Adds 0008-panvk-bifrost-bump-max-image-dim-3d-for-dawn.patch. Two-hunk patch:
Hunk 1: Bumps maxImageDimension3D from 512 to 2048 on Bifrost (PAN_ARCH 7..10).
Surfaced by panvk-bifrost-perf-measurement iter1 spike: Brave's WebGPU/Dawn
detects panvk-bifrost as a Vulkan adapter on Mali-G52 r1 MC1 but rejects it
because the advertised limit is below WebGPU's 2048 minimum (per
third_party/dawn/src/dawn/native/vulkan/PhysicalDeviceVk.cpp:746). This is
the actual unblock for the campaign's stated motivator — Chromium GPU
process Vulkan boot on PineTab2 / Bifrost SBCs.
Per Vulkan 1.3 spec §43.1, maxImageDimensionXD is the upper bound on any
creatable image; per-format limits MAY be smaller. On PAN_ARCH<=10 the
per-format limit caps at ~1023 per axis for RGBA8 within the 4 GB
max_img_size_B address constraint. Apps trying 2048^3 with thick formats
hit the per-format limit at image-create — per-spec behavior.
Hunk 2: Removes three asserts in get_max_3d_image_size() that encoded the
wrong invariant (per-format >= basic), opposite of what the Vulkan spec
mandates. The asserts were release-mode-masked via NDEBUG, but debug
builds would abort the first time Dawn (or any client) called
vkGetPhysicalDeviceImageFormatProperties on a 3D image format. Surfaced
by Phase 5 2nd-model review.
Verified on PineTab2 (Mali-G52 r1 MC1, PAN_ARCH 7):
- vulkaninfo: maxImageDimension3D = 2048
- Brave/Dawn: "Insufficient Vulkan limits" warning eliminated; adapter
accepted for WebGPU.
- CTS regression: dEQP-VK.api.copy_and_blit.core.image_to_image.3d_images.*
6/6 Pass (unchanged from r7 baseline).
Phase 5 (2nd-model) review: APPROVE WITH CHANGES — both changes applied
(release-mode + debug-mode assert exposure addressed by removing the
wrong-invariant asserts).
Note on numbering: r8 was attempted (KHR_depth_clamp_zero_one trim) but
abandoned mid-Phase-3 when it surfaced that 5 more post-1.3.10 KHR
extensions are advertised — surgically false-gating all of them would
risk undoing r1's KHR_robustness2 work for Chromium Dawn. Documented at
~/src/panvk-bifrost/iter21/phase0to3_close_no_ship.md.
Cross-refs:
- ~/src/panvk-bifrost/iter22/phase0to2_max3d_close.md (Phase 0-2 close)
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
marfrit
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