Bug#1108496: linux-image-6.12.30+bpo-amd64: USB audio glitches: retire_capture_urb
It seems like the periodic glitching is related to hw_random.
A glitch happens every time the hwrng process becomes active, every ~60
seconds, and can be reproduced on demand by reading 64 bytes.
# od -Ad -N64 < /dev/hwrng
0000000 136705 146445 104226 000714 065106 122636 025711 113316
0000016 030251 142732 153350 046337 135743 007723 167576 052533
0000032 020014 064122 155565 000156 052467 105312 043434 142123
0000048 051052 142223 035427 154113 163333 154443 052143 127476
0000064
I can't reproduce this in 6.1.
The kernel log for 6.1 includes "No test for fips(ansi_cprng)
(fips_ansi_cprng)", whereas 6.12 doesn't, but in either case fips is not
enabled.
# cat /proc/sys/crypto/fips_enabled
0
Jamie
-- Boot 4475684080d44d0685874913b7610c5e --
Aug 02 00:42:02 kassia kernel: Linux version 6.1.0-37-amd64 (debian-kernel@lists.debian.org) (gcc-12 (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40) #1 SMP PREEMPT_DYNAMIC Debian 6.1.140-1 (2025-05-22)
Aug 02 00:42:02 kassia kernel: efi: ACPI=0x94bfe000 ACPI 2.0=0x94bfe014 TPMFinalLog=0x9498f000 SMBIOS=0x90cbb000 SMBIOS 3.0=0x90cae000 MEMATTR=0x8b52f018 ESRT=0x8b66c000
Aug 02 00:42:02 kassia kernel: ACPI: SSDT 0x0000000090CBD000 00060E (v02 LENOVO Tpm2Tabl 00001000 INTL 20191018)
Aug 02 00:42:02 kassia kernel: ACPI: TPM2 0x0000000090CBC000 00004C (v04 LENOVO TP-N34 00001640 PTEC 00000002)
Aug 02 00:42:02 kassia kernel: ACPI: Reserving TPM2 table memory at [mem 0x90cbc000-0x90cbc04b]
Aug 02 00:42:02 kassia kernel: random: crng init done
Aug 02 00:42:02 kassia kernel: tpm_tis STM0125:00: 2.0 TPM (device-id 0x0, rev-id 78)
Aug 02 00:42:02 kassia systemd[1]: systemd 254.26-1~bpo12+1 running in system mode (+PAM +AUDIT +SELINUX +APPARMOR +IMA +SMACK +SECCOMP +GCRYPT -GNUTLS +OPENSSL +ACL +BLKID +CURL +ELFUTILS +FIDO2 +IDN2 -IDN +IPTC +KMOD +LIBCRYPTSETUP +LIBFDISK +PCRE2 -PWQUALITY +P11KIT +QRENCODE +TPM2 +BZIP2 +LZ4 +XZ +ZLIB +ZSTD -BPF_FRAMEWORK -XKBCOMMON +UTMP +SYSVINIT default-hierarchy=unified)
Aug 02 00:42:02 kassia systemd[1]: systemd-pcrmachine.service - TPM2 PCR Machine ID Measurement was skipped because of an unmet condition check (ConditionPathExists=/sys/firmware/efi/efivars/StubPcrKernelImage-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f).
Aug 02 00:42:02 kassia systemd[1]: Starting systemd-random-seed.service - Load/Save OS Random Seed...
Aug 02 00:42:02 kassia systemd[1]: Finished systemd-random-seed.service - Load/Save OS Random Seed.
Aug 02 00:42:02 kassia systemd[1]: systemd-pcrmachine.service - TPM2 PCR Machine ID Measurement was skipped because of an unmet condition check (ConditionPathExists=/sys/firmware/efi/efivars/StubPcrKernelImage-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f).
Aug 02 00:42:02 kassia kernel: alg: No test for fips(ansi_cprng) (fips_ansi_cprng)
Aug 02 00:42:03 kassia systemd[1]: systemd-pcrmachine.service - TPM2 PCR Machine ID Measurement was skipped because of an unmet condition check (ConditionPathExists=/sys/firmware/efi/efivars/StubPcrKernelImage-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f).
Aug 02 00:42:03 kassia systemd[1]: systemd-pcrmachine.service - TPM2 PCR Machine ID Measurement was skipped because of an unmet condition check (ConditionPathExists=/sys/firmware/efi/efivars/StubPcrKernelImage-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f).
Aug 02 00:42:03 kassia systemd[1]: systemd-pcrphase-sysinit.service - TPM2 PCR Barrier (Initialization) was skipped because of an unmet condition check (ConditionPathExists=/sys/firmware/efi/efivars/StubPcrKernelImage-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f).
Aug 02 00:42:03 kassia systemd[1]: systemd-pcrphase.service - TPM2 PCR Barrier (User) was skipped because of an unmet condition check (ConditionPathExists=/sys/firmware/efi/efivars/StubPcrKernelImage-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f).
-- Boot 39d396b04fa540fe81a8958ad5b3b6ee --
Aug 02 01:06:29 kassia kernel: Linux version 6.12.33+deb12-amd64 (debian-kernel@lists.debian.org) (x86_64-linux-gnu-gcc-12 (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40) #1 SMP PREEMPT_DYNAMIC Debian 6.12.33-1~bpo12+1 (2025-07-09)
Aug 02 01:06:29 kassia kernel: efi: ACPI=0x94bfe000 ACPI 2.0=0x94bfe014 TPMFinalLog=0x9498f000 SMBIOS=0x90cbb000 SMBIOS 3.0=0x90cae000 MEMATTR=0x8b530018 ESRT=0x8b66d000
Aug 02 01:06:29 kassia kernel: ACPI: SSDT 0x0000000090CBD000 00060E (v02 LENOVO Tpm2Tabl 00001000 INTL 20191018)
Aug 02 01:06:29 kassia kernel: ACPI: TPM2 0x0000000090CBC000 00004C (v04 LENOVO TP-N34 00001640 PTEC 00000002)
Aug 02 01:06:29 kassia kernel: ACPI: Reserving TPM2 table memory at [mem 0x90cbc000-0x90cbc04b]
Aug 02 01:06:29 kassia kernel: random: crng init done
Aug 02 01:06:29 kassia kernel: tpm_tis STM0125:00: 2.0 TPM (device-id 0x0, rev-id 78)
Aug 02 01:06:29 kassia systemd[1]: systemd 254.26-1~bpo12+1 running in system mode (+PAM +AUDIT +SELINUX +APPARMOR +IMA +SMACK +SECCOMP +GCRYPT -GNUTLS +OPENSSL +ACL +BLKID +CURL +ELFUTILS +FIDO2 +IDN2 -IDN +IPTC +KMOD +LIBCRYPTSETUP +LIBFDISK +PCRE2 -PWQUALITY +P11KIT +QRENCODE +TPM2 +BZIP2 +LZ4 +XZ +ZLIB +ZSTD -BPF_FRAMEWORK -XKBCOMMON +UTMP +SYSVINIT default-hierarchy=unified)
Aug 02 01:06:29 kassia systemd[1]: systemd-pcrmachine.service - TPM2 PCR Machine ID Measurement was skipped because of an unmet condition check (ConditionPathExists=/sys/firmware/efi/efivars/StubPcrKernelImage-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f).
Aug 02 01:06:29 kassia systemd[1]: Starting systemd-random-seed.service - Load/Save OS Random Seed...
Aug 02 01:06:29 kassia systemd[1]: Finished systemd-random-seed.service - Load/Save OS Random Seed.
Aug 02 01:06:29 kassia systemd[1]: systemd-pcrmachine.service - TPM2 PCR Machine ID Measurement was skipped because of an unmet condition check (ConditionPathExists=/sys/firmware/efi/efivars/StubPcrKernelImage-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f).
Aug 02 01:06:29 kassia systemd[1]: systemd-pcrmachine.service - TPM2 PCR Machine ID Measurement was skipped because of an unmet condition check (ConditionPathExists=/sys/firmware/efi/efivars/StubPcrKernelImage-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f).
Aug 02 01:06:30 kassia systemd[1]: systemd-pcrmachine.service - TPM2 PCR Machine ID Measurement was skipped because of an unmet condition check (ConditionPathExists=/sys/firmware/efi/efivars/StubPcrKernelImage-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f).
Aug 02 01:06:30 kassia systemd[1]: systemd-pcrphase-sysinit.service - TPM2 PCR Barrier (Initialization) was skipped because of an unmet condition check (ConditionPathExists=/sys/firmware/efi/efivars/StubPcrKernelImage-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f).
Aug 02 01:06:30 kassia systemd[1]: systemd-pcrphase.service - TPM2 PCR Barrier (User) was skipped because of an unmet condition check (ConditionPathExists=/sys/firmware/efi/efivars/StubPcrKernelImage-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f).
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