code is here (top 5 patches) :- https://git.kernel.org/cgit/linux/kernel/git/lrg/asoc.git/log/?h=topic/firm… Userspace tool is here :- git@gitorious.org:omap-audio/asoc-fw.git Clean up ALSA code ------------------ Move plugins to their projects - move ffmpeg plugin to ffmpeg project, etc. Drivers, requests to move to device probe model, away from alsa model. Need to register device files at end of driver creation. Input susbsys uses possible method that could be copied. sysfs files need sync to avoid races for creation. Agreement. Process, How do we work ----------------------- Bug reports. Who looks at bugs. No takers. New mailing lists ? no, just use filters to hide emails that are not of interest. Misc ---- Softvol, add SND_CTL for no softvol in ctl open. Use alsa conf file or ctl. Arun encouraged to revive the email thread on the topic. Possible bug where specially crafted javascript can set PA volume to 100%. Defined pulseaudio behviour (Colin), related to flat volumes. New ASoC drivers must now use generic DMA engine PCM driver. Non atomic trigger requirments from DSP drivers. DSPs mostly sleep when performing IPC and need a trigger call that can sleep. Patrick will investigate. Propagate errors from BEs to FEs. Patrick to investigate. This will also include reporting underruns too. System restart for DSP FW crashes. This requires reloading all FW and trying to recover all active streams. Patrick to investigate. Lennart asked about the support of audio "mute" via systemd session management, like input and drm drivers already do. Takashi took a look at input evdev code, and actually it's revoking instead of muting. The advantage of revoking over muting is that it's simpler and doesn't need the capability check, as far as he read through discussion threads. But Takashi is not sure whether revoking behavior is good for PA at all.

4 6

[alsa-devel] [RFC 0/2] I2C and SPI dev_name change for ACPI enumerated slaves
by Jarkko Nikula 16 Nov '13

16 Nov '13

Hi We've run into problem of changing I2C device names while developing ALSA SoC drivers for x86 based systems. Changing device names makes more difficult to match devices by their name. Which is what we use within ASoC subsystem. These changing names comes from changing adapter/bus numbering which could occur due variable amount of bus controllers, probe order, add-on cards or different BIOS settings. Patches here try to solve the problem on ACPI 5 based systems by using stable ACPI device name with a "i2c-"/"spi-" prefix for I2C/SPI slave device names. Both patches are independent from each other and can go through their own subsystems. Jarkko Nikula (2): i2c: Use stable dev_name for ACPI enumerated I2C slaves spi: Use stable dev_name for ACPI enumerated SPI slaves drivers/i2c/i2c-core.c | 24 ++++++++++++++++++++---- drivers/spi/spi.c | 21 ++++++++++++++++++--- 2 files changed, 38 insertions(+), 7 deletions(-) -- 1.8.4.rc3

5 41