[Bug Report] Ubuntu 26.04: Suspend/Resume Black Screen on ASUS Vivobook M6500QF (AMD Cezanne + NVIDIA RTX 2050 Mobile, Driver 595.99.02, Kernel 7.0)

[Juerg Haefliger]

On Sun, 11 Oct 2026 11:58:40 +0530
Nitin Chandra <nitinchandra.dev at gmail.com> wrote:

> Black screen on suspend/resume on ASUS Vivobook M6500QF (AMD Cezanne + RTX
> 2050
>   │ Mobile, driver 595.99.02, kernel 7.0): PCIe D3hot->D0 link failure and
> nvidia-
>   │ sleep.sh VT63 entrapment
> 
>  System Information:
> 
>     - Laptop: ASUS Vivobook M6500QF_M6500QF (BIOS M6500QF.303)
> 
>     - OS: Ubuntu 26.04.1 LTS (x86_64)
> 
>     - Kernel: 7.0.0-38-generic
> 
>     - Display Session: Wayland (GNOME Shell)
> 
>     - Integrated GPU: AMD Cezanne Radeon Vega Series [1002:1638] (rev c5),
> amdgpu driver
>   (eDP-1)
> 
>     - Discrete GPU: NVIDIA GA107 [GeForce RTX 2050 Mobile] [10de:25ad] (rev
> a1),
>   Subsystem 1043:1ab3
> 
>     - Upstream PCIe Bridge: AMD Renoir/Cezanne PCIe GPP Bridge [1022:1633]
> @ 0000:00:01.
>   1
> 
>     - Driver: nvidia-driver-595-open (595.99.02-0ubuntu0.26.04.1)
> 
>     - Sleep Mode: [s2idle]
> 
> 
> 
>     Description of the problem:
> 
>     On Ubuntu 26.04 with kernel 7.0.0-38 and NVIDIA driver 595.99.02,
> suspending the
>   system results in an unrecoverable black screen upon wake. Investigation
> of journalctl
>   and kernel traces reveals two distinct issues:
> 
> 
> 
>     1. Low-level PCIe Power State Failure:
> 
>     Upon resume from s2idle, the kernel PCI subsystem attempts to
> transition the NVIDIA
>   GPU from D3hot to D0:
> 
>     "kernel: nvidia 0000:01:00.0: Unable to change power state from D3hot
> to D0, device
>   inaccessible"
> 
>     The upstream AMD root port (0000:00:01.1) fails link training or drops
> power to the
>   slot, causing config reads to return 0xFFFF. The AMD iGPU resumes cleanly
> ("SMU is
>   resumed successfully"), and the rest of userspace (NetworkManager,
> chrony, systemd)
>   remains alive in the background. The system is NOT frozen.
> 
> 
> 
>     2. Driver / Userspace Deadlock & VT63 Entrapment:
> 
>     - Before sleep, /usr/bin/nvidia-sleep.sh forces a virtual terminal
> switch: "chvt 63".
>     - On resume, /usr/lib/systemd/system-sleep/nvidia executes:
> 
>       "/usr/bin/nvidia-sleep.sh resume" -> "echo resume >
> /proc/driver/nvidia/suspend"
>     - In the kernel, nv_set_system_power_state() acquires
> down_write(&nv_system_pm_lock).
>     - Because the PCIe link is inaccessible, BAR0 MMIO reads return 0x0,
> entering an
>   infinite loop:
> 
>       "kernel: NVRM: kbusVerifyBar2_GM107: MMUTest BAR0 window offset
> 0x70e000 returned
>   garbage 0x0"
> 
>     - Because this kernel call never returns, line 57 of nvidia-sleep.sh
> ("RestoreVT" /
>   chvt) is never executed. The display remains permanently trapped on empty
> VT 63.
>     - After 180 seconds, systemd-suspend attempts to kill nvidia-sleep.sh
> with SIGKILL,
>   but it cannot exit because it is stuck in kernel space holding
> nv_system_pm_lock.
>   Other processes touching NVIDIA (e.g., nv_queue, GNOME Shell) block on
> the rw-
>   semaphore:
> 
>       "kernel: INFO: task nv_queue:1044 <writer> blocked on an rw-semaphore
> likely owned
>   by task nvidia-sleep.sh:15431 <writer>"
> 
> 
> 
>     3. Incompatibility with direct PM / rtcwake:
> 
>     Ubuntu's default /etc/modprobe.d/nvidia-graphics-drivers-kms.conf
> configures:
>       options nvidia NVreg_PreserveVideoMemoryAllocations=1
> 
>     without enabling NVreg_UseKernelSuspendNotifiers=1.
> 
>     Direct kernel suspends or tests (e.g. `rtcwake -m mem`) bypass systemd
> services and
>   immediately abort with error -5 (-EIO):
>       "NVRM: GPU 0000:01:00.0: PreserveVideoMemoryAllocations module
> parameter is set.
>   System Power Management attempted without driver procfs suspend
> interface."
>       "nvidia 0000:01:00.0: PM: pci_pm_suspend(): nv_pmops_suspend [nvidia]
> returns -5"

The mailing list is not meant for reporting bugs. Please report this on
Launchpad. On the machine running the affected kernel, run:
$ ubuntu-bug linux

Thanks
...Juerg

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