godot: Vulkan: Editor freezes when system wakes up from sleep

Given how this isn’t a Godot-specific issue and large sweeping changes are required to support suspend on Linux, it’s fair to document this for now.

This definitely seems to be a wider problem than Godot. I booted up Valheim on Pop! OS and put my computer into sleep mode. The Vulkan version of Valheim behaved just like Godot 4 (entire window stopped rendering), whereas OpenGL version of Valheim behaved more like Godot 3 (2D UI continued to render, but 3D meshes were completely black)

Also since I don’t think it was mentioned in this thread yet: this problem affects not just the editor but any games made with Godot as well

Regarding NVIDIA GPUs, it seems this is currently a limitation of the driver. There is an experimental option you can enable to copy VRAM to RAM before suspending: https://wiki.archlinux.org/title/NVIDIA/Tips_and_tricks#Preserve_video_memory_after_suspend

This also explains why the issue could only be reproduced on NVIDIA GPUs so far.

Can anyone try this and see if it works?

I am also experiencing this issue with the recently released godot 4 alpha build. So far, this issue has happened every time I have slept/resumed my system.

Godot Engine v4.0.alpha1.official.31a7ddbf8 Linux 5.15.16-1-MANJARO x86_64; GNOME Shell 41.3 Vulkan API 1.2.202 - Using Vulkan Device #0: NVIDIA - NVIDIA GeForce MX150

Godot Engine v3.4.2.stable.official.45eaa2daf does not have the same problem for me and I haven’t noticed any material problems like the one @hmans mentioned.

As @fwsGonzo said, the editor still responds to mouse clicks, but the window shows a ghost of the last rendered content. Also, a project does not need to be opened (stay at project manager window) before sleeping/resuming breaks godot’s window rendering.

Running from the terminal shows lots of these errors whenever a re-render event is triggered (such as resizing the window or hovering over components inside):

ERROR: Condition "err" is true. Returning: ERR_CANT_CREATE
   at: swap_buffers (drivers/vulkan/vulkan_context.cpp:1956)
ERROR: Vulkan: Did not create swapchain successfully.
   at: prepare_buffers (drivers/vulkan/vulkan_context.cpp:1880)

I also saw this error in one of my tests, but it may not be related.

ERROR: Condition "!material" is true.
   at: material_set_shader (servers/rendering/renderer_rd/renderer_storage_rd.cpp:1570)

Lspci shows:

01:00.0 3D controller: NVIDIA Corporation GP108M [GeForce MX150] (rev a1)
        Subsystem: Lenovo ThinkPad T480
        Flags: bus master, fast devsel, latency 0, IRQ 159
        Memory at dc000000 (32-bit, non-prefetchable) [size=16M]
        Memory at 80000000 (64-bit, prefetchable) [size=256M]
        Memory at 90000000 (64-bit, prefetchable) [size=32M]
        I/O ports at d000 [size=128]
        Capabilities: [60] Power Management version 3
        Capabilities: [68] MSI: Enable+ Count=1/1 Maskable- 64bit+
        Capabilities: [78] Express Endpoint, MSI 00
        Capabilities: [100] Virtual Channel
        Capabilities: [250] Latency Tolerance Reporting
        Capabilities: [258] L1 PM Substates
        Capabilities: [128] Power Budgeting <?>
        Capabilities: [420] Advanced Error Reporting
        Capabilities: [600] Vendor Specific Information: ID=0001 Rev=1 Len=024 <?>
        Capabilities: [900] Secondary PCI Express
        Kernel driver in use: nvidia
        Kernel modules: nouveau, nvidia_drm, nvidia

See also https://github.com/godotengine/godot/issues/41559.

@hmans Can you reproduce this with Godot 3.3.3?

Note that in general, NVIDIA + suspend on Linux is not very reliable. Open source drivers generally fare better here, but there are no viable open source drivers available for Maxwell 2 and newer GPUs due to NVIDIA’s signed firmware requirement.