marfrit
83e8eca56d
iter17 closes the 162 winding_* CTS failures from iter15's baseline by
replacing the upstream pan_nir_lower_xfb call with a panvk-specific NIR
pass (panvk_per_arch(nir_lower_xfb)) that handles per-primitive
decomposition for non-LIST topologies (LINE_STRIP, TRIANGLE_STRIP,
TRIANGLE_FAN, and the four _WITH_ADJACENCY variants).
Topology + per-instance output vertex count are threaded as new sysvals
(vs.xfb_topology + vs.xfb_output_count) so the NIR pass can dispatch
per-topology at runtime without compiling 7+ shader variants.
dEQP-VK.transform_feedback.simple.* result (133596 cases total):
iter15 baseline -> iter17
Pass: 796 958 (+162)
Fail: 243 81 (-162; resume_* by-design only)
NotSupported: 132551 132551
Fatal-skip: 6 6
Pass rate of runnable: 76.2% -> 91.7% (+15.5pp)
100% of the iter15 winding-fail cluster closed. The remaining 81 fails
are all resume_* (pause/resume XFB, by design — we advertise
transformFeedbackDraw=false).
Second-model review (janet) produced 3 findings; Findings 1+2 were
already fixed in the in-tree applied state (stale applied_state/ snapshot
read by reviewer), Finding 3 (degenerate N underflow on N<2) addressed
by gating non-LIST emission on `output_count > 0` predicate.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
mesa-panvk-bifrost
Patched Mesa libvulkan_panfrost.so exposing Bifrost-gen Mali GPUs
(Mali-G31/G52/G72/G76, PAN_ARCH 6/7) to Chromium-family browsers'
Vulkan compositor.
Result of the panvk-bifrost campaign (~/src/panvk-bifrost/),
iter9 close 2026-05-20 (technical milestone — operator-confirmed Brave
window) followed by this package as the actual delivery.
What it solves
Stock Chromium / Brave on Bifrost SBCs (PineTab2, etc.) currently dies at GL bindings init:
ERROR: ui/gl/gl_context_egl.cc:120 GLES3 is unsupported and ES version fallback is disabled
ERROR: ui/gl/init/gl_factory.cc:111 Requested GL implementation not found
ERROR: components/viz/service/main/viz_main_impl.cc:189 Exiting GPU process due to errors during initialization
This package makes Brave's Vulkan compositor path work on Bifrost, side-stepping the failing GL stack. Browser chrome and standard page rendering work.
Known limitations (not addressed)
- WebGL / WebGL2 in-page: blocked. ANGLE needs
VK_EXT_transform_feedbackto expose GLES3 contexts; PanVk-Bifrost doesn't currently support that. Sites using WebGL will degrade or refuse. - VAAPI hardware video decode: unrelated to this package — see the
libva-v4l2-request-fourierpackage for that path.
Install
# Ensure [marfrit] is in /etc/pacman.conf, then:
sudo pacman -Sy mesa-panvk-bifrost
Use
brave-vulkan # launches Brave with Vulkan
brave-vulkan https://www.example.com
brave-vulkan --your-flags-here # extra args passed through
The launcher sets:
VK_ICD_FILENAMES=/usr/lib/panvk-bifrost/icd.json(the patched driver)PAN_I_WANT_A_BROKEN_VULKAN_DRIVER=1(Mesa upstream gate)MESA_VK_VERSION_OVERRIDE=1.2(apiVersion bump for ANGLE)- Brave flags:
--use-gl=disabled --enable-features=Vulkan --use-vulkan=native --ozone-platform=x11 --no-sandbox --disable-gpu-sandbox --ignore-gpu-blocklist
What's in the package
/usr/lib/panvk-bifrost/libvulkan_panfrost.so— patched Mesa Vulkan driver (Mesa 26.0.6 + 2 sed-applied patches)/usr/lib/panvk-bifrost/icd.json— Vulkan ICD JSON pointing at the patched .so (NOT auto-loaded; only viaVK_ICD_FILENAMES)/usr/bin/brave-vulkan— launcher script
System Mesa is untouched. The stock /usr/lib/libvulkan_panfrost.so and
/usr/share/vulkan/icd.d/panfrost_icd.json continue to work for any
other Vulkan app.
Co-existence
Both stock Mesa and this package can be installed. Stock Vulkan apps
(vulkaninfo, vkcube, etc.) use the stock driver by default. Only
apps started via brave-vulkan (or with VK_ICD_FILENAMES manually
set to our path) use the patched driver.
Campaign close criterion
Per feedback_package_done_means_installable
three-point check:
- PR merged to
marfrit-packages - CI green AND
packages.reauktion.de/arch/aarch64/mesa-panvk-bifrost-*.pkg.tar.zstexists pacman -Ss mesa-panvk-bifroston a fresh consumer host (e.g. ohm afterpacman -Syufrom clean state) returns the package + brave-vulkan launches
When all three pass, panvk-bifrost iter9 closes.