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

[Thomas Turner <tturner@lineageos.org>]

Hi Alexey,

On 07/09/2026 01:28, Alexey Klimov wrote:
> On Sat Sep 5, 2026 at 6:09 PM BST, Thomas Turner wrote:
>> 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.

>> 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 <tturner@lineageos.org>
> 
> 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 <alexey.klimov@linaro.org>
> 

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