109 lines
5.1 KiB
Markdown
109 lines
5.1 KiB
Markdown
---
|
|
description: >-
|
|
Decision to dual-install linux612 (LTS) + linux70 (stable) kernels and
|
|
migrate NVIDIA from the pinned 575xx branch to the mainline 595.71 branch
|
|
to prepare the workstation for Hyprland/Wayland.
|
|
tags:
|
|
- adr
|
|
- kernel
|
|
- nvidia
|
|
- hyprland
|
|
- wayland
|
|
last_updated: '2026-05-18'
|
|
---
|
|
|
|
# ADR 2: Kernel and NVIDIA Driver Strategy for Hyprland/Wayland
|
|
|
|
## Status
|
|
Accepted (2026-05-18)
|
|
|
|
## Context
|
|
The workstation runs Manjaro Linux on AMD Ryzen 7 2700X with an NVIDIA
|
|
GeForce GTX 1050 Ti (Pascal, GP107) driving three monitors. The next
|
|
infrastructure plan switches the desktop from KDE/X11 to Hyprland on
|
|
Wayland. Two preconditions must hold before that switch is safe:
|
|
|
|
1. **DRM/atomic and NVIDIA explicit-sync support** — Hyprland on NVIDIA
|
|
relies on driver-level explicit sync (introduced in 555.x and matured
|
|
through 575.x and 595.x). Without it, flickering and missed vblanks
|
|
are very common on Pascal+multi-monitor.
|
|
2. **Matching kernel modules** — Manjaro ships pre-built `*-nvidia`
|
|
modules pinned to a single `nvidia-utils` version. Mixing `575xx`
|
|
userspace with a kernel that only has `595.71` modules (or vice
|
|
versa) breaks the driver at the next kernel boot.
|
|
|
|
The starting point at the time of this ADR:
|
|
|
|
| Item | Version |
|
|
|---------------------------|------------------------|
|
|
| Running kernel | `linux612 6.12.77-1` |
|
|
| NVIDIA driver | `575.64.05-3` (575xx branch) |
|
|
| NVIDIA kernel module pkg | `linux612-nvidia-575xx 575.64.05-31` |
|
|
| `linux70` available in repo | `7.0.3-1` |
|
|
| `linux70-nvidia` available | `595.71.05-0.1` |
|
|
| `linux612-nvidia` (mainline) | `595.71.05-2` |
|
|
|
|
## Decision
|
|
1. **Run two kernels side by side.**
|
|
- Keep `linux612` (LTS 6.12.x) installed as the *fallback* boot entry.
|
|
- Install `linux70` (stable 7.0.x) and select it as the daily-driver
|
|
kernel via GRUB at the next reboot.
|
|
2. **Migrate NVIDIA from the `575xx` branch to mainline `595.71`** in
|
|
one atomic pacman transaction so both kernels have matching modules:
|
|
- Remove: `linux612-nvidia-575xx`, `nvidia-575xx-utils`,
|
|
`lib32-nvidia-575xx-utils`, `nvidia-575xx-settings`.
|
|
- Install: `linux612-nvidia`, `linux70-nvidia`, `nvidia-utils`,
|
|
`lib32-nvidia-utils`, `opencl-nvidia`, `nvidia-settings`.
|
|
3. **Do not change `GRUB_DEFAULT` programmatically.** The user picks
|
|
`linux70` from the GRUB menu on first boot. If `linux70` misbehaves,
|
|
the next reboot is one menu selection away from the proven LTS path.
|
|
4. **Encapsulate everything in an idempotent Ansible role**
|
|
(`ansible/roles/system-upgrade/`) that runs **before** `common`,
|
|
`dev-tools` and `maintenance`. It is invoked stand-alone with
|
|
`--tags system-upgrade` and is safe on every subsequent run.
|
|
|
|
## Rationale
|
|
- **LTS as a parachute.** 6.12 is a Linux LTS series with a multi-year
|
|
support window. Keeping it installed makes the migration reversible by
|
|
one keystroke in GRUB.
|
|
- **7.0 as the daily driver.** The 7.0 series brings the maturest
|
|
DRM/atomic-modeset and NVIDIA explicit-sync paths that Hyprland on
|
|
Pascal needs to avoid flicker on multi-monitor.
|
|
- **Mainline 595.71 over pinned 575.64.05.** Manjaro builds
|
|
`linux70-nvidia` only against `nvidia-utils=595.71.05`, so the 575xx
|
|
branch is not an option for the new kernel. Pascal (GP107) is fully
|
|
supported by 595.x, and 595.x ships the latest explicit-sync /
|
|
modesetting fixes upstream.
|
|
- **Single atomic transaction.** Removing the old branch and installing
|
|
the new one in one pacman call (with the removal list narrowed to
|
|
packages that are *actually* installed) keeps the GPU-driver window
|
|
to roughly one second of cache I/O on a local SSD.
|
|
- **Idempotent role over shell script.** Matches the existing
|
|
`common`/`dev-tools`/`maintenance` pattern, supports `--check`, and
|
|
re-running after success is a true no-op (validated by gating every
|
|
mutating task on `pacman_syu.changed or nvidia_migration.changed`).
|
|
|
|
## Consequences
|
|
- **Two kernels on `/` partition.** Roughly +120 MB for `linux70` plus
|
|
~50 MB for `linux70-nvidia`. The role pre-flight refuses to start if
|
|
free space on `/` is below 5 GiB.
|
|
- **`mhwd` profile referencing `575xx` stays as-is.** Only the
|
|
kernel-bound `linux612-nvidia-575xx` and matching userspace are
|
|
swapped; `mhwd-nvidia-575xx` stays installed so MHWD's profile
|
|
listing remains consistent. A future cleanup can switch the MHWD
|
|
profile to `video-nvidia` once `linux70` is verified.
|
|
- **Manual reboot required.** The role never reboots the machine; it
|
|
ends with a clear notice instructing the user to boot into `linux70`
|
|
from GRUB before applying the next (Hyprland) playbook.
|
|
- **Future kernel pin bumps are one-line changes** in
|
|
`ansible/vars/main.yml` (`kernel_packages` /
|
|
`nvidia_kernel_modules` lists).
|
|
|
|
## References
|
|
- Hyprland NVIDIA notes (wiki.hypr.land/Nvidia): explicit sync
|
|
available from driver ≥555 and required for tear-free Wayland.
|
|
- `docs/tech/hardware-inventory.md` (NVIDIA section).
|
|
- `ansible/roles/system-upgrade/tasks/main.yml`.
|
|
- ADR 1: `docs/adr/0001-use-ansible-for-configuration.md` — anchors the
|
|
"Ansible-first" guardrail this decision follows.
|