Re: Connecting multiple TB3 eGPUs via USB4 hub?'

[Mika Westerberg <mika.westerberg@linux.intel.com>]

Hi,

On Mon, Jun 08, 2026 at 10:26:40AM -0500, Bjorn Helgaas wrote:
> [+cc linux-usb (Thunderbolt maintainers), Ilpo, Lukas]
> 
> On Sun, May 24, 2026 at 04:56:56PM +0200, Dag B wrote:
> > I am attempting to connect two TB3 enclosures to the same USB4 port via a
> > USB4 hub.
> > 
> > I cannot figure out of this is in violation of the TB3, TB4 or USB4 spec.
> 
> I'm not aware of a spec issue here.

It should be fine but typically PCIe resources for one tunneled PCIe root
port may not be enough for multiple GPUs. Therefore I suggest to connect
them directly to the host USB4 ports without a hub.

Second thing is that you have bunch of PCIe related command line parameters
that may affect. I suggest removing all of them, and retry. There is hardly
any reason to add these - the kernel should be able to handle this by
default.

Then provide full dmesg along with output of 'sudo lspci -vv' so we can
look a the resource allocation.

> Below it looks like you hot-added the hub.  Does it make any
> difference if everything is connected before boot?
> 
> Please don't filter the dmesg logs you collect.  We can do that if
> needed.
> 
> > .... or, in case it is not:
> > 
> > Can this work with current USB4/Thunderbolt drivers in Linux? (I am not
> > worried about bandwidth limitations.)
> > 
> > 
> > This appears to be too niche to find answers anywhere else. I would be very
> > grateful for any clarifying answer here, really.
> > 
> > 
> > Hardware
> > 
> > - Framework 13 mb with 12th gen Alder Lake (Intel Corporation Alder Lake-P
> > Thunderbolt 4 NHI)  (4 USB4 ports)
> > 
> > - Sonnettech Echo 5 hub (Intel Corporation Thunderbolt 4 Bridge [Goshen
> > Ridge 2020] )
> > 
> > - Razer Core X (Intel Corporation JHL6340 Thunderbolt 3 Bridge (C step)
> > [Alpine Ridge 2C 2016])
> > 
> > - GPUs are Nvidia RTX 3090. They expose two PCIe devices, the GPU and an
> > audio device.
> > 
> > 
> > Using kernel 7.0.10 with gentoo patches.
> > 
> > 
> > Been playing *a lot* with various permutations of pci-related kernel
> > options. Current options:
> > 
> > pci=realloc=on,hpmmiosize=256M,hpiosize=2M,hpmemsize=1G,hpbussize=0x33,pcie_scan_all,big_root_window
> > 
> > 
> > pcie_port_pm=off
> > 
> > pcie_aspm.policy=performance
> > 
> > thunderbolt.clx=0
> > 
> > 
> > 
> > Booting with 2 eGPUS directly connected to separate USB4 ports.  (pcie
> > messages only):
> > 
> > [    0.000000] Command line: root=/dev/nvme0n1p2 pci=realloc=on,hpmmiosize=256M,hpiosize=2M,hpmemsize=1G,hpbussize=0x33,pcie_scan_all,big_root_window
> > pcie_port_pm=off pcie_aspm.policy=performance thunderbolt.clx=0
> > [    0.082296] Kernel command line: pci=realloc=on,hpmmiosize=256M,hpiosize=2M,hpmemsize=1G,hpbussize=0x33,pcie_scan_all,big_root_window
> > \
> > [    0.082297] Kernel command line: pcie_port_pm=off
> > pcie_aspm.policy=performance \
> > [    0.864174] pcieport 0000:00:06.0: PME: Signaling with IRQ 122
> > [    0.864343] pcieport 0000:00:07.0: PME: Signaling with IRQ 123
> > [    0.864358] pcieport 0000:00:07.0: pciehp: Slot #3 AttnBtn- PwrCtrl- MRL-
> > AttnInd- PwrInd- HotPlug+ Surprise+ Interlock- NoCompl+ IbPresDis- LLActRep+
> > [    0.864661] pcieport 0000:00:07.1: PME: Signaling with IRQ 124
> > [    0.864677] pcieport 0000:00:07.1: pciehp: Slot #4 AttnBtn- PwrCtrl- MRL-
> > AttnInd- PwrInd- HotPlug+ Surprise+ Interlock- NoCompl+ IbPresDis- LLActRep+
> > [    0.864900] pcieport 0000:00:07.2: PME: Signaling with IRQ 125
> > [    0.864914] pcieport 0000:00:07.2: pciehp: Slot #5 AttnBtn- PwrCtrl- MRL-
> > AttnInd- PwrInd- HotPlug+ Surprise+ Interlock- NoCompl+ IbPresDis- LLActRep+
> > [    0.865139] pcieport 0000:00:07.3: PME: Signaling with IRQ 126
> > [    0.865153] pcieport 0000:00:07.3: pciehp: Slot #6 AttnBtn- PwrCtrl- MRL-
> > AttnInd- PwrInd- HotPlug+ Surprise+ Interlock- NoCompl+ IbPresDis- LLActRep+
> > [    0.865376] pcieport 0000:00:1d.0: PME: Signaling with IRQ 127
> > [    5.127515] pcieport 0000:00:07.3: pciehp: Slot(6): Card present
> > [    5.134225] pcieport 0000:00:07.0: pciehp: Slot(3): Card present
> > [    5.263158] pcieport 0000:00:07.3: bridge window [io  size 0x200000]:
> > can't assign; no space
> > [    5.263178] pcieport 0000:00:07.3: bridge window [io  size 0x200000]:
> > failed to assign
> > [    5.263197] pcieport 0000:00:07.3: bridge window [io  size 0x200000]:
> > can't assign; no space
> > [    5.263215] pcieport 0000:00:07.3: bridge window [io  size 0x200000]:
> > failed to assign
> > [    5.270527] pcieport 0000:00:07.3: PCI bridge to [bus 7d-a5]
> > [    5.270529] pcieport 0000:00:07.3:   bridge window [mem
> > 0x52000000-0x5e1fffff]
> > [    5.270531] pcieport 0000:00:07.3:   bridge window [mem
> > 0x6060000000-0x607bffffff 64bit pref]
> > [    5.270537] pcieport 0000:00:07.3: bridge window [io  size 0x200000]:
> > can't assign; no space
> > [    5.270537] pcieport 0000:00:07.3: bridge window [io  size 0x200000]:
> > failed to assign
> > [    5.270538] pcieport 0000:00:07.3: bridge window [io  size 0x200000]:
> > can't assign; no space
> > [    5.270539] pcieport 0000:00:07.3: bridge window [io  size 0x200000]:
> > failed to assign
> > [    5.270577] pcieport 0000:00:07.3: PCI bridge to [bus 7d-a5]
> > [    5.270579] pcieport 0000:00:07.3:   bridge window [mem
> > 0x52000000-0x5e1fffff]
> > [    5.270581] pcieport 0000:00:07.3:   bridge window [mem
> > 0x6060000000-0x607bffffff 64bit pref]
> > [    5.270703] pcieport 0000:7d:00.0: enabling device (0000 -> 0002)
> > [    5.287127] pcieport 0000:7e:01.0: enabling device (0000 -> 0002)
> > [    5.325065] pcieport 0000:00:07.0: bridge window [io  size 0x200000]:
> > can't assign; no space
> > [    5.325560] pcieport 0000:00:07.0: bridge window [io  size 0x200000]:
> > failed to assign
> > [    5.326061] pcieport 0000:00:07.0: bridge window [io  size 0x200000]:
> > can't assign; no space
> > [    5.326560] pcieport 0000:00:07.0: bridge window [io  size 0x200000]:
> > failed to assign
> > [    5.340678] pcieport 0000:00:07.0: PCI bridge to [bus 02-2a]
> > [    5.340680] pcieport 0000:00:07.0:   bridge window [mem
> > 0x7c000000-0x881fffff]
> > [    5.340682] pcieport 0000:00:07.0:   bridge window [mem
> > 0x6000000000-0x601bffffff 64bit pref]
> > [    5.340688] pcieport 0000:00:07.0: bridge window [io  size 0x200000]:
> > can't assign; no space
> > [    5.340689] pcieport 0000:00:07.0: bridge window [io  size 0x200000]:
> > failed to assign
> > [    5.340690] pcieport 0000:00:07.0: bridge window [io  size 0x200000]:
> > can't assign; no space
> > [    5.340690] pcieport 0000:00:07.0: bridge window [io  size 0x200000]:
> > failed to assign
> > [    5.340741] pcieport 0000:00:07.0: PCI bridge to [bus 02-2a]
> > [    5.340744] pcieport 0000:00:07.0:   bridge window [mem
> > 0x7c000000-0x881fffff]
> > [    5.340745] pcieport 0000:00:07.0:   bridge window [mem
> > 0x6000000000-0x601bffffff 64bit pref]
> > [    5.340866] pcieport 0000:02:00.0: enabling device (0000 -> 0002)
> > [    5.355410] pcieport 0000:03:01.0: enabling device (0000 -> 0002)
> > 
> > 
> > Then, connecting the hub with two additional eGPUs to a third USB4 port (all
> > messages):
> > 
> > [  596.449718] thunderbolt 0-3: new device found, vendor=0x8 device=0x5f
> > [  596.449771] thunderbolt 0-3: Sonnet Technologies, Inc. Echo 5 Thunderbolt
> > 4 Hub
> > [  596.710380] thunderbolt 0-0:3.1: new retimer found, vendor=0x8087
> > device=0x15ee
> > [  596.962295] usb 3-3: new high-speed USB device number 4 using xhci_hcd
> > [  597.156102] usb 3-3: New USB device found, idVendor=1d5c, idProduct=5801,
> > bcdDevice= 1.01
> > [  597.156118] usb 3-3: New USB device strings: Mfr=1, Product=2,
> > SerialNumber=0
> > [  597.156130] usb 3-3: Product: USB2.0 Hub
> > [  597.156138] usb 3-3: Manufacturer: Fresco Logic, Inc.
> > [  597.157120] hub 3-3:1.0: USB hub found
> > [  597.157152] hub 3-3:1.0: 6 ports detected
> > [  597.458933] usb 2-2: new SuperSpeed Plus Gen 2x1 USB device number 4
> > using xhci_hcd
> > [  597.472670] usb 2-2: New USB device found, idVendor=8087, idProduct=0b40,
> > bcdDevice=12.34
> > [  597.472687] usb 2-2: New USB device strings: Mfr=1, Product=2,
> > SerialNumber=0
> > [  597.472700] usb 2-2: Product: USB3.0 Hub
> > [  597.472711] usb 2-2: Manufacturer: Intel Corporation.
> > [  597.473459] hub 2-2:1.0: USB hub found
> > [  597.473587] hub 2-2:1.0: 4 ports detected
> > [  597.559335] thunderbolt 0-303: new device found, vendor=0x127 device=0x1
> > [  597.559350] thunderbolt 0-303: Razer Core X
> > [  597.702310] usb 3-3.5: new full-speed USB device number 5 using xhci_hcd
> > [  597.801389] usb 3-3.5: New USB device found, idVendor=2a8c,
> > idProduct=205f, bcdDevice=17.46
> > [  597.801406] usb 3-3.5: New USB device strings: Mfr=1, Product=2,
> > SerialNumber=3
> > [  597.801418] usb 3-3.5: Product: Echo 5 Thunderbolt 4 Hub
> > [  597.801428] usb 3-3.5: Manufacturer: Sonnet Technologies,Inc.
> > [  597.801438] usb 3-3.5: SerialNumber: 11AD1D0A510D2E0D381E0B00
> > [  597.885632] usb 3-3.6: new high-speed USB device number 6 using xhci_hcd
> > [  597.983768] usb 3-3.6: New USB device found, idVendor=1d5c,
> > idProduct=5530, bcdDevice= 1.01
> > [  597.983785] usb 3-3.6: New USB device strings: Mfr=1, Product=2,
> > SerialNumber=0
> > [  597.983798] usb 3-3.6: Product: Frescologic VENDOR HID
> > [  597.983807] usb 3-3.6: Manufacturer: Frescologic
> > [  597.985769] hid-generic 0003:1D5C:5530.0002: hidraw1: USB HID v1.01
> > Device [Frescologic Frescologic VENDOR HID] on usb-0000:00:14.0-3.6/input0
> > [  598.294042] thunderbolt 0-503: new device found, vendor=0x127 device=0x1
> > [  598.294057] thunderbolt 0-503: Razer Core X
> > [  598.619985] pcieport 0000:00:07.1: pciehp: Slot(4): Card present
> > [  598.619999] pcieport 0000:00:07.1: pciehp: Slot(4): Link Up
> > [  598.745860] pci 0000:2b:00.0: [8086:0b26] type 01 class 0x060400 PCIe
> > Switch Upstream Port
> > [  598.745987] pci 0000:2b:00.0: PCI bridge to [bus 00]
> > [  598.746028] pci 0000:2b:00.0:   bridge window [io 0x0000-0x0fff]
> > [  598.746061] pci 0000:2b:00.0:   bridge window [mem 0x00000000-0x000fffff]
> > [  598.746113] pci 0000:2b:00.0:   bridge window [mem 0x00000000-0x000fffff
> > 64bit pref]
> > [  598.746173] pci 0000:2b:00.0: enabling Extended Tags
> > [  598.746450] pci 0000:2b:00.0: supports D1 D2
> > [  598.746471] pci 0000:2b:00.0: PME# supported from D0 D1 D2 D3hot D3cold
> > [  598.747002] pci 0000:2b:00.0: Adding to iommu group 22
> > [  598.755705] pci 0000:2b:00.0: bridge configuration invalid ([bus 00-00]),
> > reconfiguring
> > [  598.755945] pci 0000:2c:00.0: [8086:0b26] type 01 class 0x060400 PCIe
> > Switch Downstream Port
> > [  598.756014] pci 0000:2c:00.0: PCI bridge to [bus 00]
> > [  598.756039] pci 0000:2c:00.0:   bridge window [io 0x0000-0x0fff]
> > [  598.756059] pci 0000:2c:00.0:   bridge window [mem 0x00000000-0x000fffff]
> > [  598.756094] pci 0000:2c:00.0:   bridge window [mem 0x00000000-0x000fffff
> > 64bit pref]
> > [  598.756136] pci 0000:2c:00.0: enabling Extended Tags
> > [  598.756346] pci 0000:2c:00.0: supports D1 D2
> > [  598.756359] pci 0000:2c:00.0: PME# supported from D0 D1 D2 D3hot D3cold
> > [  598.756675] pci 0000:2c:00.0: Adding to iommu group 23
> > [  598.756854] pci 0000:2c:01.0: [8086:0b26] type 01 class 0x060400 PCIe
> > Switch Downstream Port
> > [  598.756925] pci 0000:2c:01.0: PCI bridge to [bus 00]
> > [  598.756950] pci 0000:2c:01.0:   bridge window [io 0x0000-0x0fff]
> > [  598.756970] pci 0000:2c:01.0:   bridge window [mem 0x00000000-0x000fffff]
> > [  598.757863] pci 0000:2c:01.0:   bridge window [mem 0x00000000-0x000fffff
> > 64bit pref]
> > [  598.758743] pci 0000:2c:01.0: enabling Extended Tags
> > [  598.759822] pci 0000:2c:01.0: supports D1 D2
> > [  598.760599] pci 0000:2c:01.0: PME# supported from D0 D1 D2 D3hot D3cold
> > [  598.761582] pci 0000:2c:01.0: Adding to iommu group 24
> > [  598.762477] pci 0000:2c:02.0: [8086:0b26] type 01 class 0x060400 PCIe
> > Switch Downstream Port
> > [  598.763270] pci 0000:2c:02.0: PCI bridge to [bus 00]
> > [  598.764010] pci 0000:2c:02.0:   bridge window [io 0x0000-0x0fff]
> > [  598.764697] pci 0000:2c:02.0:   bridge window [mem 0x00000000-0x000fffff]
> > [  598.765266] pci 0000:2c:02.0:   bridge window [mem 0x00000000-0x000fffff
> > 64bit pref]
> > [  598.765832] pci 0000:2c:02.0: enabling Extended Tags
> > [  598.766513] pci 0000:2c:02.0: supports D1 D2
> > [  598.767016] pci 0000:2c:02.0: PME# supported from D0 D1 D2 D3hot D3cold
> > [  598.767686] pci 0000:2c:02.0: Adding to iommu group 25
> > [  598.768272] pci 0000:2c:03.0: [8086:0b26] type 01 class 0x060400 PCIe
> > Switch Downstream Port
> > [  598.768804] pci 0000:2c:03.0: PCI bridge to [bus 00]
> > [  598.769323] pci 0000:2c:03.0:   bridge window [io 0x0000-0x0fff]
> > [  598.769815] pci 0000:2c:03.0:   bridge window [mem 0x00000000-0x000fffff]
> > [  598.770317] pci 0000:2c:03.0:   bridge window [mem 0x00000000-0x000fffff
> > 64bit pref]
> > [  598.770816] pci 0000:2c:03.0: enabling Extended Tags
> > [  598.771451] pci 0000:2c:03.0: supports D1 D2
> > [  598.771929] pci 0000:2c:03.0: PME# supported from D0 D1 D2 D3hot D3cold
> > [  598.772596] pci 0000:2c:03.0: Adding to iommu group 26
> > [  598.773173] pci 0000:2c:04.0: [8086:0b26] type 01 class 0x060400 PCIe
> > Switch Downstream Port
> > [  598.773694] pci 0000:2c:04.0: PCI bridge to [bus 00]
> > [  598.774196] pci 0000:2c:04.0:   bridge window [io 0x0000-0x0fff]
> > [  598.774683] pci 0000:2c:04.0:   bridge window [mem 0x00000000-0x000fffff]
> > [  598.775179] pci 0000:2c:04.0:   bridge window [mem 0x00000000-0x000fffff
> > 64bit pref]
> > [  598.775687] pci 0000:2c:04.0: enabling Extended Tags
> > [  598.776319] pci 0000:2c:04.0: supports D1 D2
> > [  598.776794] pci 0000:2c:04.0: PME# supported from D0 D1 D2 D3hot D3cold
> > [  598.777437] pci 0000:2c:04.0: Adding to iommu group 27
> > [  598.777985] pci 0000:2b:00.0: PCI bridge to [bus 2c-53]
> > [  598.778481] pci 0000:2c:00.0: bridge configuration invalid ([bus 00-00]),
> > reconfiguring
> > [  598.778983] pci 0000:2c:01.0: bridge configuration invalid ([bus 00-00]),
> > reconfiguring
> > [  598.779463] pci 0000:2c:02.0: bridge configuration invalid ([bus 00-00]),
> > reconfiguring
> > [  598.779939] pci 0000:2c:03.0: bridge configuration invalid ([bus 00-00]),
> > reconfiguring
> > [  598.780408] pci 0000:2c:04.0: bridge configuration invalid ([bus 00-00]),
> > reconfiguring
> > [  598.780987] pci 0000:2c:00.0: PCI bridge to [bus 2d-53]
> > [  598.781458] pci_bus 0000:2d: busn_res: [bus 2d-53] end is updated to 2d
> > [  598.782096] pci 0000:2e:00.0: [8086:15da] type 01 class 0x060400 PCIe
> > Switch Upstream Port
> > [  598.782628] pci 0000:2e:00.0: PCI bridge to [bus 00]
> > [  598.783089] pci 0000:2e:00.0:   bridge window [io 0x0000-0x0fff]
> > [  598.783548] pci 0000:2e:00.0:   bridge window [mem 0x00000000-0x000fffff]
> > [  598.784020] pci 0000:2e:00.0:   bridge window [mem 0x00000000-0x000fffff
> > 64bit pref]
> > [  598.784493] pci 0000:2e:00.0: enabling Extended Tags
> > [  598.785172] pci 0000:2e:00.0: supports D1 D2
> > [  598.785624] pci 0000:2e:00.0: PME# supported from D0 D1 D2 D3hot D3cold
> > [  598.786319] pci 0000:2e:00.0: Adding to iommu group 28
> > [  598.792407] pci 0000:2c:01.0: PCI bridge to [bus 2e-53]
> > [  598.792880] pci 0000:2e:00.0: bridge configuration invalid ([bus 00-00]),
> > reconfiguring
> > [  598.793579] pci 0000:2f:01.0: [8086:15da] type 01 class 0x060400 PCIe
> > Switch Downstream Port
> > [  598.794094] pci 0000:2f:01.0: PCI bridge to [bus 00]
> > [  598.794559] pci 0000:2f:01.0:   bridge window [io 0x0000-0x0fff]
> > [  598.795014] pci 0000:2f:01.0:   bridge window [mem 0x00000000-0x000fffff]
> > [  598.795485] pci 0000:2f:01.0:   bridge window [mem 0x00000000-0x000fffff
> > 64bit pref]
> > [  598.795981] pci 0000:2f:01.0: enabling Extended Tags
> > [  598.796665] pci 0000:2f:01.0: supports D1 D2
> > [  598.797111] pci 0000:2f:01.0: PME# supported from D0 D1 D2 D3hot D3cold
> > [  598.797785] pci 0000:2f:01.0: Adding to iommu group 29
> > [  598.798344] pci 0000:2e:00.0: PCI bridge to [bus 2f-53]
> > [  598.798826] pci 0000:2f:01.0: bridge configuration invalid ([bus 00-00]),
> > reconfiguring
> > [  598.799576] pci 0000:30:00.0: [10de:2204] type 00 class 0x030000 PCIe
> > Legacy Endpoint
> > [  598.800146] pci 0000:30:00.0: BAR 0 [mem 0x00000000-0x00ffffff]
> > [  598.800598] pci 0000:30:00.0: BAR 1 [mem 0x00000000-0x0fffffff 64bit
> > pref]
> > [  598.801062] pci 0000:30:00.0: BAR 3 [mem 0x00000000-0x01ffffff 64bit
> > pref]
> > [  598.801512] pci 0000:30:00.0: BAR 5 [io  0x0000-0x007f]
> > [  598.801961] pci 0000:30:00.0: ROM [mem 0x00000000-0x0007ffff pref]
> > [  598.802697] pci 0000:30:00.0: PME# supported from D0 D3hot
> > [  598.803421] pci 0000:30:00.0: 8.000 Gb/s available PCIe bandwidth,
> > limited by 2.5 GT/s PCIe x4 link at 0000:00:07.1 (capable of 252.048 Gb/s
> > with 16.0 GT/s PCIe x16 link)
> > [  598.804053] pci 0000:30:00.0: Adding to iommu group 29
> > [  598.804517] pci 0000:30:00.0: vgaarb: bridge control possible
> > [  598.804969] pci 0000:30:00.0: vgaarb: VGA device added:
> > decodes=io+mem,owns=none,locks=none
> > [  598.805427] i915 0000:00:02.0: vgaarb: VGA decodes changed:
> > olddecodes=none,decodes=none:owns=io+mem
> > [  598.806033] pci 0000:30:00.1: [10de:1aef] type 00 class 0x040300 PCIe
> > Endpoint
> > [  598.806622] pci 0000:30:00.1: BAR 0 [mem 0x00000000-0x00003fff]
> > [  598.807434] pci 0000:30:00.1: Adding to iommu group 29
> > [  598.808118] pci 0000:2f:01.0: PCI bridge to [bus 30-53]
> > [  598.808614] pci_bus 0000:30: busn_res: [bus 30-53] end is updated to 30
> > [  598.809107] pci_bus 0000:2f: busn_res: [bus 2f-53] end is updated to 30
> > [  598.809575] pci_bus 0000:2e: busn_res: [bus 2e-53] end is updated to 53
> > [  598.810077] pci_bus 0000:54: busn_res: [bus 54-7c] end is updated to 7c
> > [  598.810714] pci_bus 0000:7d: busn_res: [bus 7d-a5] end is updated to a5
> > [  598.811226] pci_bus 0000:a6: busn_res: [bus a6] end is updated to a6
> > [  598.811682] pci_bus 0000:2c: busn_res: [bus 2c-53] end can not be updated
> > to a6
> > [  598.812141] pci 0000:2c:00.0: disabling bridge window [mem
> > 0x00000000-0x000fffff 64bit pref] to [bus 2d] (unused)
> > [  598.812621] pci 0000:2c:00.0: disabling bridge window [mem
> > 0x00000000-0x000fffff] to [bus 2d] (unused)
> > [  598.813082] pci 0000:2c:01.0: bridge window [io  0x1000-0x1fff] to [bus
> > 2e-53] add_size 1ff000
> > [  598.813544] pci 0000:2c:01.0: bridge window [mem 0x10000000-0x21ffffff
> > 64bit pref] to [bus 2e-53] add_size 2e000000 add_align 10000000
> > [  598.814007] pci 0000:2c:01.0: bridge window [mem 0x01000000-0x020fffff]
> > to [bus 2e-53] add_size 3ef00000 add_align 1000000
> > [  598.814474] pci 0000:2b:00.0: bridge window [io  0x1000-0x2fff] to [bus
> > 2c-53] add_size 1ff000
> > [  598.814942] pci 0000:2b:00.0: bridge window [mem 0x10000000-0x21ffffff
> > 64bit pref] to [bus 2c-53] add_size 2e000000 add_align 10000000
> > [  598.815414] pci 0000:2b:00.0: bridge window [mem 0x01000000-0x020fffff]
> > to [bus 2c-53] add_size 3ef00000 add_align 1000000
> > [  598.815908] pcieport 0000:00:07.1: bridge window [io  size 0x200000] to
> > [bus 2b-53] add_size 1ff000
> > [  598.816393] pcieport 0000:00:07.1: bridge window [io  size 0x3ff000]:
> > can't assign; no space
> > [  598.816870] pcieport 0000:00:07.1: bridge window [io  size 0x3ff000]:
> > failed to assign
> > [  598.817346] pcieport 0000:00:07.1: bridge window [io  size 0x200000]:
> > can't assign; no space
> > [  598.817828] pcieport 0000:00:07.1: bridge window [io  size 0x200000]:
> > failed to assign
> > [  598.818304] pci 0000:2b:00.0: bridge window [mem size 0x40000000 64bit
> > pref]: can't assign; no space
> > [  598.818785] pci 0000:2b:00.0: bridge window [mem size 0x40000000 64bit
> > pref]: failed to assign
> > [  598.819281] pci 0000:2b:00.0: bridge window [mem 0x6e000000-0x7a0fffff]:
> > assigned
> > [  598.819765] pci 0000:2b:00.0: bridge window [io  size 0x200000]: can't
> > assign; no space
> > [  598.820250] pci 0000:2b:00.0: bridge window [io  size 0x200000]: failed
> > to assign
> > [  598.820740] pci 0000:2b:00.0: bridge window [mem 0x6e000000-0x7a0fffff]:
> > releasing
> > [  598.821235] pci 0000:2b:00.0: bridge window [mem
> > 0x6020000000-0x6031ffffff 64bit pref]: assigned
> > [  598.821727] pci 0000:2b:00.0: bridge window [mem 0x6e000000-0x7a0fffff]:
> > assigned
> > [  598.822227] pci 0000:2b:00.0: bridge window [io  size 0x200000]: can't
> > assign; no space
> > [  598.822722] pci 0000:2b:00.0: bridge window [io  size 0x200000]: failed
> > to assign
> > [  598.823206] pci 0000:2b:00.0: bridge window [mem
> > 0x6020000000-0x6031ffffff 64bit pref]: failed to expand by 0x2e000000
> > [  598.823697] pci 0000:2b:00.0: bridge window [mem
> > 0x6020000000-0x6031ffffff 64bit pref]: failed to add optional 2e000000
> > [  598.824186] pci 0000:2c:01.0: bridge window [mem size 0x40000000 64bit
> > pref]: can't assign; no space
> > [  598.824679] pci 0000:2c:01.0: bridge window [mem size 0x40000000 64bit
> > pref]: failed to assign
> > [  598.825173] pci 0000:2c:01.0: bridge window [mem 0x6e000000-0x720fffff]:
> > assigned
> > [  598.825677] pci 0000:2c:00.0: bridge window [io  size 0x1000]: can't
> > assign; no space
> > [  598.826173] pci 0000:2c:00.0: bridge window [io  size 0x1000]: failed to
> > assign
> > [  598.826666] pci 0000:2c:01.0: bridge window [io  size 0xab000]: can't
> > assign; no space
> > [  598.827161] pci 0000:2c:01.0: bridge window [io  size 0xab000]: failed to
> > assign
> > [  598.827652] pci 0000:2c:01.0: bridge window [mem 0x6e000000-0x720fffff]:
> > releasing
> > [  598.828140] pci 0000:2c:01.0: bridge window [mem
> > 0x6020000000-0x6031ffffff 64bit pref]: assigned
> > [  598.828630] pci 0000:2c:01.0: bridge window [mem 0x6e000000-0x720fffff]:
> > assigned
> > [  598.829132] pci 0000:2c:00.0: bridge window [io  size 0x1000]: can't
> > assign; no space
> > [  598.829623] pci 0000:2c:00.0: bridge window [io  size 0x1000]: failed to
> > assign
> > [  598.830116] pci 0000:2c:01.0: bridge window [io  size 0xab000]: can't
> > assign; no space
> > [  598.830606] pci 0000:2c:01.0: bridge window [io  size 0xab000]: failed to
> > assign
> > [  598.831099] pci 0000:2c:01.0: bridge window [mem
> > 0x6020000000-0x6031ffffff 64bit pref]: failed to expand by 0x2e000000
> > [  598.831588] pci 0000:2c:01.0: bridge window [mem
> > 0x6020000000-0x6031ffffff 64bit pref]: failed to add optional 2e000000
> > [  598.832080] pci 0000:2c:00.0: PCI bridge to [bus 2d]
> > [  598.832605] pci 0000:2e:00.0: bridge window [mem
> > 0x6020000000-0x6031ffffff 64bit pref]: assigned
> > [  598.833106] pci 0000:2e:00.0: bridge window [mem 0x6e000000-0x720fffff]:
> > assigned
> > [  598.833599] pci 0000:2e:00.0: bridge window [io  size 0xab000]: can't
> > assign; no space
> > [  598.834091] pci 0000:2e:00.0: bridge window [io  size 0xab000]: failed to
> > assign
> > [  598.834590] pci 0000:2e:00.0: bridge window [io  size 0xab000]: can't
> > assign; no space
> > [  598.835088] pci 0000:2e:00.0: bridge window [io  size 0xab000]: failed to
> > assign
> > [  598.835592] pci 0000:2f:01.0: bridge window [mem
> > 0x6020000000-0x6031ffffff 64bit pref]: assigned
> > [  598.836098] pci 0000:2f:01.0: bridge window [mem 0x6e000000-0x720fffff]:
> > assigned
> > [  598.836600] pci 0000:2f:01.0: bridge window [io  size 0xab000]: can't
> > assign; no space
> > [  598.837097] pci 0000:2f:01.0: bridge window [io  size 0xab000]: failed to
> > assign
> > [  598.837585] pci 0000:2f:01.0: bridge window [io  size 0xab000]: can't
> > assign; no space
> > [  598.838073] pci 0000:2f:01.0: bridge window [io  size 0xab000]: failed to
> > assign
> > [  598.838559] pci 0000:30:00.0: BAR 1 [mem 0x6020000000-0x602fffffff 64bit
> > pref]: assigned
> > [  598.839079] pci 0000:30:00.0: BAR 3 [mem 0x6030000000-0x6031ffffff 64bit
> > pref]: assigned
> > [  598.839581] pci 0000:30:00.0: BAR 0 [mem 0x6e000000-0x6effffff]: assigned
> > [  598.840063] pci 0000:30:00.0: ROM [mem 0x6f000000-0x6f07ffff pref]:
> > assigned
> > [  598.840538] pci 0000:30:00.1: BAR 0 [mem 0x6f080000-0x6f083fff]: assigned
> > [  598.841020] pci 0000:30:00.0: BAR 5 [io  size 0x0080]: can't assign; no
> > space
> > [  598.841496] pci 0000:30:00.0: BAR 5 [io  size 0x0080]: failed to assign
> > [  598.841974] pci 0000:30:00.0: BAR 5 [io  size 0x0080]: can't assign; no
> > space
> > [  598.842463] pci 0000:30:00.0: BAR 5 [io  size 0x0080]: failed to assign
> > [  598.842941] pci 0000:2f:01.0: PCI bridge to [bus 30]
> > [  598.843429] pci 0000:2f:01.0:   bridge window [mem 0x6e000000-0x720fffff]
> > [  598.843918] pci 0000:2f:01.0:   bridge window [mem
> > 0x6020000000-0x6031ffffff 64bit pref]
> > [  598.844415] pci 0000:2e:00.0: PCI bridge to [bus 2f-30]
> > [  598.844901] pci 0000:2e:00.0:   bridge window [mem 0x6e000000-0x720fffff]
> > [  598.845388] pci 0000:2e:00.0:   bridge window [mem
> > 0x6020000000-0x6031ffffff 64bit pref]
> > [  598.845890] pci 0000:2c:01.0: PCI bridge to [bus 2e-53]
> > [  598.846369] pci 0000:2c:01.0:   bridge window [mem 0x6e000000-0x720fffff]
> > [  598.846845] pci 0000:2c:01.0:   bridge window [mem
> > 0x6020000000-0x6031ffffff 64bit pref]
> > [  598.847319] pci 0000:2b:00.0: PCI bridge to [bus 2c-53]
> > [  598.847789] pci 0000:2b:00.0:   bridge window [mem 0x6e000000-0x7a0fffff]
> > [  598.848255] pci 0000:2b:00.0:   bridge window [mem
> > 0x6020000000-0x6031ffffff 64bit pref]
> > [  598.848720] pcieport 0000:00:07.1: PCI bridge to [bus 2b-53]
> > [  598.849198] pcieport 0000:00:07.1:   bridge window [mem
> > 0x6e000000-0x7a1fffff]
> > [  598.849667] pcieport 0000:00:07.1:   bridge window [mem
> > 0x6020000000-0x603bffffff 64bit pref]
> > [  598.850136] PCI: No. 2 try to assign unassigned res
> > [  598.850602] pci 0000:2c:00.0: disabling bridge window [mem
> > 0x00000000-0x000fffff 64bit pref disabled] to [bus 2d] (unused)
> > [  598.851083] pci 0000:2c:00.0: disabling bridge window [mem
> > 0x00000000-0x000fffff disabled] to [bus 2d] (unused)
> > [  598.851556] pci 0000:2c:01.0: bridge window [io  size 0xab000] to [bus
> > 2e-53] add_size 155000
> > [  598.852035] pci 0000:2b:00.0: bridge window [io  size 0x200000] to [bus
> > 2c-53] add_size 155000
> > [  598.852530] pcieport 0000:00:07.1: bridge window [io  size 0x200000] to
> > [bus 2b-53] add_size 155000
> > [  598.853014] pcieport 0000:00:07.1: bridge window [io  size 0x355000]:
> > can't assign; no space
> > [  598.853493] pcieport 0000:00:07.1: bridge window [io  size 0x355000]:
> > failed to assign
> > [  598.853971] pcieport 0000:00:07.1: bridge window [io  size 0x200000]:
> > can't assign; no space
> > [  598.854448] pcieport 0000:00:07.1: bridge window [io  size 0x200000]:
> > failed to assign
> > [  598.854921] pci 0000:2b:00.0: bridge window [io  size 0x355000]: can't
> > assign; no space
> > [  598.855401] pci 0000:2b:00.0: bridge window [io  size 0x355000]: failed
> > to assign
> > [  598.855896] pci 0000:2b:00.0: bridge window [io  size 0x200000]: can't
> > assign; no space
> > [  598.856376] pci 0000:2b:00.0: bridge window [io  size 0x200000]: failed
> > to assign
> > [  598.856847] pci 0000:2c:00.0: bridge window [io  size 0x1000]: can't
> > assign; no space
> > [  598.857319] pci 0000:2c:00.0: bridge window [io  size 0x1000]: failed to
> > assign
> > [  598.857788] pci 0000:2c:01.0: bridge window [io  size 0x11c000]: can't
> > assign; no space
> > [  598.858255] pci 0000:2c:01.0: bridge window [io  size 0x11c000]: failed
> > to assign
> > [  598.858722] pci 0000:2c:00.0: bridge window [io  size 0x1000]: can't
> > assign; no space
> > [  598.859209] pci 0000:2c:00.0: bridge window [io  size 0x1000]: failed to
> > assign
> > [  598.859677] pci 0000:2c:01.0: bridge window [io  size 0x11c000]: can't
> > assign; no space
> > [  598.860143] pci 0000:2c:01.0: bridge window [io  size 0x11c000]: failed
> > to assign
> > [  598.860609] pci 0000:2c:00.0: PCI bridge to [bus 2d]
> > [  598.861088] pci 0000:2e:00.0: bridge window [io  size 0x11c000]: can't
> > assign; no space
> > [  598.861556] pci 0000:2e:00.0: bridge window [io  size 0x11c000]: failed
> > to assign
> > [  598.862018] pci 0000:2e:00.0: bridge window [io  size 0x11c000]: can't
> > assign; no space
> > [  598.862501] pci 0000:2e:00.0: bridge window [io  size 0x11c000]: failed
> > to assign
> > [  598.862970] pci 0000:2f:01.0: bridge window [io  size 0x11c000]: can't
> > assign; no space
> > [  598.863429] pci 0000:2f:01.0: bridge window [io  size 0x11c000]: failed
> > to assign
> > [  598.863891] pci 0000:2f:01.0: bridge window [io  size 0x11c000]: can't
> > assign; no space
> > [  598.864349] pci 0000:2f:01.0: bridge window [io  size 0x11c000]: failed
> > to assign
> > [  598.864802] pci 0000:30:00.0: BAR 5 [io  size 0x0080]: can't assign; no
> > space
> > [  598.865254] pci 0000:30:00.0: BAR 5 [io  size 0x0080]: failed to assign
> > [  598.865715] pci 0000:30:00.0: BAR 5 [io  size 0x0080]: can't assign; no
> > space
> > [  598.866163] pci 0000:30:00.0: BAR 5 [io  size 0x0080]: failed to assign
> > [  598.866615] pci 0000:2f:01.0: PCI bridge to [bus 30]
> > [  598.867073] pci 0000:2f:01.0:   bridge window [mem 0x6e000000-0x720fffff]
> > [  598.867528] pci 0000:2f:01.0:   bridge window [mem
> > 0x6020000000-0x6031ffffff 64bit pref]
> > [  598.867992] pci 0000:2e:00.0: PCI bridge to [bus 2f-30]
> > [  598.868448] pci 0000:2e:00.0:   bridge window [mem 0x6e000000-0x720fffff]
> > [  598.868907] pci 0000:2e:00.0:   bridge window [mem
> > 0x6020000000-0x6031ffffff 64bit pref]
> > [  598.869374] pci 0000:2c:01.0: PCI bridge to [bus 2e-53]
> > [  598.869833] pci 0000:2c:01.0:   bridge window [mem 0x6e000000-0x720fffff]
> > [  598.870286] pci 0000:2c:01.0:   bridge window [mem
> > 0x6020000000-0x6031ffffff 64bit pref]
> > [  598.870749] pci 0000:2b:00.0: PCI bridge to [bus 2c-53]
> > [  598.871209] pci 0000:2b:00.0:   bridge window [mem 0x6e000000-0x7a0fffff]
> > [  598.871670] pci 0000:2b:00.0:   bridge window [mem
> > 0x6020000000-0x6031ffffff 64bit pref]
> > [  598.872132] pcieport 0000:00:07.1: PCI bridge to [bus 2b-53]
> > [  598.872613] pcieport 0000:00:07.1:   bridge window [mem
> > 0x6e000000-0x7a1fffff]
> > [  598.873080] pcieport 0000:00:07.1:   bridge window [mem
> > 0x6020000000-0x603bffffff 64bit pref]
> > [  598.873649] pcieport 0000:2b:00.0: enabling device (0000 -> 0002)
> > [  598.874666] pcieport 0000:2c:01.0: enabling device (0000 -> 0002)
> > [  598.875244] pcieport 0000:2c:01.0: pciehp: Slot #1 AttnBtn- PwrCtrl- MRL-
> > AttnInd- PwrInd- HotPlug+ Surprise+ Interlock- NoCompl+ IbPresDis- LLActRep+
> > [  598.876454] pcieport 0000:2c:02.0: pciehp: Hotplug bridge without
> > secondary bus, ignoring
> > [  598.877284] pcieport 0000:2c:03.0: pciehp: Hotplug bridge without
> > secondary bus, ignoring
> > [  598.878335] pcieport 0000:2e:00.0: enabling device (0000 -> 0002)
> > [  598.879210] pcieport 0000:2f:01.0: enabling device (0000 -> 0002)
> > [  598.880224] nvidia 0000:30:00.0: enabling device (0000 -> 0002)
> > [  598.880833] nvidia 0000:30:00.0: vgaarb: VGA decodes changed:
> > olddecodes=io+mem,decodes=none:owns=none
> > [  599.171370] [drm] [nvidia-drm] [GPU ID 0x00003000] Loading driver
> > [  599.172273] [drm] Initialized nvidia-drm 0.0.0 for 0000:30:00.0 on minor
> > 3
> > [  599.172936] pci 0000:30:00.1: extending delay after power-on from D3hot
> > to 20 msec
> > [  599.173650] pci 0000:30:00.1: D0 power state depends on 0000:30:00.0
> > [  683.104898] Loading firmware: nvidia/595.71.05/gsp_ga10x.bin
> > [  683.634039] Loading firmware: nvidia/595.71.05/gsp_ga10x.bin
> > [  684.043158] Loading firmware: nvidia/595.71.05/gsp_ga10x.bin
> > 
> > So, only one of the two hub-connected eGPUs are recognized.
> > 
> > 
> > pciehp: Hotplug bridge without secondary bus, ignoring <-  This sounds less
> > promising.
> > 
> > 
> > lspci (after connecting hub):
> > 
> > 00:00.0 Host bridge: Intel Corporation 12th Gen Core Processor Host
> > Bridge/DRAM Registers (rev 02)
> > 00:02.0 VGA compatible controller: Intel Corporation Alder Lake-P GT2 [Iris
> > Xe Graphics] (rev 0c)
> > 00:04.0 Signal processing controller: Intel Corporation Alder Lake
> > Innovation Platform Framework Processor Participant (rev 02)
> > 00:06.0 PCI bridge: Intel Corporation 12th Gen Core Processor PCI Express x4
> > Controller #0 (rev 02)
> > 00:07.0 PCI bridge: Intel Corporation Alder Lake-P Thunderbolt 4 PCI Express
> > Root Port #0 (rev 02)
> > 00:07.1 PCI bridge: Intel Corporation Alder Lake-P Thunderbolt 4 PCI Express
> > Root Port #1 (rev 02)
> > 00:07.2 PCI bridge: Intel Corporation Alder Lake-P Thunderbolt 4 PCI Express
> > Root Port #2 (rev 02)
> > 00:07.3 PCI bridge: Intel Corporation Alder Lake-P Thunderbolt 4 PCI Express
> > Root Port #3 (rev 02)
> > 00:08.0 System peripheral: Intel Corporation 12th Gen Core Processor
> > Gaussian & Neural Accelerator (rev 02)
> > 00:0a.0 Signal processing controller: Intel Corporation Platform Monitoring
> > Technology (rev 01)
> > 00:0d.0 USB controller: Intel Corporation Alder Lake-P Thunderbolt 4 USB
> > Controller (rev 02)
> > 00:0d.2 USB controller: Intel Corporation Alder Lake-P Thunderbolt 4 NHI #0
> > (rev 02)
> > 00:0d.3 USB controller: Intel Corporation Alder Lake-P Thunderbolt 4 NHI #1
> > (rev 02)
> > 00:14.0 USB controller: Intel Corporation Alder Lake PCH USB 3.2 xHCI Host
> > Controller (rev 01)
> > 00:14.2 RAM memory: Intel Corporation Alder Lake PCH Shared SRAM (rev 01)
> > 00:15.0 Serial bus controller: Intel Corporation Alder Lake PCH Serial IO
> > I2C Controller #0 (rev 01)
> > 00:15.1 Serial bus controller: Intel Corporation Alder Lake PCH Serial IO
> > I2C Controller #1 (rev 01)
> > 00:15.3 Serial bus controller: Intel Corporation Alder Lake PCH Serial IO
> > I2C Controller #3 (rev 01)
> > 00:16.0 Communication controller: Intel Corporation Alder Lake PCH HECI
> > Controller (rev 01)
> > 00:16.3 Serial controller: Intel Corporation Alder Lake AMT SOL Redirection
> > (rev 01)
> > 00:1d.0 PCI bridge: Intel Corporation Alder Lake PCI Express Root Port #9
> > (rev 01)
> > 00:1f.0 ISA bridge: Intel Corporation Alder Lake PCH eSPI Controller (rev
> > 01)
> > 00:1f.3 Audio device: Intel Corporation Alder Lake PCH-P High Definition
> > Audio Controller (rev 01)
> > 00:1f.4 SMBus: Intel Corporation Alder Lake PCH-P SMBus Host Controller (rev
> > 01)
> > 00:1f.5 Serial bus controller: Intel Corporation Alder Lake-P PCH SPI
> > Controller (rev 01)
> > 01:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD
> > Controller PM9C1a (DRAM-less)
> > 02:00.0 PCI bridge: Intel Corporation JHL6340 Thunderbolt 3 Bridge (C step)
> > [Alpine Ridge 2C 2016] (rev 02)
> > 03:01.0 PCI bridge: Intel Corporation JHL6340 Thunderbolt 3 Bridge (C step)
> > [Alpine Ridge 2C 2016] (rev 02)
> > 04:00.0 VGA compatible controller: NVIDIA Corporation GA102 [GeForce RTX
> > 3090] (rev a1)
> > 04:00.1 Audio device: NVIDIA Corporation GA102 High Definition Audio
> > Controller (rev a1)
> > 2b:00.0 PCI bridge: Intel Corporation Thunderbolt 4 Bridge [Goshen Ridge
> > 2020] (rev 03)
> > 2c:00.0 PCI bridge: Intel Corporation Thunderbolt 4 Bridge [Goshen Ridge
> > 2020] (rev 03)
> > 2c:01.0 PCI bridge: Intel Corporation Thunderbolt 4 Bridge [Goshen Ridge
> > 2020] (rev 03)
> > 2c:02.0 PCI bridge: Intel Corporation Thunderbolt 4 Bridge [Goshen Ridge
> > 2020] (rev 03)
> > 2c:03.0 PCI bridge: Intel Corporation Thunderbolt 4 Bridge [Goshen Ridge
> > 2020] (rev 03)
> > 2c:04.0 PCI bridge: Intel Corporation Thunderbolt 4 Bridge [Goshen Ridge
> > 2020] (rev 03)
> > 2e:00.0 PCI bridge: Intel Corporation JHL6340 Thunderbolt 3 Bridge (C step)
> > [Alpine Ridge 2C 2016] (rev 02)
> > 2f:01.0 PCI bridge: Intel Corporation JHL6340 Thunderbolt 3 Bridge (C step)
> > [Alpine Ridge 2C 2016] (rev 02)
> > 30:00.0 VGA compatible controller: NVIDIA Corporation GA102 [GeForce RTX
> > 3090] (rev a1)
> > 30:00.1 Audio device: NVIDIA Corporation GA102 High Definition Audio
> > Controller (rev a1)
> > 7d:00.0 PCI bridge: Intel Corporation JHL6340 Thunderbolt 3 Bridge (C step)
> > [Alpine Ridge 2C 2016] (rev 02)
> > 7e:01.0 PCI bridge: Intel Corporation JHL6340 Thunderbolt 3 Bridge (C step)
> > [Alpine Ridge 2C 2016] (rev 02)
> > 7f:00.0 VGA compatible controller: NVIDIA Corporation GA102 [GeForce RTX
> > 3090 Ti] (rev a1)
> > 7f:00.1 Audio device: NVIDIA Corporation GA102 High Definition Audio
> > Controller (rev a1)
> > a6:00.0 Ethernet controller: Intel Corporation Ethernet Controller I226-V
> > (rev 04)
> > 
> > 
> > /proc/iomem after connecting hub
> > 
> > 00000000-00000fff : Reserved
> > 00001000-0009efff : System RAM
> > 0009f000-000fffff : Reserved
> >   000a0000-000bffff : PCI Bus 0000:00
> >   000f0000-000fffff : System ROM
> > 00100000-3727bfff : System RAM
> > 3727c000-372cafff : Reserved
> > 372cb000-388b2fff : System RAM
> > 388b3000-388b3fff : Reserved
> > 388b4000-3b138fff : System RAM
> > 3b139000-3ba38fff : Reserved
> > 3ba39000-3d84efff : System RAM
> > 3d84f000-40a7efff : Reserved
> > 40a7f000-43a2efff : ACPI Non-volatile Storage
> >   43945000-43945fff : USBC000:00
> > 43a2f000-43afefff : ACPI Tables
> > 43aff000-43afffff : System RAM
> > 43b00000-47ffffff : Reserved
> > 49200000-493fffff : Reserved
> > 4a000000-503fffff : Reserved
> >   4c800000-503fffff : Graphics Stolen Memory
> > 50400000-bfffffff : PCI Bus 0000:00
> >   50400000-50400fff : 0000:00:1f.5
> >   50500000-507fffff : PCI Bus 0000:a6
> >     50500000-505fffff : 0000:a6:00.0
> >       50500000-505fffff : igc
> >     50600000-506fffff : 0000:a6:00.0
> >     50700000-50703fff : 0000:a6:00.0
> >       50700000-50703fff : igc
> >   52000000-5e1fffff : PCI Bus 0000:7d
> >     52000000-5e0fffff : PCI Bus 0000:7e
> >       52000000-5e0fffff : PCI Bus 0000:7f
> >         52000000-52ffffff : 0000:7f:00.0
> >           52000000-52ffffff : nvidia
> >         53000000-5307ffff : 0000:7f:00.0
> >         53080000-53083fff : 0000:7f:00.1
> >   60000000-6c1fffff : PCI Bus 0000:54
> >   6e000000-7a1fffff : PCI Bus 0000:2b
> >     6e000000-7a0fffff : PCI Bus 0000:2c
> >       6e000000-720fffff : PCI Bus 0000:2e
> >         6e000000-720fffff : PCI Bus 0000:2f
> >           6e000000-720fffff : PCI Bus 0000:30
> >             6e000000-6effffff : 0000:30:00.0
> >               6e000000-6effffff : nvidia
> >             6f000000-6f07ffff : 0000:30:00.0
> >             6f080000-6f083fff : 0000:30:00.1
> >   7a400000-7a4fffff : PCI Bus 0000:01
> >     7a400000-7a403fff : 0000:01:00.0
> >       7a400000-7a403fff : nvme
> >   7a600000-7a60ffff : 0000:00:14.0
> >     7a600000-7a60ffff : xhci-hcd
> >   7a611000-7a611fff : 0000:00:16.3
> >   7c000000-881fffff : PCI Bus 0000:02
> >     7c000000-880fffff : PCI Bus 0000:03
> >       7c000000-880fffff : PCI Bus 0000:04
> >         7c000000-7cffffff : 0000:04:00.0
> >           7c000000-7cffffff : nvidia
> >         7d000000-7d07ffff : 0000:04:00.0
> >         7d080000-7d083fff : 0000:04:00.1
> > c0000000-cfffffff : PCI ECAM 0000 [bus 00-ff]
> >   c0000000-cfffffff : PNP0C02:01
> > fd000000-fd68ffff : PNP0C02:02
> > fd690000-fd69ffff : INTC1055:00
> > fd6a0000-fd6affff : INTC1055:00
> > fd6b0000-fd6cffff : PNP0C02:02
> > fd6d0000-fd6dffff : INTC1055:00
> > fd6e0000-fd6effff : INTC1055:00
> > fd6f0000-fdffffff : PNP0C02:02
> > fe000000-fe01ffff : PNP0C02:02
> > fe04c000-fe04ffff : PNP0C02:02
> > fe050000-fe0affff : PNP0C02:02
> > fe0d0000-fe0fffff : PNP0C02:02
> > fe200000-fe7fffff : PNP0C02:02
> > fec00000-fec003ff : IOAPIC 0
> > fed00000-fed003ff : HPET 0
> >   fed00000-fed003ff : PNP0103:00
> > fed20000-fed7ffff : Reserved
> >   fed40000-fed44fff : NTC0702:00
> > fed90000-fed90fff : dmar0
> > fed91000-fed91fff : dmar1
> > feda0000-feda0fff : PNP0C02:01
> > feda1000-feda1fff : PNP0C02:01
> > fedc0000-fedc7fff : PNP0C02:01
> > fee00000-feefffff : PNP0C02:01
> > ff000000-ffffffff : PNP0C02:02
> > 100000000-10afbfffff : System RAM
> >   d6a000000-d6b1e52f7 : Kernel code
> >   d6b200000-d6b7a0fff : Kernel rodata
> >   d6b800000-d6bac0cff : Kernel data
> >   d6c247000-d6c30ffff : Kernel bss
> > 10afc00000-10afffffff : RAM buffer
> > 4000000000-7fffffffff : PCI Bus 0000:00
> >   4000000000-400fffffff : 0000:00:02.0
> >   4010000000-4016ffffff : 0000:00:02.0
> >   4017000000-4017000fff : 0000:00:15.0
> >     4017000000-40170001ff : lpss_dev
> >       4017000000-40170001ff : i2c_designware.0 lpss_dev
> >     4017000200-40170002ff : lpss_priv
> >     4017000800-4017000fff : idma64.0
> >   4017001000-4017001fff : 0000:00:15.1
> >     4017001000-40170011ff : lpss_dev
> >       4017001000-40170011ff : i2c_designware.1 lpss_dev
> >     4017001200-40170012ff : lpss_priv
> >     4017001800-4017001fff : idma64.1
> >   4017002000-4017002fff : 0000:00:15.3
> >     4017002000-40170021ff : lpss_dev
> >       4017002000-40170021ff : i2c_designware.2 lpss_dev
> >     4017002200-40170022ff : lpss_priv
> >     4017002800-4017002fff : idma64.2
> >   4020000000-40ffffffff : 0000:00:02.0
> >   6000000000-601bffffff : PCI Bus 0000:02
> >     6000000000-6011ffffff : PCI Bus 0000:03
> >       6000000000-6011ffffff : PCI Bus 0000:04
> >         6000000000-600fffffff : 0000:04:00.0
> >         6010000000-6011ffffff : 0000:04:00.0
> >   6020000000-603bffffff : PCI Bus 0000:2b
> >     6020000000-6031ffffff : PCI Bus 0000:2c
> >       6020000000-6031ffffff : PCI Bus 0000:2e
> >         6020000000-6031ffffff : PCI Bus 0000:2f
> >           6020000000-6031ffffff : PCI Bus 0000:30
> >             6020000000-602fffffff : 0000:30:00.0
> >             6030000000-6031ffffff : 0000:30:00.0
> >   6040000000-605bffffff : PCI Bus 0000:54
> >   605c000000-605cffffff : 0000:00:02.0
> >   605d000000-605d0fffff : 0000:00:1f.3
> >   605d100000-605d13ffff : 0000:00:0d.3
> >     605d100000-605d13ffff : thunderbolt
> >   605d140000-605d17ffff : 0000:00:0d.2
> >     605d140000-605d17ffff : thunderbolt
> >   605d180000-605d19ffff : 0000:00:04.0
> >     605d180000-605d19ffff : proc_thermal
> >   605d1a0000-605d1affff : 0000:00:0d.0
> >     605d1a0000-605d1affff : xhci-hcd
> >   605d1b0000-605d1b7fff : 0000:00:0a.0
> >   605d1b8000-605d1bbfff : 0000:00:1f.3
> >   605d1bc000-605d1bffff : 0000:00:14.2
> >   605d1c0000-605d1c00ff : 0000:00:1f.4
> >     605d1c0000-605d1c00ff : i801_smbus
> >   605d1c1000-605d1c1fff : 0000:00:16.0
> >     605d1c1000-605d1c1fff : mei_me
> >   605d1c5000-605d1c5fff : 0000:00:14.2
> >   605d1c6000-605d1c6fff : 0000:00:0d.3
> >   605d1c7000-605d1c7fff : 0000:00:0d.2
> >   605d1c8000-605d1c8fff : 0000:00:08.0
> >   6060000000-607bffffff : PCI Bus 0000:7d
> >     6060000000-6071ffffff : PCI Bus 0000:7e
> >       6060000000-6071ffffff : PCI Bus 0000:7f
> >         6060000000-606fffffff : 0000:7f:00.0
> >         6070000000-6071ffffff : 0000:7f:00.0
> > 
> >