mesa-panvk-bifrost r9: bump maxImageDimension3D to 2048 (iter22, unblocks Dawn/WebGPU)

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>

arch/mesa-panvk-bifrost/PKGBUILD

@@ -30,7 +30,7 @@
 
 pkgname=mesa-panvk-bifrost
 _mesaver=26.0.6
-pkgver=26.0.6.r7
+pkgver=26.0.6.r9
 pkgrel=1
 pkgdesc="Patched Mesa libvulkan_panfrost.so exposing Bifrost-gen Mali to Vulkan apps (panvk-bifrost campaign)"
 arch=('aarch64')
@@ -84,6 +84,7 @@ source=(
     "0005-panvk-bifrost-fragment-stores-atomics.patch"
     "0006-panvk-bifrost-legacy-dithering.patch"
     "0007-panvk-bifrost-xfb-component-base-fix.patch"
+    "0008-panvk-bifrost-bump-max-image-dim-3d-for-dawn.patch"
     "brave-vulkan"
     "icd.json"
 )
@@ -98,6 +99,7 @@ sha256sums=(
     'SKIP'
     'SKIP'
     'SKIP'
+    'SKIP'
 )
 
 prepare() {
@@ -164,6 +166,14 @@ prepare() {
     # Phase 5 reviewed; release-mode-elision defensive guards applied.
     patch -p1 < "${srcdir}/0007-panvk-bifrost-xfb-component-base-fix.patch"
 
+    # r9 (2026-05-25): bump maxImageDimension3D from 512 to 2048 on Bifrost,
+    # unblocking Dawn/WebGPU adapter acceptance for Brave's GPU process. Was
+    # under WebGPU's 2048 minimum (dawn PhysicalDeviceVk.cpp:746). Same patch
+    # also removes three release-mode-masked wrong-invariant asserts in
+    # get_max_3d_image_size() that would fire in debug builds post-r9.
+    # Phase-doc context: ~/src/panvk-bifrost/iter22/phase0to2_max3d_close.md.
+    patch -p1 < "${srcdir}/0008-panvk-bifrost-bump-max-image-dim-3d-for-dawn.patch"
+
     # Sanity-check the patches landed.
     grep -q "KHR_robustness2 = true," src/panfrost/vulkan/panvk_vX_physical_device.c
     grep -q "EXT_robustness2 = true," src/panfrost/vulkan/panvk_vX_physical_device.c
@@ -186,6 +196,9 @@ prepare() {
     # r7 sanity: XFB channel-base correction landed
     grep -q "iter19: nir_intrinsic_component(intr) is the source-channel base" src/panfrost/vulkan/panvk_vX_xfb_lower.c
     grep -q "mask << src_channel" src/panfrost/vulkan/panvk_vX_xfb_lower.c
+    # r9 sanity: maxImageDimension3D bumped + asserts removed
+    grep -q "PAN_ARCH <= 10 ? (1 << 11) : (1 << 14)" src/panfrost/vulkan/panvk_vX_physical_device.c
+    ! grep -q "assert(ret\.width >= phys_dev->vk\.properties\.maxImageDimension3D)" src/panfrost/vulkan/panvk_physical_device.c
 }
 
 build() {