On 3/12/26 7:40 AM, Pengyu Luo wrote:

On Tue, Mar 10, 2026 at 9:32 PM Konrad Dybcio
[off-list ref] wrote:

quoted

On 3/9/26 11:27 AM, Pengyu Luo wrote:

quoted

On Thu, Mar 5, 2026 6:40 PM Taniya Das [off-list ref] wrote:

quoted

From: Konrad Dybcio <redacted>

Add the GPU_CC and GX_CC (brand new! as far as we're concerned, this
is simply a separate block housing the GX GDSC) nodes, required to
power up the graphics-related hardware.

Make use of it by enabling the associated IOMMU as well. The GPU itself
needs some more work and will be enabled later.

Reviewed-by: Abel Vesa <redacted>
Signed-off-by: Konrad Dybcio <redacted>
Co-developed-by: Taniya Das <redacted>
Signed-off-by: Taniya Das <redacted>
---

Hi Taniya and Konrad, GX GDSC stuck at 'on' on my device
the raw register values are

0x3d68024: 0x00000000
0x3d68028: 0x00000000

These likely indicate that some clock or voltage rail is not accessible
at the very moment you're reading them back

It seems to be harmless. In the downstream, they are always zero too.
TB322FC:/ # devmem 0x3d68024
0x00000000
TB322FC:/ # devmem 0x3d68028
0x00000000

In [1], the commit log mentioned
The GX GDSC is modelled to aid the GMU in powering down the GPU in the
event that the GPU crashes.

quoted

GPU support for 8750 is not yet upstream (and A830 is somewhat different
vs the supported A840) - there may be something wrong in that sequence.

Indeed. Chances are that I can't enable gpu. I must reboot again and again to
match the sequence by luck, then I can enable it[2], and I must
disable register protection.(I just noticed the hack from here[3])

quoted

I heard it's in the works though, so you may be better off waiting a bit.

Glad to hear that. I am looking forward to it.

Slightly off-topic, do you know if anyone is working on wcn786x/wcn7880,
sm8750 QRD SKU2 V8 Power Grid uses this.

I don't know. You can try asking on ath12k@lists.infradead.org

Konrad