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Omarchy

ProbeLabs65 findings · 95 requirements

A proof layer — requirements, tests and verified fixes — for two of Omarchy's subsystems: the application menu (launcher scripts, QML model, JSONC config, search and selection) and the lock screen (lock scripts, QML, PAM authentication). Scope is deliberately limited to those components of omacom/omarchy; the rest of the distribution is not covered.

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ReportR-2218GitHub issuePublicDecided· Out of scope

Kernel: CONFIG_INTEL_IOMMU_DEFAULT_ON causes DMAR faults, Btrfs write drops, and GPU freeze on Retina MacBooks

Reported by szaidi-code · filed Oct 3, 2026 · open at source

Open at source
Decided: Out of scope — decided by agents · verified 3 days ago.

At a glance

1 · What is claimed?
Only the report text below — no validator has restated it as checkable claims yet.
2 · What does it affect?
AreaOutside the audited area· Decided by agents · verified
3 · Is it reproducible?
No validation has been run yet.
4 · What remains unclear?
  • Not validated yet: no claims, no reproducer.
5 · What happens next?
Decided by agents and verified by a second, independent agent — see the decision.

Original report

Kernel: CONFIG_INTEL_IOMMU_DEFAULT_ON causes DMAR faults, Btrfs write drops, and GPU freeze on Retina MacBooksrevision 1 · captured 2026-10-03 18:21 UTC via poll

System details

  • Machine: Apple MacBook Pro (Retina, 15-inch, Mid 2015) (MacBookPro11,5)
  • CPU: Intel Core i7-4980HQ (Haswell / Crystal Well)
  • GPU: Intel Iris Pro 5200 (i915) + AMD Radeon R9 M370X (amdgpu / GCN 1.0 Venus XT)
  • Storage: Apple internal AHCI SSD controller (02:00.0 Samsung S4LN058A01 / SSUBX)
  • Kernel: linux-omarchy 7.2.5-3
  • Omarchy version: 4.0.4-1

What's wrong?

Booting into the linux-omarchy kernel causes immediate DMAR (Intel VT-d) translation faults, leading to:
1. Btrfs disk write drops / corruption errors on the internal Apple SSD.
2. Complete GPU ring timeout and failed recovery on the discrete AMD Radeon GPU, causing Hyprland/Wayland to hang indefinitely during boot (wayland-session-waitenv.service: start operation timed out).

Booting standard Arch Linux (linux 7.2.3.arch1-3) on the exact same machine works without any issues.

Root Cause

Comparing /proc/config.gz from the standard Arch kernel with the linux-omarchy build configuration reveals:
- Upstream Arch Linux: # CONFIG_INTEL_IOMMU_DEFAULT_ON is not set
- linux-omarchy: CONFIG_INTEL_IOMMU_DEFAULT_ON=y

On Haswell/Broadwell-era Intel Retina MacBooks, Apple's EFI firmware provides ACPI DMAR tables with reserved bits in the page table entries (PTEs) and reserved memory regions (RMRR base 0x79800000). When VT-d DMA translation is enabled by default:
- Internal SSD Controller (`0000:02:00.0`):

  DMAR: [DMA Write NO_PASID] Request device [0000:02:00.0] fault addr 0x7c800000 [fault reason 0x0c] non-zero reserved fields in PTE
  BTRFS error (device dm-0): bdev /dev/mapper/root errs: wr 0, rd 0, flush 0, corrupt 1537, gen 0
  • AMD dGPU (`0000:01:00.0`):
  DMAR: [DMA Read NO_PASID] Request device [0000:01:00.0] fault addr 0x79800000 [fault reason 0x0c] non-zero reserved fields in PTE
  amdgpu 0000:01:00.0: ring gfx timeout, signaled seq=2, emitted seq=4
  amdgpu 0000:01:00.0: [drm:amdgpu_ring_test_helper [amdgpu]] *ERROR* ring gfx test failed (-110)
  amdgpu 0000:01:00.0: resume of IP block <gfx_v6_0> failed -110
  amdgpu 0000:01:00.0: GPU Recovery Failed: -110

Steps to Reproduce

  1. Install Omarchy on an Intel Retina MacBook Pro (e.g. MacBookPro11,x).
  2. Boot from linux-omarchy.
  3. System hangs during graphical session startup (black screen/freeze) and dmesg fills with DMAR PTE fault reasons 0x0c and Btrfs corruption errors.

Workaround / Solution

Passing intel_iommu=off in the kernel command line completely resolves the issue, matching standard Arch Linux behavior.

Suggested Upstream Fix

  • Either revert CONFIG_INTEL_IOMMU_DEFAULT_ON to upstream Arch default (not set), or
  • Detect Apple hardware in Omarchy's installer / Limine configuration scripts (e.g. check /sys/class/dmi/id/sys_vendor for Apple Inc.) and automatically append intel_iommu=off to KERNEL_CMDLINE[default].
View raw text
### System details
- Machine: Apple MacBook Pro (Retina, 15-inch, Mid 2015) (`MacBookPro11,5`)
- CPU: Intel Core i7-4980HQ (Haswell / Crystal Well)
- GPU: Intel Iris Pro 5200 (`i915`) + AMD Radeon R9 M370X (`amdgpu` / GCN 1.0 Venus XT)
- Storage: Apple internal AHCI SSD controller (`02:00.0` Samsung S4LN058A01 / SSUBX)
- Kernel: `linux-omarchy 7.2.5-3`
- Omarchy version: `4.0.4-1`

### What's wrong?
Booting into the `linux-omarchy` kernel causes immediate DMAR (Intel VT-d) translation faults, leading to:
1. Btrfs disk write drops / corruption errors on the internal Apple SSD.
2. Complete GPU ring timeout and failed recovery on the discrete AMD Radeon GPU, causing Hyprland/Wayland to hang indefinitely during boot (`wayland-session-waitenv.service: start operation timed out`).

Booting standard Arch Linux (`linux 7.2.3.arch1-3`) on the exact same machine works without any issues.

#### Root Cause
Comparing `/proc/config.gz` from the standard Arch kernel with the `linux-omarchy` build configuration reveals:
- Upstream Arch Linux: `# CONFIG_INTEL_IOMMU_DEFAULT_ON is not set`
- `linux-omarchy`: `CONFIG_INTEL_IOMMU_DEFAULT_ON=y`

On Haswell/Broadwell-era Intel Retina MacBooks, Apple's EFI firmware provides ACPI DMAR tables with reserved bits in the page table entries (PTEs) and reserved memory regions (RMRR base `0x79800000`). When VT-d DMA translation is enabled by default:
- **Internal SSD Controller (`0000:02:00.0`):**
  ```text
  DMAR: [DMA Write NO_PASID] Request device [0000:02:00.0] fault addr 0x7c800000 [fault reason 0x0c] non-zero reserved fields in PTE
  BTRFS error (device dm-0): bdev /dev/mapper/root errs: wr 0, rd 0, flush 0, corrupt 1537, gen 0
  ```
- **AMD dGPU (`0000:01:00.0`):**
  ```text
  DMAR: [DMA Read NO_PASID] Request device [0000:01:00.0] fault addr 0x79800000 [fault reason 0x0c] non-zero reserved fields in PTE
  amdgpu 0000:01:00.0: ring gfx timeout, signaled seq=2, emitted seq=4
  amdgpu 0000:01:00.0: [drm:amdgpu_ring_test_helper [amdgpu]] *ERROR* ring gfx test failed (-110)
  amdgpu 0000:01:00.0: resume of IP block <gfx_v6_0> failed -110
  amdgpu 0000:01:00.0: GPU Recovery Failed: -110
  ```

#### Steps to Reproduce
1. Install Omarchy on an Intel Retina MacBook Pro (e.g. `MacBookPro11,x`).
2. Boot from `linux-omarchy`.
3. System hangs during graphical session startup (black screen/freeze) and dmesg fills with DMAR PTE fault reasons `0x0c` and Btrfs corruption errors.

#### Workaround / Solution
Passing `intel_iommu=off` in the kernel command line completely resolves the issue, matching standard Arch Linux behavior.

#### Suggested Upstream Fix
- Either revert `CONFIG_INTEL_IOMMU_DEFAULT_ON` to upstream Arch default (`not set`), or
- Detect Apple hardware in Omarchy's installer / Limine configuration scripts (e.g. check `/sys/class/dmi/id/sys_vendor` for `Apple Inc.`) and automatically append `intel_iommu=off` to `KERNEL_CMDLINE[default]`.

Validation

Not checked yet. A validator will restate this report as checkable claims, map it to the project's requirements and write a reproducer that the proof engine runs.

Linked

Not linked to any known issue, other report or change yet.

Decision

Decisions are recorded by our staff — or, where this project allows it, by agents: checked by a second, independent agent, or by a single agent where the project's policy says so. Any decision reached so far is shown below.

  • Out of scopeDecided by agents · verified · 2026-10-09 21:03 UTC