I have laptop with an Intel AX200 Wi-Fi controller and everything works fine in a 5.14 kernel, but in 5.15 or later, the adapter does not work most of the time. In maybe 9 out of 10 boots in 5.15+, the wlan0 interface does not get created. The hardware is detected and shows up in lspci, the iwlwifi driver is loaded, but no interface is created. I bisected the issue to this commit: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=75ae663d053bddf7c70a24cccf53c83ae03deff8 This adds a call to rtnl_lock() that should have been included in this commit: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=eb09ae93dabfd0980f5226dfd0bd531eb87902f5 If I remove the call to rtnl_lock and rtnl_unlock added in those commits from 5.17.0-rc4, everything works again (but dmesg has a bunch of RTNL assertion failures from the missing lock). I assume there is a race or deadlock somewhere, but I've not been able to find it. I'm not at all familiar with this part of the kernel so perhaps that's not surprising :-) Any thoughts as to what might be going wrong or suggestions on further debugging? dmesg when in broken state: $ grep iwl dmesg-broken [ 6.358897] iwlwifi 0000:02:00.0: enabling device (0000 -> 0002) [ 6.377120] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi- cc-a0-69.ucode failed with error -2 [ 6.388252] iwlwifi 0000:02:00.0: api flags index 2 larger than supported by driver [ 6.389455] iwlwifi 0000:02:00.0: TLV_FW_FSEQ_VERSION: FSEQ Version: 89.3.35.37 [ 6.391887] iwlwifi 0000:02:00.0: loaded firmware version 68.01d30b0c.0 cc-a0-68.ucode op_mode iwlmvm [ 6.732076] iwlwifi 0000:02:00.0: Detected Intel(R) Wi-Fi 6 AX200 160MHz, REV=0x340 [ 6.856276] iwlwifi 0000:02:00.0: Detected RF HR B3, rfid=0x10a100 [ 6.920917] iwlwifi 0000:02:00.0: base HW address: 78:2b:46:4a:b4:97 Kernel config: $ grep -i iwl .config # CONFIG_IWL4965 is not set # CONFIG_IWL3945 is not set CONFIG_IWLWIFI=m CONFIG_IWLWIFI_LEDS=y # CONFIG_IWLDVM is not set CONFIG_IWLMVM=m CONFIG_IWLWIFI_OPMODE_MODULAR=y CONFIG_IWLWIFI_DEBUG=y Thanks, Robert
