Kernel "oops" when using ALSA

Hi there,

While using the Matrix Voice for a project, I have started to encounter kernel “oops” with the message “Unable to handle kernel paging request”, with an increased frequency as I used more system memory.
Apart from these crashes, everything is working as expected.

The crashes often take around 2-15 minutes to occur whilst my memory use is around 300MB. This continued to occur after a reinstall.

The dmesg output of one of these “oops” is below.

[  227.970616] Unable to handle kernel paging request at virtual address 7f73b000
[  227.974857] pgd = 80004000
[  227.978914] [7f73b000] *pgd=35f88811, *pte=00000000, *ppte=00000000
[  227.983268] Internal error: Oops: 807 [#1] SMP ARM
[  227.987112] Modules linked in: veth xt_nat xt_tcpudp ipt_MASQUERADE nf_nat_masquerade_ipv4 nf_conntrack_netlink nfnetlink iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 xt_addrtype iptable_filter xt_conntrack nf_nat nf_conntrack br_netfilter bridge stp llc overlay bnep hci_uart btbcm serdev bluetooth ecdh_generic matrixio_codec(O) matrixio_pcm(O) snd_soc_core matrixio_uart(O) snd_compress snd_pcm_dmaengine spidev evdev snd_usb_audio snd_hwdep snd_usbmidi_lib snd_rawmidi snd_seq_device brcmfmac brcmutil cfg80211 rfkill spi_bcm2835 fixed uio_pdrv_genirq uio bcm2835_v4l2(C) v4l2_common videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_core videodev media matrixio_env(O) matrixio_imu(O) industrialio matrixio_gpio(O) matrixio_everloop(O) matrixio_regmap(O) matrixio_core(O) snd_dummy
[  228.004965]  snd_pcm snd_timer snd ip_tables x_tables ipv6
[  228.010286] CPU: 0 PID: 163 Comm: kworker/u8:2 Tainted: G         C O    4.14.62-v7+ #1134
[  228.015489] Hardware name: BCM2835
[  228.020386] Workqueue: matrixio_pcm \xffffffa2ꪮ\xffffff8a\xffffffaa\xffffffba\xffffffaa\xffffffea\xffffffea\xffffffaa+\xffffffaa*\xffffffaa\xffffffaa\xffffffab+\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffae\xffffff8b\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffa2\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffff82ꪺ\xffffffae\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffab\xffffffab\xffffffaa*\xffffffaa\xffffffab\xffffffaa\xffffffaa\xffffffaa\xffffffab\xffffffa8\xffffffaa\xffffffaa\xffffffae\xffffffa8\xffffffaa\xffffffab\xffffffaa\xffffffaa\xffffffaa\xffffffba\xffffffa3\xfffffffa\xffffffaa\xffffffaa\xffffffaaꫪʪ\xffffffaa\xffffffaa\xffffffaa\xffffffaa讯\xffffffaa\xffffffaa\xffffffa9\xffffffaa\xffffffaa\xffffffaaꪪ\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffa8쪚\xffffffa8\xffffffa2\xffffffaa\xffffffaa\xffffffab\xffffffaa\xffffffaa\xffffffaa\xffffffaa*\xffffffaa*\xffffffae\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffbaⰪ [matrixio_pcm]
[  228.025944] task: b6e03c00 task.stack: b6f00000
[  228.031454] PC is at memcpy+0x244/0x330
[  228.036675] LR is at 0x1d201e3
[  228.042024] pc : [<80785984>]    lr : [<01d201e3>]    psr: 20000013
[  228.047486] sp : b6f01e90  ip : 01e3022e  fp : b6f01ed4
[  228.052631] r10: 00000000  r9 : 0257024c  r8 : 0231021c
[  228.058038] r7 : 02100206  r6 : 01f201e0  r5 : 01cd01a8  r4 : 01a401f2
[  228.063524] r3 : 02330219  r2 : 00000080  r1 : b88ce314  r0 : 7f73afe4
[  228.068664] Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[  228.074103] Control: 10c5383d  Table: 2d29406a  DAC: 00000055
[  228.079544] Process kworker/u8:2 (pid: 163, stack limit = 0xb6f00210)
[  228.084873] Stack: (0xb6f01e90 to 0xb6f02000)
[  228.090354] 1e80:                                     00000400 b6cf4618 7f73ad04 00000000
[  228.096127] 1ea0: 00000088 7f73ad04 b6cf4610 7f0f915c 00000008 b6eb93b4 00003000 7f6f9d04
[  228.101605] 1ec0: b6eb9398 00000088 b6f01efc b6f01ed8 7f6f7454 7f0f90e4 b6e1b880 b6eb93b4
[  228.107301] 1ee0: b9c14400 b566fd00 00000000 00000088 b6f01f34 b6f01f00 801375b8 7f6f7400
[  228.113108] 1f00: b9c14418 80c02d00 00000088 b9c14400 b6e1b898 b9c14400 b9c14418 80c02d00
[  228.118179] 1f20: 00000088 b6e1b880 b6f01f7c b6f01f38 80137918 8013746c b6f01f5c b6f00000
[  228.123470] 1f40: 00000000 80c02d00 80c882e2 b6f00038 b8ad4e9c b8ad4e80 00000000 b6e21400
[  228.129205] 1f60: b6e1b880 801378b4 b8ad4e9c b9d0de80 b6f01fac b6f01f80 8013d99c 801378c0
[  228.134690] 1f80: 40000700 b6e21400 8013d860 00000000 00000000 00000000 00000000 00000000
[  228.140647] 1fa0: 00000000 b6f01fb0 8010810c 8013d86c 00000000 00000000 00000000 00000000
[  228.146493] 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[  228.151992] 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
[  228.157789] [<80785984>] (memcpy) from [<7f0f915c>] (matrixio_read+0x84/0xa8 [matrixio_core])
[  228.163640] [<7f0f915c>] (matrixio_read [matrixio_core]) from [<7f6f7454>] (\xffffffa2ꪮ\xffffff8a\xffffffaa\xffffffba\xffffffaa\xffffffea\xffffffea\xffffffaa+\xffffffaa*\xffffffaa\xffffffaa\xffffffab+\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffae\xffffff8b\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffa2\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffff82ꪺ\xffffffae\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffab\xffffffab\xffffffaa*\xffffffaa\xffffffab\xffffffaa\xffffffaa\xffffffaa\xffffffab\xffffffa8\xffffffaa\xffffffaa\xffffffae\xffffffa8\xffffffaa\xffffffab\xffffffaa\xffffffaa\xffffffaa\xffffffba\xffffffa3\xfffffffa\xffffffaa\xffffffaa\xffffffaaꫪʪ\xffffffaa\xffffffaa\xffffffaa\xffffffaa讯\xffffffaa\xffffffaa\xffffffa9\xffffffaa\xffffffaa\xffffffaaꪪ\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffa8쪚\xffffffa8\xffffffa2\xffffffaa\xffffffaa\xffffffab\xffffffaa\xffffffaa\xffffffaa\xffffffaa*\xffffffaa*\xffffffae\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffbaⰪ+0x7c50714c/0x7c507cf8 [matrixio_pcm])
[  228.176048] [<7f6f7454>] (\xffffffa2ꪮ\xffffff8a\xffffffaa\xffffffba\xffffffaa\xffffffea\xffffffea\xffffffaa+\xffffffaa*\xffffffaa\xffffffaa\xffffffab+\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffae\xffffff8b\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffa2\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffff82ꪺ\xffffffae\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffab\xffffffab\xffffffaa*\xffffffaa\xffffffab\xffffffaa\xffffffaa\xffffffaa\xffffffab\xffffffa8\xffffffaa\xffffffaa\xffffffae\xffffffa8\xffffffaa\xffffffab\xffffffaa\xffffffaa\xffffffaa\xffffffba\xffffffa3\xfffffffa\xffffffaa\xffffffaa\xffffffaaꫪʪ\xffffffaa\xffffffaa\xffffffaa\xffffffaa讯\xffffffaa\xffffffaa\xffffffa9\xffffffaa\xffffffaa\xffffffaaꪪ\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffa8쪚\xffffffa8\xffffffa2\xffffffaa\xffffffaa\xffffffab\xffffffaa\xffffffaa\xffffffaa\xffffffaa*\xffffffaa*\xffffffae\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffaa\xffffffbaⰪ [matrixio_pcm]) from [<801375b8>] (process_one_work+0x158/0x454)
[  228.182794] [<801375b8>] (process_one_work) from [<80137918>] (worker_thread+0x64/0x5b8)
[  228.189388] [<80137918>] (worker_thread) from [<8013d99c>] (kthread+0x13c/0x16c)
[  228.196295] [<8013d99c>] (kthread) from [<8010810c>] (ret_from_fork+0x14/0x28)
[  228.202932] Code: e1a09829 e189980c e1a0c82c e18cc80e (e8a013f8) 
[  228.210445] ---[ end trace 2134a6e81a0f363d ]---

Unfortunately, my project is pretty all over the place as of now so sharing it is difficult and I have not been able to isolate the issues in an example program that also causes the crash. However, I will attempt to do so soon if I have some spare time.

For reference, my project interacts with the matrix voice via ODAS to track sources and via the provided python code for the everloop to provide feedback.

From my searches I could not seem to find anyone else who is encountering the issue regarding matrix devices, however some other people encountering similar causes for kernel "oops"s talk about the use of slub_debug bootflag to aid debugging.

I have been testing this flag, and found it consistently triggers a kernel “oops” when performing an arecord on a fresh install, which I believe could have the same cause as my original issue.

An example of the dmesg output from the above method is below.

[  358.771969] Unable to handle kernel paging request at virtual address cccccd1c
[  358.778146] pgd = a4af0000
[  358.784070] [cccccd1c] *pgd=00000000
[  358.790013] Internal error: Oops: 5 [#1] SMP ARM
[  358.795992] Modules linked in: cmac bnep hci_uart btbcm serdev bluetooth ecdh_generic matrixio_codec(O) matrixio_pcm(O) spidev snd_soc_core snd_compress snd_pcm_dmaengine matrixio_uart(O) brcmfmac brcmutil cfg80211 rfkill spi_bcm2835 uio_pdrv_genirq uio fixed bcm2835_v4l2(C) v4l2_common videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_core videodev media matrixio_env(O) matrixio_imu(O) industrialio matrixio_gpio(O) matrixio_everloop(O) matrixio_regmap(O) matrixio_core(O) snd_dummy snd_bcm2835(C) snd_pcm snd_timer snd ip_tables x_tables ipv6
[  358.817038] CPU: 0 PID: 1454 Comm: arecord Tainted: G         C O    4.14.62-v7+ #1134
[  358.824227] Hardware name: BCM2835
[  358.829639] task: a4826cc0 task.stack: a4834000
[  358.832976] PC is at soc_pcm_open+0x17c/0x8a0 [snd_soc_core]
[  358.836116] LR is at proc_register+0xd4/0x150
[  358.839340] pc : [<7f5f1670>]    lr : [<802fc830>]    psr: 60000013
[  358.842630] sp : a4835c90  ip : a4835ae0  fp : a4835cf4
[  358.845935] r10: 00000000  r9 : b939431c  r8 : a511d640
[  358.849234] r7 : 00000000  r6 : a5209708  r5 : a575de40  r4 : a5209100
[  358.852448] r3 : cccccccc  r2 : a499fb74  r1 : a499f96c  r0 : 00000000
[  358.855720] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[  358.859065] Control: 10c5383d  Table: 24af006a  DAC: 00000055
[  358.862425] Process arecord (pid: 1454, stack limit = 0xa4834210)
[  358.865818] Stack: (0xa4835c90 to 0xa4836000)
[  358.869100] 5c80:                                     ffffffff 00000011 000f4240 00000009
[  358.872501] 5ca0: a4b879c0 0000000d a4835cf4 a520914c a4b879c0 b93bd840 000f4240 00000011
[  358.875983] 5cc0: 0000000b ffffffff a4835cfc 00000000 a4835d20 00000000 b9394308 00000001
[  358.879494] 5ce0: b939431c 00000000 a4835d14 a4835cf8 7f0d0f18 7f5f1500 8079fb78 a575de40
[  358.883046] 5d00: b9393f40 a4a3fb40 a4835d64 a4835d18 7f0d102c 7f0d0ebc a520ccc0 a4834018
[  358.886439] 5d20: 00000003 00000000 a4826cc0 80148f58 b9394320 b9394320 a520d04c a4a3fb40
[  358.889987] 5d40: b9393f40 a4a3fb40 a5330580 a51c9478 00000000 00000000 a4835d7c a4835d68
[  358.893595] 5d60: 7f0d11d0 7f0d0f80 7f0d76b8 7f0ac300 a4835da4 a4835d80 7f0a15d4 7f0d1190
[  358.897239] 5d80: 7f0a1524 7f0a937c 80d11538 b7945580 a51c9478 a4a3fb40 a4835dd4 a4835da8
[  358.900886] 5da0: 8028f778 7f0a1530 a4a3fb48 00000058 a4a3fb40 a51c9478 a4a3fb48 8028f698
[  358.904365] 5dc0: 00000000 a4835f5c a4835dfc a4835dd8 80286e20 8028f6a4 a4a3fb40 a4835ea8
[  358.908016] 5de0: a4871280 a51c9478 00000000 a4835f5c a4835e1c a4835e00 802880cc 80286c2c
[  358.911686] 5e00: a4826cc0 a4835ea8 00000000 00000802 a4835ea4 a4835e20 80299690 8028807c
[  358.915343] 5e20: 80276d6c 80276364 60000013 8029a904 ba8d90c0 b9c008c0 00070001 a4834000
[  358.918932] 5e40: a4835e64 a4835e50 00000041 a4a3fb40 00000000 00000006 00000000 00000002
[  358.922543] 5e60: a51c9478 b9d08a50 b89c6008 7f0a55ac 40045532 7f0cb070 b909a100 00000004
[  358.926252] 5e80: a4835f5c a4835ea8 00000001 80108204 a4834000 00000000 a4835f4c a4835ea8
[  358.929988] 5ea0: 8029b670 802993d4 b9d08a50 b89c6008 7371274c 00000008 a52b6359 8029a904
[  358.933742] 5ec0: 00000000 b9a8dab8 a51c9478 00000101 00000002 00000494 00000000 00000000
[  358.937384] 5ee0: 00000000 a4835ee8 ffffff9c 00000004 b6e0e340 b909af40 00000000 00000400
[  358.941194] 5f00: a4835f3c a4835f10 802ab0f0 802aa864 00080802 00080802 a52b6340 00000000
[  358.945022] 5f20: 00000005 00000002 ffffff9c 00000000 00000004 ffffff9c a52b6340 00000005
[  358.948872] 5f40: a4835f94 a4835f50 802884a8 8029b60c a4835fa4 a4a3f740 7ee0e14c 00000802
[  358.952657] 5f60: 40040000 00000006 00000100 00000001 00080802 ffffffff 00000000 00000005
[  358.956525] 5f80: 80108204 a4834000 a4835fa4 a4835f98 80288584 80288394 00000000 a4835fa8
[  358.960460] 5fa0: 80108060 80288564 00080802 ffffffff 7ee0e29c 00080802 00404000 00404000
[  358.964438] 5fc0: 00080802 ffffffff 00000000 00000005 76ef6394 7ee0e17c 7ee0e29c 00000001
[  358.968400] 5fe0: 00000000 7ee0e154 76e642bc 76cd1c3c 60000010 7ee0e29c 00000000 00000000
[  358.972385] [<7f5f1670>] (soc_pcm_open [snd_soc_core]) from [<7f0d0f18>] (snd_pcm_open_substream+0x68/0xc4 [snd_pcm])
[  358.976543] [<7f0d0f18>] (snd_pcm_open_substream [snd_pcm]) from [<7f0d102c>] (snd_pcm_open+0xb8/0x210 [snd_pcm])
[  358.980752] [<7f0d102c>] (snd_pcm_open [snd_pcm]) from [<7f0d11d0>] (snd_pcm_capture_open+0x4c/0x70 [snd_pcm])
[  358.984954] [<7f0d11d0>] (snd_pcm_capture_open [snd_pcm]) from [<7f0a15d4>] (snd_open+0xb0/0x154 [snd])
[  358.989069] [<7f0a15d4>] (snd_open [snd]) from [<8028f778>] (chrdev_open+0xe0/0x1a0)
[  358.993328] [<8028f778>] (chrdev_open) from [<80286e20>] (do_dentry_open+0x200/0x328)
[  358.997600] [<80286e20>] (do_dentry_open) from [<802880cc>] (vfs_open+0x5c/0x8c)
[  359.001805] [<802880cc>] (vfs_open) from [<80299690>] (path_openat+0x2c8/0xff8)
[  359.005949] [<80299690>] (path_openat) from [<8029b670>] (do_filp_open+0x70/0xd4)
[  359.010235] [<8029b670>] (do_filp_open) from [<802884a8>] (do_sys_open+0x120/0x1d0)
[  359.014551] [<802884a8>] (do_sys_open) from [<80288584>] (SyS_open+0x2c/0x30)
[  359.018654] [<80288584>] (SyS_open) from [<80108060>] (ret_fast_syscall+0x0/0x28)
[  359.022567] Code: e5943584 e15a0003 3affffe8 e5943008 (e5932050) 
[  359.026419] ---[ end trace dcd70b617fb8cbf2 ]---

To recreate this second crash with the flag, I performed the following actions:

  1. apt-get update, apt-get dist-upgrade
  2. Followed these instructions, installing matrixio-malos
  3. Installed matrixio-creator-init, libmatrixio-creator-hal, libmatrixio-creator-hal-dev, matrixio-kernel-modules, restarting inbetween as outlined here
  4. Appended slub_debug=FZ to the end of the line of /boot/cmdline.txt
  5. Ran arecord and checked dmesg after

I am using a raspberry pi 3B+, however the error seems to occur on a Raspberry Pi 3B v1.2 aswell.

The outputs for the commands in the pinned post are as follows:

FPGA IDENTIFY = 6032bad2
FPGA VERSION = 1000a
gpiochip0: GPIOs 0-53, parent: platform/3f200000.gpio, pinctrl-bcm2835:
 gpio-18  (                    |sysfs               ) out hi    
 gpio-24  (                    |sysfs               ) out hi    
 gpio-25  (                    |sysfs               ) out hi    
 gpio-26  (                    |sysfs               ) out hi    
 gpio-29  (                    |led0                ) out lo    

gpiochip1: GPIOs 128-135, brcmexp-gpio, can sleep:
 gpio-130 (                    |led1                ) out lo    

gpiochip2: GPIOs 496-511, parent: spi/spi0.0, matrixio-gpio, can sleep:

Thanks for the help :slight_smile:

1 Like

nicolaus,

I am having exactly the same issue over here – except with the MATRIX Creator instead of the Voice. This is with the Raspberry Pi 3B.
We have a multithreaded application in Python that reads audio from the MATRIX Creator in one process (using the multiprocessing library with pyalsaaudio) and does some calculations on that audio in another process. We’ve tried using both pyalsaaudio and pyaudio for getting at the Creator and we get the same kernel panic after it runs for some time. Here’s the kernel panic we get; it appears to be identical to yours:

– Logs begin at Thu 2019-07-25 00:22:33 GMT, end at Thu 2019-07-25 00:57:07 GMT. –
Jul 25 00:30:49 raspberrypi kernel: Unable to handle kernel paging request at virtual address 7f1fa000
Jul 25 00:30:50 raspberrypi kernel: pgd = c64940be
Jul 25 00:30:54 raspberrypi kernel: [7f1fa000] *pgd=38d1a811, *pte=00000000, *ppte=00000000
Jul 25 00:30:55 raspberrypi kernel: Internal error: Oops: 807 [#1] SMP ARM
Jul 25 00:30:56 raspberrypi kernel: Modules linked in: rfcomm bnep hci_uart btbcm serdev bluetooth ecdh_generic matrixio_uart(O) spidev evdev brcmfmac brcmutil sha256_generic cfg80211 rfkill raspberrypi_hwmon hwmon bcm2835_codec© v4l2_mem2mem i2c_bcm2835 videobuf2_dma_contig spi_bcm2835 uio_pdrv_genirq fixed uio bcm2835_v4l2© bcm2835_mmal_vchiq© vc_sm_cma© v4l2_common videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev media i2c_dev matrixio_codec(O) matrixio_playback(O) matrixio_mic(O) snd_soc_core snd_compress snd_pcm_dmaengine matrixio_env(O) matrixio_imu(O) industrialio matrixio_gpio(O) matrixio_everloop(O) matrixio_regmap(O) matrixio_core(O) snd_dummy snd_bcm2835© snd_pcm snd_timer snd ip_tables x_tables ipv6
Jul 25 00:30:56 raspberrypi kernel: CPU: 0 PID: 964 Comm: kworker/0:1 Tainted: G C O 4.19.42-v7+ #1219
Jul 25 00:30:56 raspberrypi kernel: Hardware name: BCM2835
Jul 25 00:30:56 raspberrypi kernel: [160B blob data]
Jul 25 00:30:56 raspberrypi kernel: PC is at memcpy+0x244/0x330
Jul 25 00:30:56 raspberrypi kernel: LR is at 0x17a0179
Jul 25 00:30:56 raspberrypi kernel: pc : [<8080d1c4>] lr : [<017a0179>] psr: 20000013
Jul 25 00:30:56 raspberrypi kernel: sp : b29f1e90 ip : 01790185 fp : b29f1ed4
Jul 25 00:30:56 raspberrypi kernel: r10: 00000000 r9 : 01900187 r8 : 01800180
Jul 25 00:30:56 raspberrypi kernel: r7 : 018d019b r6 : 019a0194 r5 : 01a00198 r4 : 01810185
Jul 25 00:30:56 raspberrypi kernel: r3 : 01910187 r2 : 00000100 r1 : b9cc02c4 r0 : 7f1f9fe4
Jul 25 00:30:56 raspberrypi kernel: Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
Jul 25 00:30:56 raspberrypi kernel: Control: 10c5383d Table: 38d4406a DAC: 00000055
Jul 25 00:30:56 raspberrypi kernel: Process kworker/0:1 (pid: 964, stack limit = 0xeddb216a)
Jul 25 00:30:56 raspberrypi kernel: Stack: (0xb29f1e90 to 0xb29f2000)
Jul 25 00:31:01 raspberrypi kernel: 1e80: 00000400 b7883048 7f1f9d84 00000000
Jul 25 00:31:01 raspberrypi kernel: 1ea0: b7ad5d28 7f1f9d84 b7883040 7f10a18c 00000008 b7ad5d24 00003000 7f1b8d84
Jul 25 00:31:01 raspberrypi kernel: 1ec0: b7ad5d08 b7ad5d28 b29f1efc b29f1ed8 7f1b6454 7f10a10c b9e33a80 b7ad5d24
Jul 25 00:31:01 raspberrypi kernel: 1ee0: ba350a40 ba353c00 00000000 b7ad5d28 b29f1f34 b29f1f00 8013bd7c 7f1b6400
Jul 25 00:31:01 raspberrypi kernel: 1f00: 40000093 ba350a40 ba350a40 ba350a40 b9e33a94 ba350a40 ba350a58 80d03d00
Jul 25 00:31:01 raspberrypi kernel: 1f20: 00000008 b9e33a80 b29f1f7c b29f1f38 8013c0c0 8013bc18 b29f1f5c b29f1f48
Jul 25 00:31:01 raspberrypi kernel: 1f40: 8082c284 80d03d00 80d8e43a b29f0038 b29f1f7c b2888380 b786e900 00000000
Jul 25 00:31:01 raspberrypi kernel: 1f60: b9e33a80 8013c064 b288839c b5713e74 b29f1fac b29f1f80 801423ac 8013c070
Jul 25 00:31:01 raspberrypi kernel: 1f80: 801042f8 b786e900 80142274 00000000 00000000 00000000 00000000 00000000
Jul 25 00:31:01 raspberrypi kernel: 1fa0: 00000000 b29f1fb0 801010ac 80142280 00000000 00000000 00000000 00000000
Jul 25 00:31:01 raspberrypi kernel: 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
Jul 25 00:31:01 raspberrypi kernel: 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
Jul 25 00:31:01 raspberrypi kernel: [<8080d1c4>] (memcpy) from [<7f10a18c>] (matrixio_read+0x8c/0x9c [matrixio_core])
Jul 25 00:31:01 raspberrypi kernel: [229B blob data]
Jul 25 00:31:01 raspberrypi kernel: [206B blob data]
Jul 25 00:31:01 raspberrypi kernel: [<8013bd7c>] (process_one_work) from [<8013c0c0>] (worker_thread+0x5c/0x5a4)
Jul 25 00:31:01 raspberrypi kernel: [<8013c0c0>] (worker_thread) from [<801423ac>] (kthread+0x138/0x168)
Jul 25 00:31:01 raspberrypi kernel: [<801423ac>] (kthread) from [<801010ac>] (ret_from_fork+0x14/0x28)
Jul 25 00:31:01 raspberrypi kernel: Exception stack(0xb29f1fb0 to 0xb29f1ff8)
Jul 25 00:31:01 raspberrypi kernel: 1fa0: 00000000 00000000 00000000 00000000
Jul 25 00:31:01 raspberrypi kernel: 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
Jul 25 00:31:01 raspberrypi kernel: 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000
Jul 25 00:31:01 raspberrypi kernel: Code: e1a09829 e189980c e1a0c82c e18cc80e (e8a013f8)
Jul 25 00:31:01 raspberrypi kernel: —[ end trace 0eabcf86ddb89992 ]—

Have you managed to find a solution to this issue? If so, please let me know, if it’s not too much trouble.

Thank you.

It’s my belief that there’s something wonky going on in the ALSA bit of the MATRIX kernel modules. I ended up modifying the HAL to let me at the collected raw audio, wrapped that in Python with ctypes, and replaced my pyalsaaudio calls to use audio collection from that version of the HAL. Everything appears to be entirely stable, now.