iter1 minimal compute probe — captured 2026-05-19 on ohm
(PineTab2 v2.0, RK3566, Mali-G52 r1 MC1, Mesa 26.0.6, kernel 7.0.0-danctnix1-6)

Source: panvk-bifrost/iter1/{probe_compute.c, probe_compute.comp, Makefile}
Deployed to: /tmp/panvk-iter1/
Build: clean (no warnings with -Wall -Wextra)
Binary: 260592 bytes
SPV:    560 bytes

===== RUN #1 (no validation layer) =====
$ PAN_I_WANT_A_BROKEN_VULKAN_DRIVER=1 ./probe_compute

[step] vkCreateInstance
[step] vkEnumeratePhysicalDevices
WARNING: panvk is not a conformant Vulkan implementation, testing use only.
[info] gpu='Mali-G52 r1 MC1' apiVersion=1.0.335 driverVersion=109051910
[step] vkGetPhysicalDeviceQueueFamilyProperties
[info] using queue family 0 (flags=0x7)
[step] vkCreateDevice
[step] vkCreateBuffer (storage, host-visible)
[info] buffer memReq size=64 alignment=64 typeBits=0x7
[step] vkAllocateMemory
[step] vkMapMemory (pre-write 0xDEADBEEF sentinel)
[step] vkCreateDescriptorSetLayout
[step] vkCreateDescriptorPool
[step] vkAllocateDescriptorSets
[step] vkUpdateDescriptorSets
[step] vkCreateShaderModule (from probe_compute.spv)
[step] vkCreatePipelineLayout
[step] vkCreateComputePipelines
[step] vkCreateCommandPool
[step] vkAllocateCommandBuffers
[step] vkBeginCommandBuffer + record dispatch
[step] vkCreateFence
[step] vkQueueSubmit
[step] vkWaitForFences (5s timeout)
[step] vkInvalidateMappedMemoryRanges + readback
[info] buffer[0] = 0xcafebabe (expected 0xcafebabe)
[PASS] PanVk-Bifrost compute dispatch wrote the expected pattern.
===== RC=0 =====

===== RUN #2 (VK_LAYER_KHRONOS_validation enabled) =====
$ PAN_I_WANT_A_BROKEN_VULKAN_DRIVER=1 \
  VK_INSTANCE_LAYERS=VK_LAYER_KHRONOS_validation ./probe_compute

[same step trace as above]
[info] buffer[0] = 0xcafebabe (expected 0xcafebabe)
[PASS] PanVk-Bifrost compute dispatch wrote the expected pattern.
===== RC=0 =====

No validation-layer warnings or errors emitted. (vkCreateInstance succeeded
with the layer string in VK_INSTANCE_LAYERS, which implies the loader found
and activated the layer; otherwise it would return VK_ERROR_LAYER_NOT_PRESENT.)

===== STABILITY: 5 consecutive reruns =====
$ for i in 1 2 3 4 5; do PAN_I_WANT_A_BROKEN_VULKAN_DRIVER=1 ./probe_compute; done

[info] buffer[0] = 0xcafebabe (expected 0xcafebabe)
[PASS] PanVk-Bifrost compute dispatch wrote the expected pattern.
[info] buffer[0] = 0xcafebabe (expected 0xcafebabe)
[PASS] PanVk-Bifrost compute dispatch wrote the expected pattern.
[info] buffer[0] = 0xcafebabe (expected 0xcafebabe)
[PASS] PanVk-Bifrost compute dispatch wrote the expected pattern.
[info] buffer[0] = 0xcafebabe (expected 0xcafebabe)
[PASS] PanVk-Bifrost compute dispatch wrote the expected pattern.
[info] buffer[0] = 0xcafebabe (expected 0xcafebabe)
[PASS] PanVk-Bifrost compute dispatch wrote the expected pattern.

6/6 runs PASS.

===== DMESG (panfrost-related, full boot tail) =====
[    5.331157] panfrost fde60000.gpu: clock rate = 594000000
[    5.331201] panfrost fde60000.gpu: bus_clock rate = 500000000
[    5.336259] panfrost fde60000.gpu: [drm:panfrost_devfreq_init [panfrost]] Failed to register cooling device
[    5.336430] panfrost fde60000.gpu: mali-g52 id 0x7402 major 0x1 minor 0x0 status 0x0
[    5.336443] panfrost fde60000.gpu: features: 00000000,00000df7, issues: 00000000,00000400
[    5.336450] panfrost fde60000.gpu: Features: L2:0x07110206 Shader:0x00000002 Tiler:0x00000209 Mem:0x1 MMU:0x00002823 AS:0xff JS:0x7
[    5.336458] panfrost fde60000.gpu: shader_present=0x1 l2_present=0x1
[    5.344566] panfrost fde60000.gpu: [drm] Using Transparent Hugepage
[    5.347277] [drm] Initialized panfrost 1.6.0 for fde60000.gpu on minor 1

No GPU faults, no MMU faults, no kernel-side panfrost warnings after running
the probe 6 times.