On Wed, Aug 5, 2026 at 11:48 AM Jimmy Hon <honyuenkwun@gmail.com> wrote:
> As you mentioned here, the power domain will control the regulator. So
> please remove the regulator-always-on from the regulator.

You are right, thanks. always_on makes _regulator_disable() skip its
last-user branch, so the regulator_disable() that pd_npu issues never
reaches the hardware and the rail stays up regardless.

Dropped in v2 and retested: the three cores still probe and
regulator_summary shows vdd_npu_s0 back at a use count of zero while the
NPU is idle, so nothing pins the rail any more.

Same change commit de5b39d16318 ("arm64: dts: rockchip: Remove
workaround that prevented Turing RK1 GPU power regulator control") made
for vdd_gpu_s0. I did not add a Fixes: tag, since pd_npu had no
domain-supply before this patch and so there was nothing for always_on
to block.

Pufan