Problem is probably due to insufficient implementation into the linux kernel. The dmesg log shows:

[   44.854875] bbswitch: loading out-of-tree module taints kernel.
[   44.854921] bbswitch: module verification failed: signature and/or required key missing - tainting kernel
[   44.856620] bbswitch: version 0.8
[   44.856804] bbswitch: Found integrated VGA device 0000:00:02.0: \_SB_.PCI0.GFX0
[   44.856811] bbswitch: Found discrete VGA device 0000:01:00.0: \_SB_.PCI0.PEG0.PEGP
[   44.856819] ACPI Warning: \_SB.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20180810/nsarguments-66)
[   44.856878] bbswitch: detected an Optimus _DSM function
[   44.856892] pci 0000:01:00.0: enabling device (0006 -> 0007)
[   44.856957] bbswitch: Succesfully loaded. Discrete card 0000:01:00.0 is on
[   44.858132] bbswitch: disabling discrete graphics
[   44.867701] version 39.2
[   44.869851] ipmi device interface
[   44.982711] nvidia: module license 'NVIDIA' taints kernel.
[   44.982712] Disabling lock debugging due to kernel taint
[   44.995623] nvidia-nvlink: Nvlink Core is being initialized, major device number 239
[   45.047689] NVRM: This is a 64-bit BAR mapped above 4GB by the system
               NVRM: BIOS or the Linux kernel, but the PCI bridge
               NVRM: immediately upstream of this GPU does not define
               NVRM: a matching prefetchable memory window.
[   45.047691] NVRM: This may be due to a known Linux kernel bug.  Please
               NVRM: see the README section on 64-bit BARs for additional
               NVRM: information.
[   45.047697] nvidia: probe of 0000:01:00.0 failed with error -1
[   45.047717] NVRM: The NVIDIA probe routine failed for 1 device(s).
[   45.047717] NVRM: None of the NVIDIA graphics adapters were initialized!
[   45.076626] nvidia-nvlink: Unregistered the Nvlink Core, major device number 23

But I don't know what to do next here.

Here is what NVIDA says about the error:

64-Bit BARs (Base Address Registers)

Starting with native PCI Express GPUs, NVIDIA's GPUs will advertise a 64-bit BAR capability (a Base Address Register stores the location of a PCI I/O region, such as registers or a frame buffer). This means that the GPU's PCI I/O regions (registers and frame buffer) can be placed above the 32-bit address space (the first 4 gigabytes of memory).

The decision of where the BAR is placed is made by the system BIOS at boot time. If the BIOS supports 64-bit BARs, then the NVIDIA PCI I/O regions may be placed above the 32-bit address space. If the BIOS does not support this feature, then our PCI I/O regions will be placed within the 32-bit address space as they have always been.

Unfortunately, some Linux kernels (such as 2.6.11.x) do not understand or support 64-bit BARs. If the BIOS does place any NVIDIA PCI I/O regions above the 32-bit address space, such kernels will reject the BAR and the NVIDIA driver will not work.

The only known workaround is to upgrade to a newer kernel.

 

what kernel version works with the DELL Precision 5530? - Ubuntu is currently at 5.0, I think.

forget the above message, it is not the actual error

The error is at primus/bumblebee which can not activate the card:

▶ primusrun glxgears                                             
/usr/bin/primusrun: line 41: warning: command substitution: ignored null byte in input
primus: fatal: Bumblebee daemon reported: error: Could not enable discrete graphics card
▶ sudo dmesg |tail -2
[ 1033.751425] bbswitch: enabling discrete graphics
[ 1033.751453] pci 0000:01:00.0: Refused to change power state, currently in D3

Could someone from DELL please look at the acpi dump that I posted on the nvidia form:

https://devtalk.nvidia.com/default/topic/1047727/linux/problem-with-quadro-p1000/post/5343119/#5343119

bbswitch is not running. switching to pure nvidia graphics would drain the battery a lot faster (and the battery is not very good anyway.)

It could be due to the following warning:

[ 33.401073] ACPI Warning: \_SB.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20180810/nsarguments-66)