October 2018 - Alsa-devel - mailman.alsa-project.org

[alsa-devel] [PATCH 0/2] Introduce dmic mode switch delay parameter
by Jenny TC 25 Oct '18

25 Oct '18

Some DMICs need clock to be running for a specified duration as per the DMIC spec to complete the mode transition like sleep to mormal, off to normal etc. Jenny TC (2): ASoC: dmic: Enable ACPI device entry ASoC: dmic: Introduce mode switch delay sound/soc/codecs/dmic.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) -- 1.9.1

6 11

[alsa-devel] [PATCH] alsa-utils: fix identation indentation on speaker-test.c
by Eduardo Abinader 25 Oct '18

25 Oct '18

Signed-off-by: Eduardo Abinader <eduardoabinader(a)gmail.com> --- speaker-test/speaker-test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/speaker-test/speaker-test.c b/speaker-test/speaker-test.c index 773af0a..4aac30c 100644 --- a/speaker-test/speaker-test.c +++ b/speaker-test/speaker-test.c @@ -1207,7 +1207,7 @@ int main(int argc, char *argv[]) { gettimeofday(&tv1, NULL); for(chn = 0; chn < channels; chn++) { - int channel = get_speaker_channel(chn); + int channel = get_speaker_channel(chn); printf(" %d - %s\n", channel, get_channel_name(channel)); err = write_loop(handle, channel, ((rate*3)/period_size), frames); -- 2.17.1

2 1

[alsa-devel] [PATCH v2 - AAF PCM plugin 0/7] Introduce AVTP Audio Format (AAF) plugin
by Andre Guedes 25 Oct '18

25 Oct '18

Hi all, This new version addresses the feedback from v1 and fixes a bug on capture mode. Code-wise, the changes are very trivial, no major diffs. Below follows the highlights: * Standard headers like linux/if_ether.h are now checked by configure script. * The 'static' modifier was added to array variables in aaf_hw_constraint(). * aaf_close() callback was simplified. * aaf_rx_pdu() was modified so it doesn't return an error in case the number of bytes read by recv() is different from aaf->pdu_size. This is an expected situation and it means the received AVTPDU doesn't belong to the AAF stream the plugin is interested in so it should simply drop that AVTPDU. This fixes a bug when running multiple streams (with different AVPTU sizes) concurrently. Additionally, this new version improves the instructions in doc/aaf.txt in order to make it easier to test the plugin. Anyone should be able to test it just by copying and pasting the instructions. To recap what has been discussed about the plugin so far, check the comments in RFC and PATCH series archive [1-3]. All versions of this series can be also found in my alsa-plugins tree in github [4]. Regards, Andre [1] http://mailman.alsa-project.org/pipermail/alsa-devel/2018-August/139494.html [2] http://mailman.alsa-project.org/pipermail/alsa-devel/2018-September/140290.… [3] http://mailman.alsa-project.org/pipermail/alsa-devel/2018-October/140667.ht… [4] https://github.com/aguedes/alsa-plugins Andre Guedes (7): aaf: Introduce plugin skeleton aaf: Load configuration parameters aaf: Implement Playback mode support aaf: Prepare for Capture mode support aaf: Implement Capture mode support aaf: Implement dump() ioplug callback aaf: Add support for direct read/write transfers Makefile.am | 3 + aaf/Makefile.am | 9 + aaf/pcm_aaf.c | 1200 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ configure.ac | 11 + doc/aaf.txt | 157 ++++++++ 5 files changed, 1380 insertions(+) create mode 100644 aaf/Makefile.am create mode 100644 aaf/pcm_aaf.c create mode 100644 doc/aaf.txt -- 2.14.4

3 11

[alsa-devel] KASAN: use-after-free Read in snd_seq_timer_interrupt
by syzbot 24 Oct '18

24 Oct '18

Hello, syzbot found the following crash on: HEAD commit: 44786880df19 Merge branch 'parisc-4.20-1' of git://git.ker.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=178c8bad400000 kernel config: https://syzkaller.appspot.com/x/.config?x=5071a2e3cb82c943 dashboard link: https://syzkaller.appspot.com/bug?extid=d5136d4d3240cbe45a2a compiler: gcc (GCC) 8.0.1 20180413 (experimental) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+d5136d4d3240cbe45a2a(a)syzkaller.appspotmail.com ================================================================== BUG: KASAN: use-after-free in snd_seq_timer_interrupt+0x364/0x3e0 sound/core/seq/seq_timer.c:145 Read of size 8 at addr ffff8801cf71c118 by task syz-executor0/24085 CPU: 1 PID: 24085 Comm: syz-executor0 Not tainted 4.19.0+ #300 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x244/0x39d lib/dump_stack.c:113 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 snd_seq_timer_interrupt+0x364/0x3e0 sound/core/seq/seq_timer.c:145 snd_timer_interrupt+0x9ff/0x1660 sound/core/timer.c:855 snd_timer_s_function+0xcd/0x130 sound/core/timer.c:1094 call_timer_fn+0x272/0x920 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers+0x7e5/0xc70 kernel/time/timer.c:1682 run_timer_softirq+0x52/0xb0 kernel/time/timer.c:1695 __do_softirq+0x308/0xb7e kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1cb/0x760 arch/x86/kernel/apic/apic.c:1061 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:801 </IRQ> RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:761 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xaf/0xd0 kernel/locking/spinlock.c:184 Code: 30 f6 31 89 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 28 48 83 3d 28 cd 7c 01 00 74 15 48 89 df 57 9d <0f> 1f 44 00 00 eb ad e8 7c 52 4b f9 eb bb 0f 0b 0f 0b e8 8a 54 0e RSP: 0018:ffff880181eaf508 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: 0000000000000282 RCX: 0000000000000000 RDX: 1ffffffff1263ec6 RSI: 0000000000000001 RDI: 0000000000000282 RBP: ffff880181eaf518 R08: ffff88018378a140 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801c0b94ac0 R13: ffff8801c0b94300 R14: ffff8801daf2cc40 R15: 0000000000000001 try_to_wake_up+0x10a/0x12e0 kernel/sched/core.c:2056 wake_up_process kernel/sched/core.c:2124 [inline] wake_up_q+0xa4/0x100 kernel/sched/core.c:440 futex_wake+0x61f/0x760 kernel/futex.c:1556 do_futex+0x2e4/0x26d0 kernel/futex.c:3533 __do_sys_futex kernel/futex.c:3589 [inline] __se_sys_futex kernel/futex.c:3557 [inline] __x64_sys_futex+0x472/0x6a0 kernel/futex.c:3557 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:0000000000a3fbf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000000072bfa0 RCX: 0000000000457569 RDX: 0000000000000000 RSI: 0000000000000081 RDI: 000000000072bfa8 RBP: 00000000000003b7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000a3fcb0 R11: 0000000000000246 R12: 000000000072bfac R13: 000000000072bfac R14: 0000000000000003 R15: 0000000000000001 Allocated by task 24073: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kmem_cache_alloc_trace+0x152/0x750 mm/slab.c:3620 kmalloc include/linux/slab.h:513 [inline] kzalloc include/linux/slab.h:707 [inline] queue_new sound/core/seq/seq_queue.c:113 [inline] snd_seq_queue_alloc+0xab/0x5b0 sound/core/seq/seq_queue.c:185 snd_seq_ioctl_create_queue+0xb0/0x320 sound/core/seq/seq_clientmgr.c:1522 snd_seq_ioctl+0x253/0x440 sound/core/seq/seq_clientmgr.c:2138 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 24072: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3813 queue_delete+0x90/0xb0 sound/core/seq/seq_queue.c:156 snd_seq_queue_client_leave+0x36/0x170 sound/core/seq/seq_queue.c:584 seq_free_client1.part.9+0xf4/0x270 sound/core/seq/seq_clientmgr.c:263 seq_free_client1 sound/core/seq/seq_clientmgr.c:256 [inline] seq_free_client+0x82/0x100 sound/core/seq/seq_clientmgr.c:285 snd_seq_release+0x51/0xe0 sound/core/seq/seq_clientmgr.c:366 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801cf71c0c0 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 88 bytes inside of 512-byte region [ffff8801cf71c0c0, ffff8801cf71c2c0) The buggy address belongs to the page: page:ffffea00073dc700 count:1 mapcount:0 mapping:ffff8801da800940 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea00073a4fc8 ffffea000761f4c8 ffff8801da800940 raw: 0000000000000000 ffff8801cf71c0c0 0000000100000006 0000000000000000 kobject: 'loop5' (00000000172d3417): kobject_uevent_env page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801cf71c000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801cf71c080: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb > ffff8801cf71c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801cf71c180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801cf71c200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller(a)googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with syzbot.

1 0

[alsa-devel] [PATCH v4 00/14] ASoC: Add support to WCD9335 Audio Codec
by srinivas.kandagatla＠linaro.org 24 Oct '18

24 Oct '18

From: Srinivas Kandagatla <srinivas.kandagatla(a)linaro.org> Thankyou for reviewing v3 patchset, here is v4 addressing comments from v3. Qualcomm WCD9335 Codec is a standalone Hi-Fi audio codec IC. It is integrated in multiple Qualcomm SoCs like: MSM8996, MSM8976, and MSM8956 chipsets. WCD9335 had multiple functional blocks, like: Soundwire controller, interrupt mux, pin controller, Audio codec, MBHC, MAD(Mic activity Detection), Ultrasonic proximity and pen detection, Battery-voltage monitoring and Codec processing engine. Currently this patchset has been only tested with SLIMbus interface due to hardware avaiablity, but it can be easily made to work with both SLIMbus and I2C/I2S. This patchset adds very basic playback and capture support witout much fancy features. New features will be added once the basic support is in. This patchset is tested on top of linux-next on DB820c for both playback , capture paths and MBHC. Some parts of the code has been inherited from Qualcomm andriod kernel, so credits to various authors. WCD9335 can be interfaced via I2S/I2C or SLIMbus. Here is my test branch incase someone want to try this out: https://git.linaro.org/people/srinivas.kandagatla/linux.git/log/?h=wcd9335 Thanks, Srini Changes since v3 (https://lkml.org/lkml/2018/9/4/318/) - Updated mbhc dt bindings according to Robs Comments. - Added a cleanup patch to common up fixups. - Addressed various comments on mfd driver by Lee Jones. - Added acks on bindings and irq support. - fixed module loading Srinivas Kandagatla (14): ASoC: dt-bindings: update wcd9335 bindings. mfd: wcd9335: add support to wcd9335 core mfd: wcd9335: add wcd irq support ASoC: wcd9335: add support to wcd9335 codec ASoC: wcd9335: add CLASS-H Controller support ASoC: wcd9335: add basic controls ASoC: wcd9335: add playback dapm widgets ASoC: wcd9335: add capture dapm widgets ASoC: wcd9335: add audio routings ASoC: dt-bindings: Add WCD9335 MBHC specific properties ASoC: wcd9335: add mbhc support ASoC: apq8096: add slim support ASoC: apq8096: add headset JACK support ASoC: qcom: common: move be_hw_fixup to common .../devicetree/bindings/sound/qcom,wcd9335.txt | 30 +- drivers/mfd/Kconfig | 13 + drivers/mfd/Makefile | 4 + drivers/mfd/wcd9335-core.c | 394 ++ include/linux/mfd/wcd9335/registers.h | 640 +++ include/linux/mfd/wcd9335/wcd9335.h | 81 + sound/soc/codecs/Kconfig | 5 + sound/soc/codecs/Makefile | 2 + sound/soc/codecs/wcd-clsh-v2.c | 577 +++ sound/soc/codecs/wcd-clsh-v2.h | 49 + sound/soc/codecs/wcd9335.c | 5241 ++++++++++++++++++++ sound/soc/qcom/apq8096.c | 128 +- sound/soc/qcom/common.c | 17 + sound/soc/qcom/sdm845.c | 22 +- 14 files changed, 7168 insertions(+), 35 deletions(-) create mode 100644 drivers/mfd/wcd9335-core.c create mode 100644 include/linux/mfd/wcd9335/registers.h create mode 100644 include/linux/mfd/wcd9335/wcd9335.h create mode 100644 sound/soc/codecs/wcd-clsh-v2.c create mode 100644 sound/soc/codecs/wcd-clsh-v2.h create mode 100644 sound/soc/codecs/wcd9335.c -- 2.9.3

5 21

[alsa-devel] [asoc:for-4.20 519/528] sound/soc/stm/stm32_sai_sub.c:393:26-32: ERROR: application of sizeof to pointer
by kbuild test robot 24 Oct '18

24 Oct '18

tree: https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-4.20 head: 6be0f96d799f487f05eb412d362d5a1747d665c2 commit: 8307b2afd386ccce369821daa2196068c47fe8cd [519/528] ASoC: stm32: sai: set sai as mclk clock provider coccinelle warnings: (new ones prefixed by >>) >> sound/soc/stm/stm32_sai_sub.c:393:26-32: ERROR: application of sizeof to pointer -- >> sound/soc/stm/stm32_sai_sub.c:343:5-8: WARNING: Unsigned expression compared with zero: div < 0 Please review and possibly fold the followup patch. --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation

3 2

[alsa-devel] Audio miniconference schedule
by Mark Brown 24 Oct '18

24 Oct '18

As previously announced there's an audio miniconference happening on the 21st in Edinburgh: https://blog.sirena.org.uk/2018/09/19/2018-linux-audio-miniconfernce (yes there is a typo in the URL). A number of people have proposed topics so I just went through them and pulled them into a proposed agenda: - Virtualization (Liam) - SoundWire (Liam) - Byte controls (Vinod) - GObject introspection for language bindings (Sakamoto-san) - Integrating the ALSA control core (Sakamoto-san) - AGL (Stephane/Ronan) - Y2038 (broonie) - AVB (Liam) - DSPs (Liam) - Sound Open Firmware What do people think? Any other topics? There's still time to sign up if you're interested in attending, you can sign up right up to the day of the event. It also seems good to mention that there's another audio event going on around ELC: https://blogs.gnome.org/uraeus/2018/09/24/getting-the-team-together-to-revo… which is a hackathon for a new userspace stack called PipeWire - if we have someone attending who knows about that I think it'd be good to talk about it too.

8 24

[alsa-devel] [PATCH - Intervals v2 1/1] interval: Interpret (x x+1] correctly and return x+1
by twischer＠de.adit-jv.com 24 Oct '18

24 Oct '18

From: Timo Wischer <twischer(a)de.adit-jv.com> Without this change an interval of (x x+1] will be interpreted as an empty interval but the right value would be x+1. This leads to a failing snd_pcm_hw_params() call which returns -EINVAL. An example issue log is given in the following: snd_pcm_hw_params failed with err -22 (Invalid argument) ACCESS: MMAP_NONINTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 16 CHANNELS: 1 RATE: 16000 PERIOD_TIME: (15999 16000] PERIOD_SIZE: (255 256] PERIOD_BYTES: (510 512] PERIODS: [2 3) BUFFER_TIME: 32000 BUFFER_SIZE: 512 BUFFER_BYTES: 1024 In case of (x x+1) we have to interpret it anyway as a single value of x to compensate rounding issues. For example the period size will result in an interval of (352 353) when the period time is 16ms and the sample rate 22050 Hz (16ms * 22,05 kHz = 352,8 frames). But 352 has to be chosen to allow a buffer size of 705 (32ms * 22,05 kHz = 705,6 frames) which has to be >= 2x period size to avoid Xruns. The buffer size will not end up with an interval of (705 706) simular to the period size because snd_pcm_rate_hw_refine_cchange() calls snd_interval_floor() for the buffer size. Therefore this value will be interpreted as an integer interval instead of a real interval further on. This issue seems to exist since the change of 9bb985c38 ("pcm: snd_interval_refine_first/last: exclude value only if also excluded before") Signed-off-by: Timo Wischer <twischer(a)de.adit-jv.com> --- > On 10/18/18 12:57, Takashi Iwai wrote: > This change looks risky. The snd_interval_value() might be called > even if the interval isn't reduced to a single value. Rather check > openmin instead. If I would do "if (i->openmin)" on an interval of (x x+1) x+1 would be returned. But this would result in the second issue which I have tried to describe in the commit message: x has to be returned otherwise it is not guaranteed that buffer_size >= 2x period_size. And this would result in continuously Xruns. Therefore I would like to prefer "if (i->openmin && !i->openmax)" diff --git a/src/pcm/interval_inline.h b/src/pcm/interval_inline.h index a68e292..d9a30b2 100644 --- a/src/pcm/interval_inline.h +++ b/src/pcm/interval_inline.h @@ -51,12 +51,14 @@ INTERVAL_INLINE int snd_interval_single(const snd_interval_t *i) { assert(!snd_interval_empty(i)); return (i->min == i->max || - (i->min + 1 == i->max && i->openmax)); + (i->min + 1 == i->max && (i->openmin || i->openmax))); } INTERVAL_INLINE int snd_interval_value(const snd_interval_t *i) { assert(snd_interval_single(i)); + if (i->openmin && !i->openmax) + return i->max; return i->min; } -- 2.7.4

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Re: [alsa-devel] GFP_ATOMIC in Intel code
by Takashi Iwai 24 Oct '18

24 Oct '18

On Tue, 23 Oct 2018 10:49:27 +0200, Vinod wrote: > > On 22-10-18, 12:22, Pierre-Louis Bossart wrote: > > Looking at the latest for-next branch, by accident I saw a number of > > GFP_ATOMIC references. > > > > With my extended break I don't remember much but didn't we agree that none > > of those were needed? If yes I'll send a patch to fix all this. > > > I thought that someone had fixed up all these instances, Looking back at the git history, "someone" was mostly you :) A few of them below seem to be new codes that copied the bad past examples, some are overlooked one, and some are mailbox codes that aren't 100% sure to safe to replace (although I guess it is). > looks like few > missed, so yes please do fix them up and Welcome back :-) I hope you enjoyed the time-off, Pierre. thanks, Takashi > > > Thanks > > > > -Pierre > > > > > > /data/pbossart/ktest/broonie-next/sound/soc/intel$ git grep ATOMIC > > atom/sst/sst_pvt.c: msg = kzalloc(sizeof(struct ipc_post), GFP_ATOMIC); > > atom/sst/sst_pvt.c: msg->mailbox_data = > > kzalloc(SST_MAILBOX_SIZE, GFP_ATOMIC); > > boards/cht_bsw_rt5672.c: drv = devm_kzalloc(&pdev->dev, sizeof(*drv), > > GFP_ATOMIC); > > boards/glk_rt5682_max98357a.c: ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), > > GFP_ATOMIC); > > boards/kbl_da7219_max98927.c: ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), > > GFP_ATOMIC); > > boards/skl_hda_dsp_generic.c: ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), > > GFP_ATOMIC); > > -- > ~Vinod >

2 1

[alsa-devel] [PATCH - AAF PCM plugin 0/7] Introduce AVTP Audio Format (AAF) plugin
by Andre Guedes 23 Oct '18

23 Oct '18

Hi all, The AAF plugin RFC series v2 has been around on alsa-devel ML for more than two weeks so I'm moving forward and sending it as PATCH series now. The first 5 patches from this series are pretty much the same from the previous version. The news are the top 2 patches which add more functionality to the plugin. Patch 6/7 implements the dump() callback which has been useful for debugging purposes and Patch 7/7 adds support for direct read/write transfers. For general context information about the AAF plugin, I'm quoting below the cover letter from the RFC series v1: "This patchset introduces the AAF plugin to the alsa-plugins project which enables TSN audio applications on Linux. For those not familiarized with TSN, it stands for Time-Sensitive Networking, and it's a set of IEEE technologies (enhancements to IEEE 802.1Q and Ethernet protocols) that provide precise time synchronization, bounded latency and application interoperability to bridged networks. Those technologies enable time-sensitive applications such as audio, video and control loops to run on top of bridged networks, co-existing with regular applications. TSN technologies are a super set of Audio Video Bridging (AVB) technologies also developed by IEEE. AVTP is the protocol defined to transport data in a TSN system, and AAF is one of the formats defined by AVTP to encapsulate audio data. AAF is specified in Chapter 7 from the AVTP spec [1]. This work is part of the effort to enable TSN technologies on upstream Linux ecosystem. All building-blocks required to enable TSN audio applications have been already developed and pushed to upstream projects. Time synchronization features are provided by linuxptp project [2], bounded latency features are provided by Linux Traffic Control subsystem since kernel version 4.15 [3], and AVTP packetization is provided by libavtp [4]. What is currently missing in the ecosystem to enable TSN audio applications is a piece of software that plumbs it all together and interfaces with Linux Audio system properly. That's the point of the AAF plugin introduced here. The AAF plugin is a PCM plugin that uses AVTP protocol to transmit / receive audio data through a TSN capable network. When operating in playback mode, the plugin reads PCM samples from the audio buffer, encapsulates into AVTP packets and transmits to the network, mimicking a typical AVTP Talker. When operating in capture mode, the plugin receives AVTP packets from the network, retrieves the PCM samples, and present them to alsa-lib layer at the presentation time, mimicking a typical AVTP Listener." For further information about what has been previously discussed, please refer to RFC series v1 and v2 archives in [5] and [6]. Finally, all versions of this series can be also found in my alsa-plugins tree in github [7]. Best regards, Andre [1] 1722-2016 - IEEE Standard for a Transport Protocol for Time-Sensitive Applications in Bridged Local Area Networks [2] http://linuxptp.sourceforge.net [3] https://patchwork.ozlabs.org/cover/826678/ [4] https://github.com/AVnu/libavtp [5] http://mailman.alsa-project.org/pipermail/alsa-devel/2018-August/139494.html [6] http://mailman.alsa-project.org/pipermail/alsa-devel/2018-September/140290.… [7] https://github.com/aguedes/alsa-plugins Andre Guedes (7): aaf: Introduce plugin skeleton aaf: Load configuration parameters aaf: Implement Playback mode support aaf: Prepare for Capture mode support aaf: Implement Capture mode support aaf: Implement dump() ioplug callback aaf: Add support for direct read/write transfers Makefile.am | 3 + aaf/Makefile.am | 9 + aaf/pcm_aaf.c | 1197 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ configure.ac | 9 + doc/aaf.txt | 142 +++++++ 5 files changed, 1360 insertions(+) create mode 100644 aaf/Makefile.am create mode 100644 aaf/pcm_aaf.c create mode 100644 doc/aaf.txt -- 2.14.4

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