Edit: Just realized I'm a doofus and the GCN 2 is actually Sea Islands. So everywhere I said Southern Islands I really meant Sea Islands.

Hi guys, longtime Slackware-current user here trying out NetBSD for the first time. A couple months ago I bought a pile of old Wyse-5020 thin clients on the cheap off of eBay. These machines are actually pretty beefy as thin clients go, build around an AMD quad core 1.5GHz Kabini SoC with 4GB of DDR3 and a 16GB SATA DOM.

The SoC is a GX-415GA which is the "Embedded" segment variant of Kabini. I figured these would be good for test driving some OSes that I've been interested in so that's what I've been trying lately. NetBSD in particular is one I've wanted to take for an extensive test drive for some time now.

I installed NetBSD-9.1 on there and it was very easy. Initially I had it set up for UEFI and it would try to initialize the graphics chip on startup but fail with errors related to VCE (which I believe is the hardware video support) IIRC. Same in UEFI/Legacy "Both" mode. However, in Legacy mode everything seems to initialize just fine. Here is the relevant output from dmesg

[     8.835910] kern info: [drm] initializing kernel modesetting (KABINI 0x1002:0x9833 0x1002:0x0123).
[     8.835910] kern info: [drm] register mmio base: 0xf0900000
[     8.835910] kern info: [drm] register mmio size: 262144
[     8.835910] kern info: [drm] doorbell mmio base: 0xF0000000
[     8.835910] kern info: [drm] doorbell mmio size: 8388608
[     8.835910] kern info: ATOM BIOS: AMD
[     8.835910] radeon0: info: VRAM: 512M 0x0000000000000000 - 0x000000001FFFFFFF (512M used)
[     8.835910] radeon0: info: GTT: 2048M 0x0000000020000000 - 0x000000009FFFFFFF
[     8.835910] kern info: [drm] Detected VRAM RAM=200M, BAR=256M
[     8.835910] kern info: [drm] RAM width 128bits DDR
[     8.835910] Zone  kernel: Available graphics memory: 970712 kiB
[     8.835910] kern info: [drm] radeon: 512M of VRAM memory ready
[     8.835910] kern info: [drm] radeon: 2048M of GTT memory ready.
[     8.835910] kern info: [drm] Loading kabini Microcode
[     8.845914] kern info: [drm] Internal thermal controller without fan control
[     8.845914] kern info: [drm] radeon: dpm initialized
[     8.845914] kern info: [drm] Found VCE firmware/feedback version 40.2.2 / 15!
[     8.845914] kern info: [drm] GART: num cpu pages 524288, num gpu pages 524288
[     8.885929] kern info: [drm] PCIE GART of 2048M enabled (table at 0x0000000000324000).
[     8.885929] radeon0: info: WB enabled            
[     8.885929] radeon0: info: fence driver on ring 0 use gpu addr 0x0000000020000c00 and cpu addr 0x0xfffff4c6f7fa4c00
[     8.885929] radeon0: info: fence driver on ring 1 use gpu addr 0x0000000020000c04 and cpu addr 0x0xfffff4c6f7fa4c04
[     8.885929] radeon0: info: fence driver on ring 2 use gpu addr 0x0000000020000c08 and cpu addr 0x0xfffff4c6f7fa4c08
[     8.885929] radeon0: info: fence driver on ring 3 use gpu addr 0x0000000020000c0c and cpu addr 0x0xfffff4c6f7fa4c0c
[     8.885929] radeon0: info: fence driver on ring 4 use gpu addr 0x0000000020000c10 and cpu addr 0x0xfffff4c6f7fa4c10
[     8.885929] radeon0: info: fence driver on ring 5 use gpu addr 0x0000000000076c98 and cpu addr 0x0xffffd4005e816c98
[     8.885929] radeon0: info: fence driver on ring 6 use gpu addr 0x0000000020000c18 and cpu addr 0x0xfffff4c6f7fa4c18
[     8.885929] radeon0: info: fence driver on ring 7 use gpu addr 0x0000000020000c1c and cpu addr 0x0xfffff4c6f7fa4c1c
[     8.885929] kern info: [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[     8.885929] kern info: [drm] Driver supports precise vblank timestamp query.
[     8.885929] radeon0: interrupting at ioapic1 pin 20 (radeon0)
[     8.885929] kern info: [drm] radeon: irq initialized.
[     8.885929] kern info: [drm] ring test on 0 succeeded in 3 usecs
[     8.885929] kern info: [drm] ring test on 1 succeeded in 3 usecs
[     8.885929] kern info: [drm] ring test on 2 succeeded in 3 usecs
[     8.885929] kern info: [drm] ring test on 3 succeeded in 4 usecs
[     8.885929] kern info: [drm] ring test on 4 succeeded in 4 usecs
[     8.935942] kern info: [drm] ring test on 5 succeeded in 1 usecs
[     8.955949] kern info: [drm] UVD initialized successfully.
[     9.065987] kern info: [drm] ring test on 6 succeeded in 16 usecs
[     9.065987] kern info: [drm] ring test on 7 succeeded in 3 usecs
[     9.065987] kern info: [drm] VCE initialized successfully.
[     9.065987] kern info: [drm] ib test on ring 0 succeeded in 0 usecs
[     9.566161] kern info: [drm] ib test on ring 1 succeeded in 0 usecs
[    10.066330] kern info: [drm] ib test on ring 2 succeeded in 0 usecs
[    10.066330] kern info: [drm] ib test on ring 3 succeeded in 0 usecs
[    10.066330] kern info: [drm] ib test on ring 4 succeeded in 0 usecs
[    10.586662] kern info: [drm] ib test on ring 5 succeeded
[    10.606668] kern info: [drm] ib test on ring 6 succeeded
[    10.606668] kern info: [drm] ib test on ring 7 succeeded
[    10.606668] kern info: [drm] Radeon Display Connectors
[    10.606668] kern info: [drm] Connector 0:
[    10.606668] kern info: [drm]   DP-1
[    10.606668] kern info: [drm]   HPD2
[    10.606668] kern info: [drm]   DDC: 0x6540 0x6540 0x6544 0x6544 0x6548 0x6548 0x654c 0x654c
[    10.606668] kern info: [drm]   Encoders:
[    10.606668] kern info: [drm]     DFP1: INTERNAL_UNIPHY
[    10.606668] kern info: [drm] Connector 1:
[    10.606668] kern info: [drm]   DVI-D-1
[    10.606668] kern info: [drm]   HPD1
[    10.606668] kern info: [drm]   DDC: 0x6530 0x6530 0x6534 0x6534 0x6538 0x6538 0x653c 0x653c
[    10.606668] kern info: [drm]   Encoders:
[    10.606668] kern info: [drm]     DFP2: INTERNAL_UNIPHY
[    10.606668] kern info: [drm] Connector 2:
[    10.606668] kern info: [drm]   VGA-1
[    10.606668] kern info: [drm]   DDC: 0x65c0 0x65c0 0x65c4 0x65c4 0x65c8 0x65c8 0x65cc 0x65cc
[    10.606668] kern info: [drm]   Encoders:
[    10.606668] kern info: [drm]     CRT1: INTERNAL_KLDSCP_DAC1
[    10.676692] radeondrmkmsfb0 at radeon0
[    10.686695] radeondrmkmsfb0: framebuffer at 0xffffd4005f2ac000, size 3840x2160, depth 32, stride 15360
[    10.696699] hdafg0:   ELD version=0x2,len=172,edid=0x0,port=0xffffffff80249944,vendor=0x0020,product=0x0000
[    10.696699] hdafg0:   Monitor = ''
[    10.696699] hdafg0:   SAD id=0,format=0,channels=1,rate=0x00,maxbitrate=0
[    10.696699] hdafg0:   SAD id=1,format=0,channels=1,rate=0x60,maxbitrate=168000
[    10.696699] hdafg0:   SAD id=2,format=5,channels=4,rate=0x5e,maxbitrate=0
[    10.696699] hdafg0:   SAD id=3,format=10,channels=5,rate=0xff,maxbitrate=2040000
[    10.696699] hdafg0:   SAD id=4,format=0,channels=1,rate=0x00,maxbitrate=0
[    10.696699] hdafg0:   SAD id=5,format=0,channels=1,rate=0x00,maxbitrate=0
[    10.696699] hdafg0:   SAD id=6,format=0,channels=1,rate=0x00,maxbitrate=0
[    10.696699] hdafg0:   SAD id=7,format=0,channels=1,rate=0x00,maxbitrate=0
[    10.696699] hdafg0:   SAD id=8,format=0,channels=1,rate=0x00,maxbitrate=0
[    10.696699] hdafg0:   SAD id=9,format=0,channels=1,rate=0x00,maxbitrate=0
[    10.696699] hdafg0:   SAD id=10,format=0,channels=1,rate=0x00,maxbitrate=0
[    10.696699] hdafg0:   SAD id=11,format=0,channels=1,rate=0x00,maxbitrate=0
[    10.696699] hdafg0:   SAD id=12,format=0,channels=1,rate=0x00,maxbitrate=0
[    10.786729] wsdisplay0 at radeondrmkmsfb0 kbdmux 1: console (default, vt100 emulation), using wskbd0

So great I'm thinking! Kernel driver seems to support this GPU and I get a /dev/dri/card0 device. On to Xorg! I installed my wm of choice (Window Maker but I don't think it's particularly relevant to the issue of getting the GPU working) and fired up X. It gives me a desktop with no issues and at the "best" supported resolution to boot (4K@30Hz though IMO 30Hz is useless and I always change to 1920x1080@60Hz)!

However, I can tell right away that it's not accelerated by the way the windows tear when moving them around and the just slight sluggishness of the whole thing. I know that this is usable, but this is something that bugs the heck out of me on a desktop machine and is a bit of a dealbreaker, reminds me of the difference between playing an NES on an old CRT vs a newer LCD TV. Some people don't notice enough to care or just get used to it, but there is definitely a difference in feel. I'd be happy to post the full Xorg log if necessary but the short of it is that it uses the radeon driver which seems correct (and lists KABINI clearly near the end of the long list of supported chips) but it seems like perhaps some other library in the stack doesn't have the necessary support. I think the relevant output is this:

[ 41673.160] (II) Loading sub module "dri2"
[ 41673.160] (II) LoadModule: "dri2"
[ 41673.160] (II) Module "dri2" already built-in
[ 41673.226] (II) Loading sub module "glamoregl"
[ 41673.226] (II) LoadModule: "glamoregl"
[ 41673.229] (II) Loading /usr/X11R7/lib/modules/libglamoregl.so
[ 41673.230] (II) Module glamoregl: vendor="X.Org Foundation"
[ 41673.230]    compiled for 1.20.5, module version = 1.0.1
[ 41673.230]    ABI class: X.Org ANSI C Emulation, version 0.4
[ 41673.300] (II) RADEON(0): Refusing to try glamor on llvmpipe
[ 41673.302] (EE) RADEON(0): glamor detected, failed to initialize EGL.
...
[ 41673.433] (WW) RADEON(0): Direct rendering disabled
...
[ 41673.463] (II) Initializing extension GLX
[ 41673.464] (II) AIGLX: Screen 0 is not DRI2 capable
[ 41673.478] (II) IGLX: Loaded and initialized swrast
[ 41673.478] (II) GLX: Initialized DRISWRAST GL provider for screen 0
[ 41673.478] (II) Initializing extension XFree86-VidModeExtension
[ 41673.479] (II) Initializing extension XFree86-DGA
[ 41673.480] (II) Initializing extension XFree86-DRI
[ 41673.480] (II) Initializing extension DRI2

If I use X -configure to generate a config file, it sets the driver to amdgpu instead, which surprised me as I thought it would detect it the same way as it does when you start X with no config file. It also seems to incorrectly detect the sound card device of the GPU as another graphics card, so I deleted that Device and its associated Screen and try to launch X with those settings. The X -configure command will output this error when it runs:

(II) AMDGPU(0): [KMS] Kernel modesetting enabled.
amdgpu_device_initialize: DRM version is 2.43.0 but this driver is only compatible with 3.x.x.
(II) AMDGPU(1): [KMS] drm report modesetting isn't supported.

I think the AMDGPU(1) is talking about the misidentified sound portion but the other part seems relevant. I suspect it's because I don't actually have the amdgpu module set up on NetBSD? Anyway, trying to launch X with this configuration fails.

Taking this configuration and changing the driver to radeon does launch, but is unaccelerated just like the no config. Changing the driver to modesetting also launches, but unaccelerated. In both cases it produces the same error about "Refusing to try glamor on llvmpipe" and "glamor initialization failed".

The GPU is a GCN 2 design and identifies itself as "HD 8330E". I think it's a bit of an oddball GPU in that it is supported by both the radeon kernel module and the amdgpu kernel module on Linux. It defaults to radeon but I always switch it to use amdgpu with the options (one disable Southern Islands on the radeon module and one enables it on the amdgpu module) because it allows for Vulkan support. Other than Vulkan it should work just fine. amdgpu support for Southern Islands is currently listed as experimental but I haven't had any issues on Linux.

I have tried this same machine on FreeBSD-12.1 and was able to get hardware accelerated X rather easily by adding a line to load their amdgpu to rc.conf. I also tried their radeonkms driver just to see and it didn't log errors when it loaded but the console stayed at VGA resolution and X was unaccelerated. It might be that I just need to configure something to make that work but I didn't bother since amdgpu is working just fine there.

So I guess I feel like I'm at the point where it would be extremely helpful to just ask and see if someone can point me in the correct direction of where to go next with this. From what I gather, amdgpu is in NetBSD-current but I'm not sure how new it is. I looked in the NetBSD source in github and it seems like it hasn't been touched in quite some time (1-2 years?) but I know NetBSD is actually using CVS for source control and I'm not sure how well the commit history translates over to git. In any case, I feel like the kernel driver is working just fine. I did make a USB boot stick for NetBSD-current but it hangs when booting and I haven't attempted to resolve that issue.

I had the idea to try glmark2 as I recall it can be built to run directly on dri without X but the one in pkgin doesn't seem to be built with that support and I haven't tried compiling it myself yet, but that may be a good way to test if the kernel module is working properly.

From reading around it sounds like the modular xorg is a bit more up to date but I'm not sure how to actually install it. The "how to install modular xorg" starts with assuming you didn't install the X11 sets but as far as I can tell doesn't tell you how to remove them if you did. It's not clear to me if it's just some trivial command to remove a set from the base system or if it would be a tedious manual task. I'd rather not have to reinstall the OS if someone with more experience can tell that that's unlikely to be the issue anyway.

Appreciate any help I can get and looking forward to contributing to the community!