[BUG] iwlwifi: Comet Lake PCH CNVi AX201 (8086:06f0) fails with error -110 on warm reboot

Hardware: Dell Precision 7550 (Comet Lake-H)
Wi-Fi: Intel Wi-Fi 6 AX201 / CNVi
PCI ID: 8086:06f0
Subsystem: 8086:0074

OS/Kernel:

Linux Mint 22.x
Ubuntu 24.04
Ubuntu 20.04 LTS (clean installation)
Kernel 7.0.0-28-generic
Kernel 6.14.x

Firmware:

Stock firmware
iwlwifi-QuZ-a0-hr-b0-77.ucode
iwlwifi-Qu-b0-hr-b0-77.ucode
Summary

The AX201 initializes normally after a complete cold boot, but fails to
re-initialize after a warm reboot, resume from sleep, or iwlwifi module
reload.

The failure consistently occurs during the early PCIe/CNVi initialization,
around CSR_RESET and Host Monitor polling, before the driver reaches the
firmware loading stage.

The resulting error is:

iwlwifi 0000:00:14.3: probe with driver iwlwifi failed with error -110
Kernel log
[  609.416668] iwlwifi 0000:00:14.3: Host monitor block 0x0 vector 0x6
[  609.416670] iwlwifi 0000:00:14.3:     value [iter 0]: 0x00000003
...
[  609.416695] iwlwifi 0000:00:14.3: Host monitor block 0x22 vector 0x0
[  609.416714] iwlwifi 0000:00:14.3:     value [iter 0]: 0x00000003
[  609.422051] iwlwifi 0000:00:14.3: probe with driver iwlwifi failed with
error -110

Steps to reproduce

   1. Perform a complete cold boot.
   2. Confirm that the AX201 initializes and Wi-Fi works normally.
   3. Remove and reload the driver:
   4. sudo modprobe -r iwlwifi
   5. sudo modprobe iwlwifi
   6. The driver fails to probe and returns -110.
   7. The same behavior occurs after a warm reboot and after resume from
   sleep.


What has been tested;

   - Upstream firmware revision 77 - no change.
   - Both Qu-b0 and QuZ-a0 revision 77 firmware files tested.
   - pcie_aspm=off - no change.
   - iwlwifi.power_save=0 - no change.
   - Intel AMT / Manageability disabled in BIOS.
   - POST Fastboot set to Thorough.
   - Clean Ubuntu 20.04 LTS installation - same warm-reboot/module-reload
   failure.
   - Linux Mint and Fedora - same behavior.


A complete cold power-on consistently allows the initial probe to succeed,
while reinitialization without removing power results in the -110 timeout.

Firmware loading
The firmware revision does not appear to affect the failure.
The timeout occurs during the initial bus/reset handling and Host Monitor
polling, before the driver reaches the point where it requests the
microcode. Because of this, changing the firmware version or location does
not change the observed behavior.

Additional information

The system is a dedicated Linux installation with no Windows dual-boot or
Fast Startup involved.
Full dmesg, lshw, and Intel SSU output are attached.
The behavior appears consistent with a failure to properly reset or
reinitialize the CNVi device after a warm reset/power-state transition. I'm
not sure whether this points specifically to D3cold handling or reset
sequencing, so I've included the logs and hardware information for further
investigation.
Please let me know if any additional register dumps, PCI
configuration-space data, or specific kernel debugging output would be
useful.

Thanks,
Mark