[PATCH v3 0/5] drm/qxl: fix shared-primary lifetime and source packing

From: Dillon Amburgey

Date: Sat Sep 26 2026 - 12:33:04 EST


QXL packs dumb framebuffers into a shared primary surface. Failed
preparation and multihead updates can leave shadow bindings inconsistent;
packing whole allocations instead of visible sources also produces
oversized surfaces and incorrect coordinates. Patch 4 establishes atomic
ownership of the shared shadow before patch 5 changes its geometry.

This series supersedes the single-patch v2 posted on September 24:
https://lore.kernel.org/r/20260925033011.12560-1-dillona@xxxxxxxxx

Changes since v2:
- Split out fixes for framebuffer pin unwinding, DirtyFB commit ordering
and error propagation, and stale disabled-head-zero monitor metadata.
- Replace BO-global shadow mutation and the shared redraw flag with
prepared atomic plane-state ownership. Include every primary plane and
CRTC in commit dependencies, replacing the lockless redraw of other
heads. This addresses the state-lifetime and redraw-flag races raised
by Sashiko AI:
https://lore.kernel.org/r/20260925034208.6B9F61F000FF@xxxxxxxxxxxxxxx
- Separate shadow lifetime from source-sized packing, retaining source
X/Y translation, packed monitor origins and clipped DirtyFB updates.
- Rebase onto mainline 6812ce4e4379 and expand regression coverage.

The series also applies and builds on drm-misc-fixes 94cf5971b1d0.
For drm-misc-next 98c7fc4219b9, patch 4 needs adaptation to the new
atomic_create_state API.

Validation:
- Each commit builds on x86 with W=1 and no new sparse diagnostics.
The final QXL driver is also compile-tested on ARM and ARM64.
- QEMU/KVM tests cover error unwinding, commit/DirtyFB ordering, shared
framebuffers, source offsets, clipped damage and concurrent modesets.
Error-path and ordering tests used test-only hooks, absent from the
series and final kernel.
- End-to-end Xorg/SPICE tests verify multihead resizing and DPMS resume
without an application repaint.

OpenAI Codex assisted development and review of the patches and regression
fixtures.

Dillon Amburgey (5):
drm/qxl: unpin the framebuffer when plane preparation fails
drm/qxl: wait for pending commits before applying DirtyFB
drm/qxl: clear the monitor configuration for disabled head zero
drm/qxl: own packed primary shadows in atomic plane state
drm/qxl: pack dumb heads from their plane source rectangles

drivers/gpu/drm/qxl/qxl_display.c | 370 ++++++++++++++++++------------
drivers/gpu/drm/qxl/qxl_draw.c | 6 +-
drivers/gpu/drm/qxl/qxl_drv.h | 5 +-
3 files changed, 229 insertions(+), 152 deletions(-)


base-commit: 6812ce4e4379ffc99c52401ec28f0d7ffbc36206
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2.43.0