[Bug 2169505] [NEW] NVIDIA dGPU never enters RTD3 on kernel 7.3.0; works on 7.0.0

You have been subscribed to a public bug: Dell XPS 15 9530, hybrid Intel Iris Xe + RTX 4070 Laptop (AD106M), Ubuntu 26.10, nvidia 615.71.09 (open, from the archive), GNOME/Wayland, PRIME on-demand, display on the iGPU. Same driver, same DKMS build, same config, only the kernel differs: 7.3.0-8-generic: /proc/driver/nvidia/gpus/0000:01:00.0/power Runtime D3 status: Not supported Video Memory: Active power/runtime_status = active power/runtime_suspended_time = 0 (across full uptime, every boot) 7.0.0-38-generic: /proc/driver/nvidia/gpus/0000:01:00.0/power Runtime D3 status: Enabled (fine-grained) Video Memory: Off power/runtime_status = suspended power/runtime_suspended_time = 24769 Every documented RTD3 requirement is satisfied on both kernels: - Ada GPU (newer than the Turing minimum) - CONFIG_PM=y, CONFIG_PCIE_PME=y - ACPI _PR3 present: \_SB_.PC00.PEG1.PG01 "New power resource"; power_resources_D3hot present on the parent bridge 0000:00:01.0 - d3cold_allowed=1 on bridge and GPU - NVreg_DynamicPowerManagement=0x02, set by Ubuntu's own /usr/lib/modprobe.d/nvidia-runtimepm.conf - no displays on the dGPU (no card2-* connectors) - platform ships a dedicated RTD3 ACPI table: ACPI: SSDT (v02 DELL DellRtd3 00001000 INTL 20200717) So on 7.3 the driver declines RTD3 on a platform that meets every requirement and that demonstrably works on 7.0. Impact: the dGPU is pinned in D0 permanently — constant idle power draw and heat on battery. Likely the same regression as CachyOS/linux-cachyos#1053, where 7.2.6 reported "Enabled (fine-grained)" and 7.3.0-rc3 reported "Not supported". That reporter believed it was CachyOS-specific; this reproduces on Ubuntu's own 7.3.0-8-generic, so it is not. Combining both data points puts the regression window at 7.2.6 -> 7.3.0-rc3. Not reproducible on 7.0.0-38-generic. I have no 7.1/7.2 kernels installed to narrow it further locally, but can test builds on request. ** Affects: linux (Ubuntu) Importance: Undecided Status: New -- NVIDIA dGPU never enters RTD3 on kernel 7.3.0; works on 7.0.0 https://bugs.launchpad.net/bugs/2169505 You received this bug notification because you are subscribed to linux in Ubuntu.