Comment # 8 on bug 1199922 from Takashi Iwai

The log shows like:

[  648.560086] BTRFS info (device nvme0n1p4): qgroup scan completed
(inconsistency flag cleared)
[ 1680.662985] pcieport 0000:00:01.2: pciehp: Slot(0): Link Down
[ 1680.662995] pcieport 0000:00:01.2: pciehp: Slot(0): Card not present
[ 1680.728731] ------------[ cut here ]------------
[ 1680.728731] Timeout waiting for hardware access (CSR_GP_CNTRL 0xffffffff)
[ 1680.728731] WARNING: CPU: 5 PID: 103 at
drivers/net/wireless/intel/iwlwifi/pcie/trans.c:2118
__iwl_trans_pcie_grab_nic_access+0x1ec/0x220 [iwlwifi]

... then starts breaking the iwlwifi stuff.

It implies that the PCI-e hotplug is, by some reason, disconnected.  There is
no event shown between 648 and 1680 sec, so I can't judge what happened there
at all.

Did you do anything special at that moment?  And is the issue reproducible?
Moreover, is this a regression from previous releases?

In anyway, if the problem is reproducible, we may get more information.