Re: [PATCH v3 2/2] arm64: dts: exynos: Add GPU/Mali Bifrost node to Exynos850

Hi Alexey,

On 07/09/2026 01:28, Alexey Klimov wrote:

On Sat Sep 5, 2026 at 6:09 PM BST, Thomas Turner wrote:

quoted

Add nodes for GPU (Mali Bifrost) to Exynos850. Does not provide support
for temperature throttling, DVFS, power domains, governor support,

One of the sensors exposed via ACPM is "linked" to the GPU/G3D as far as
I know. The driver part was sent already and three sensors work there
(two cpu clusters and GPU).

I've never tested yet the DVFS of G3D via ACPM. Maybe it is worth a try
on A21s. But it should work the same way as clusters clocks.

I have had a little look at your ACPM stuff currently staged, looks like 
some really good work, would be cool to see if we could get dvfs working 
via acpm at some point :D.

quoted

boosting and voltage control. Once PMIC is properly implemented, support
will hopefully increase. However, the panfrost driver probes, the
Mali-G52 GPU initializes and the core clock is set-up.

Testing for this patch was done on a device not currently supported by
linux, the Galaxy A21s. After enabling this node for that device
locally, I was able to test and confirm basic GPU functionality. As of
now, this patch has no users which have tested GPU capabilities and so
the node has been set to "disabled".

Here are some logs I pulled:

panfrost 11500000.gpu: clock rate = 377000000
panfrost 11500000.gpu: mali-g52 id 0x7212 major 0x0 minor 0x0 status 0x0
panfrost 11500000.gpu: features: 00000000,00000df7, issues: 00000000,00000400
panfrost 11500000.gpu: Features: L2:0x07100206 Shader:0x00000000 Tiler:0x00000809 Mem:0x1 MMU:0x00002830 AS:0xff JS:0x7
panfrost 11500000.gpu: shader_present=0x1 l2_present=0x1
panfrost 11500000.gpu: [drm] Using Transparent Hugepage
[drm] Initialized panfrost 1.6.0 for 11500000.gpu on minor 0

OpenGL core profile vendor: Mesa
OpenGL core profile renderer: Mali-G52 MC1 (Panfrost)
OpenGL core profile version: 3.1 (Core Profile) Mesa 26.1.6
OpenGL core profile shading language version: 1.40
OpenGL compatibility profile vendor: Mesa
OpenGL compatibility profile renderer: Mali-G52 MC1 (Panfrost)
OpenGL compatibility profile version: 3.1 (Core Profile) Mesa 26.1.6
OpenGL compatibility profile shading language version: 1.40
OpenGL ES profile vendor: Mesa
OpenGL ES profile renderer: Mali-G52 MC1 (Panfrost)
OpenGL ES profile version: OpenGL ES 3.1 Mesa 26.1.6
OpenGL ES profile shading language version: OpenGL ES GLSL ES 3.10

Signed-off-by: Thomas Turner <redacted>

So, I've got A21s and installed pmOS to test all that.
My logs are slightly different but graphics is definitely alive:
[    0.200787] [drm] Initialized simpledrm 1.0.0 for fa000000.framebuffer on minor 0
[    0.215130] Console: switching to colour frame buffer device 90x100
[    0.225540] simple-framebuffer fa000000.framebuffer: [drm] fb0: simpledrmdrmfb frame buffer device
[    0.226134] panfrost 11500000.gpu: clock rate = 377000000
[    0.230960] panfrost 11500000.gpu: mali-g52 id 0x7212 major 0x0 minor 0x0 status 0x0
[    0.230981] panfrost 11500000.gpu: features: 00000000,00000df7, issues: 00000000,00000400
[    0.230991] panfrost 11500000.gpu: Features: L2:0x07100206 Shader:0x00000000 Tiler:0x00000809 Mem:0x1 MMU:0x00002830 AS:0xff JS:0x7
[    0.231002] panfrost 11500000.gpu: shader_present=0x1 l2_present=0x1
[    0.232329] panfrost 11500000.gpu: [drm] Using Transparent Hugepage
[    0.232726] [drm] Initialized panfrost 1.6.0 for 11500000.gpu on minor 1

Also, when this is applied with status="okay" on Winlink board then
panfrost itself seems to be alive and drm initialises despite missing
regulator as indicated in my other email in v2 of this series, hence:

Alright cool, just for the records we have tested this series on the 
A21s both with and without proper regulators and GPU seems to work fine 
with dummy regs.

Reviewed-and-tested-by: Alexey Klimov [off-list ref]

Cheers, will give this version a few days to stew then I will add this 
onto v4.

Thanks for working on this.
Best regareds,
Alexey

I really appreciate all of the testing and insight you have provided in 
the last few messages, now that we have Samsung E850s booting I hope to 
expand support across the whole SoC :D.

Cheers,
Tom