Hello,

I have a Lenovo Thinkpad, running Debian Trixie.

I have enabled TPM and IOMMU in the BIOS

However, when I boot the laptop, I cannot have both options working
together. It is either tpm2 or iommu, but not both.

If I add "iommu=off" on the Linux command line, the TPM is working. If
I don't do anything. IOMMU is working. but the TPM2 chip is not found:

I have secure boot enabled.

Kernel: Linux lovelace 6.18.5+deb13-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.18.5-1~bpo13+1 (2026-02-04) x86_64 GNU/Linux

Any idea why, please ?


Thanks for your help.

--- PyGate Linux v1.5.11
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Hello,

I have a Lenovo Thinkpad T460, running Debian Trixie.

I have enabled TPM and IOMMU in the BIOS.

However, when I boot the laptop, I cannot have both options working
together. It is either tpm2 or iommu, but not both.

If I add "iommu=off" on the Linux command line, the TPM is working. If
I don't do anything. IOMMU is working. but the TPM2 chip is not found:

I have secure boot enabled, and working.

Here some boot messages:

Feb 21 08:46:41 lovelace kernel: Linux version 6.18.5+deb13-amd64 (debian-kernel@lists.debian.org) (x86_64-linux-gnu-gcc-14 (Debian
14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44) #1 SMP PREEMPT_DYNAMIC Debian 6.18.5-1~bpo13+1 (2026-02-04)
Feb 21 08:46:41 lovelace kernel: Command line: BOOT_IMAGE=/vmlinuz- 6.18.5+deb13-amd64 root=/dev/mapper/safe-sys ro splash intel_iommu=on iommu=pt i915.preliminary_hw_support=1 tpm_tis.force=1 quiet
Feb 21 08:46:41 lovelace kernel: BIOS-provided physical RAM map:
--
Feb 21 08:46:41 lovelace kernel: efi: EFI v2.4 by Lenovo
Feb 21 08:46:41 lovelace kernel: efi: SMBIOS=0xaee0f000
ACPI=0xafffd000 ACPI 2.0=0xafffd014 ESRT=0xaec9e000 MOKvar=0xaec8

3000

INITRD=0x9dc5a818 RNG=0xaffcbf98 TPMEventLog=0x9289b018
Feb 21 08:46:41 lovelace kernel: random: crng init done
Feb 21 08:46:41 lovelace kernel: TPM Final Events table not present
Feb 21 08:46:41 lovelace kernel: efi: Not removing mem65: MMIO range=[0xf80fa000-0xf80fafff] (4KB) from e820 map
--
Feb 21 08:46:41 lovelace kernel: ACPI: TCPA 0x00000000AFFFB000 000032
(v02 LENOVO TP-R06 00000002 PTEC 00000002)
Feb 21 08:46:41 lovelace kernel: ACPI: SSDT 0x00000000AFFFA000 0004B7
(v02 LENOVO Tpm2Tabl 00001000 INTL 20141107)
Feb 21 08:46:41 lovelace kernel: ACPI: SSDT 0x00000000AFFF9000 00004B
(v02 LENOVO MeSsdt 00003000 INTL 20141107)
Feb 21 08:46:41 lovelace kernel: ACPI: TPM2 0x00000000AFFF8000 000034
(v03 LENOVO TP-R06 00001450 PTEC 00000002)
Feb 21 08:46:41 lovelace kernel: ACPI: UEFI 0x00000000AFFA6000 000042
(v01 LENOVO TP-R06 00001450 PTEC 00000002)
--
Feb 21 08:46:41 lovelace kernel: ACPI: Reserving SSDT table memory at
[mem 0xafff9000-0xafff904a]
Feb 21 08:46:41 lovelace kernel: ACPI: Reserving TPM2 table memory at
[mem 0xafff8000-0xafff8033]
Feb 21 08:46:41 lovelace kernel: ACPI: Reserving UEFI table memory at
[mem 0xaffa6000-0xaffa6041]
--
Feb 21 08:46:41 lovelace kernel: pcpu-alloc: [0] 0 1 2 3
Feb 21 08:46:41 lovelace kernel: Kernel command line: BOOT_IMAGE=/vmlinuz-6.18.5+deb13-amd64 root=/dev/mapper/safe-sys ro
splash intel_iommu=on iommu=pt i915.preliminary_hw_support=1
tpm_tis.force=1 quiet
Feb 21 08:46:41 lovelace kernel: DMAR: IOMMU enabled
--
Feb 21 08:46:41 lovelace kernel: Linux agpgart interface v0.103
Feb 21 08:46:41 lovelace kernel: tpm_tis tpm_tis: error -EBUSY: can't
request region for resource [mem 0xfed40000-0xfed44fff]
Feb 21 08:46:41 lovelace kernel: tpm_tis tpm_tis: probe with driver
tpm_tis failed with error -16
Feb 21 08:46:41 lovelace kernel: DMAR: DRHD: handling fault status
reg 3
--
Feb 21 08:46:41 lovelace kernel: clocksource: Switched to clocksource
tsc
Feb 21 08:46:41 lovelace kernel: tpm tpm0: Operation Timed out
Feb 21 08:46:41 lovelace kernel: tpm tpm0: Operation Timed out
Feb 21 08:46:41 lovelace kernel: tpm_crb MSFT0101:00: probe with
driver tpm_crb failed with error -62
Feb 21 08:46:41 lovelace kernel: i8042: PNP: PS/2 Controller [PNP0303:KBD,PNP0f13:MOU] at 0x60,0x64 irq 1,12
--
Feb 21 08:46:41 lovelace kernel: integrity: Loaded X.509 cert 'Debian
Secure Boot CA: 6ccece7e4c6c0d1f6149f3dd27dfcc5cbb419ea1'
Feb 21 08:46:41 lovelace kernel: ima: No TPM chip found, activating TPM-bypass!
Feb 21 08:46:41 lovelace kernel: ima: Allocated hash algorithm:
sha256
--
Feb 21 08:46:42 lovelace systemd[1]: Inserted module 'autofs4'
Feb 21 08:46:42 lovelace systemd[1]: systemd 257.9-1~deb13u1 running
in system mode (+PAM +AUDIT +SELINUX +APPARMOR +IMA +IPE +SMACK
+SECCOMP +GCRYPT -GNUTLS +OPENSSL +ACL +BLKID +CURL +ELFUTILS +FIDO2
+IDN2 -IDN +IPTC +KMOD +LIBCRYPTSETUP +LIBCRYPTSETUP_PLUGINS
+LIBFDISK +PCRE2 +PWQUALITY +P11KIT +QRENCODE +TPM2 +BZIP2 +LZ4 +XZ
+ZLIB +ZSTD +BPF_FRAMEWORK +BTF -XKBCOMMON -UTMP +SYSVINIT
+LIBARCHIVE)
Feb 21 08:46:42 lovelace systemd[1]: Detected architecture x86-64.
--
Feb 21 08:46:42 lovelace systemd[1]: Expecting device dev-mapper- safe\x2dvar.device - /dev/mapper/safe-var...
Feb 21 08:46:42 lovelace systemd[1]: Expecting device dev-
tpmrm0.device - /dev/tpmrm0...
Feb 21 08:46:42 lovelace systemd[1]: Reached target
integritysetup.target - Local Integrity Protected Volumes.
--
Feb 21 08:46:45 lovelace systemd[1]: Reached target sound.target -
Sound Card.
Feb 21 08:48:11 lovelace systemd[1]: dev-tpmrm0.device: Job dev- tpmrm0.device/start timed out.
Feb 21 08:48:11 lovelace systemd[1]: Timed out waiting for device dev-tpmrm0.device - /dev/tpmrm0.
Feb 21 08:48:11 lovelace systemd[1]: dev-tpmrm0.device: Job dev- tpmrm0.device/start failed with result 'timeout'.
Feb 21 08:48:11 lovelace systemd[1]: Reached target tpm2.target -
Trusted Platform Module.
Feb 21 08:48:11 lovelace systemd[1]: systemd-pcrextend.socket - TPM
PCR Measurements was skipped because of an unmet condition check (ConditionSecurity=measured-uki).
Feb 21 08:48:11 lovelace systemd[1]: systemd-pcrlock.socket - Make
TPM PCR Policy was skipped because of an unmet condition check (ConditionSecurity=measured-uki).
Feb 21 08:48:11 lovelace systemd[1]: systemd-pcrmachine.service - TPM
PCR Machine ID Measurement was skipped because of an unmet condition
check (ConditionSecurity=measured-uki).
Feb 21 08:48:11 lovelace systemd[1]: systemd-tpm2-setup-early.service
- Early TPM SRK Setup was skipped because of an unmet condition check (ConditionSecurity=measured-uki).
Feb 21 08:48:11 lovelace systemd[1]: Starting systemd-cryptsetup@eswap.service - Cryptography Setup for eswap...
Feb 21 08:48:11 lovelace systemd[1]: Starting systemd-cryptsetup@sda4_crypt.service - Cryptography Setup for
sda4_crypt...
Feb 21 08:48:11 lovelace systemd[1]: systemd-tpm2-setup.service - TPM
SRK Setup was skipped because of an unmet condition check (ConditionSecurity=measured-uki).
Feb 21 08:48:12 lovelace systemd-cryptsetup[1514]: Volume sda4_crypt
already active.
--
Feb 21 08:48:12 lovelace systemd[1]: Listening on systemd-
hostnamed.socket - Hostname Service Socket.
Feb 21 08:48:12 lovelace systemd[1]: systemd-pcrphase-sysinit.service
- TPM PCR Barrier (Initialization) was skipped because of an unmet
condition check (ConditionSecurity=measured-uki).
Feb 21 08:48:12 lovelace systemd[1]: Starting wtmpdb-update-
boot.service - Write boot and shutdown times into wtmpdb...
--
Feb 21 08:48:12 lovelace systemd[1]: Starting systemd-logind.service
- User Login Management...
Feb 21 08:48:12 lovelace systemd[1]: systemd-pcrphase.service - TPM
PCR Barrier (User) was skipped because of an unmet condition check (ConditionSecurity=measured-uki).
Feb 21 08:48:12 lovelace systemd[1]: Starting udisks2.service - Disk Manager...

Kernel: Linux lovelace 6.18.5+deb13-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.18.5-1~bpo13+1 (2026-02-04) x86_64 GNU/Linux

Any idea why, please ?


Thanks for your help.

--- PyGate Linux v1.5.11
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Hello,

Perhaps you will find a way to have both working properly together by
passing one or multiple option(s) to the kernel. Look at both TPM and
IOMMU options (search for these terms in the page): https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html

--- PyGate Linux v1.5.11
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)