Created attachment 282333
full dmesg log

With kernels 5.1.0-rc I noticed these microcode errors when working via NFS. Testing with kernel 5.0 didn't reproduce it. I wasn't able getting a coredump as described in https://wireless.wiki.kernel.org/en/users/drivers/iwlwifi/debugging, cause /sys/kernel/debug/iwlwifi does not exist on my system.

error in dmesg log:

[43837.111256] iwlwifi 0000:02:00.0: Microcode SW error detected.  Restarting 0x2000000.
[43837.111554] iwlwifi 0000:02:00.0: Start IWL Error Log Dump:
[43837.111559] iwlwifi 0000:02:00.0: Status: 0x00000100, count: 6
[43837.111562] iwlwifi 0000:02:00.0: Loaded firmware version: 36.9f0a2d68.0
[43837.111567] iwlwifi 0000:02:00.0: 0x00000EDC | ADVANCED_SYSASSERT          
[43837.111570] iwlwifi 0000:02:00.0: 0x00000280 | trm_hw_status0
[43837.111573] iwlwifi 0000:02:00.0: 0x00000000 | trm_hw_status1
[43837.111577] iwlwifi 0000:02:00.0: 0x00024180 | branchlink2
[43837.111580] iwlwifi 0000:02:00.0: 0x000397EA | interruptlink1
[43837.111583] iwlwifi 0000:02:00.0: 0x00000000 | interruptlink2
[43837.111586] iwlwifi 0000:02:00.0: 0x0AEA001C | data1
[43837.111590] iwlwifi 0000:02:00.0: 0x20000606 | data2
[43837.111593] iwlwifi 0000:02:00.0: 0x00001E98 | data3
[43837.111596] iwlwifi 0000:02:00.0: 0xB641033D | beacon time
[43837.111598] iwlwifi 0000:02:00.0: 0xF5DE7CC6 | tsf low
[43837.111601] iwlwifi 0000:02:00.0: 0x00000644 | tsf hi
[43837.111604] iwlwifi 0000:02:00.0: 0x00000000 | time gp1
[43837.111607] iwlwifi 0000:02:00.0: 0x32EE2608 | time gp2
[43837.111610] iwlwifi 0000:02:00.0: 0x00000001 | uCode revision type
[43837.111614] iwlwifi 0000:02:00.0: 0x00000024 | uCode version major
[43837.111617] iwlwifi 0000:02:00.0: 0x9F0A2D68 | uCode version minor
[43837.111619] iwlwifi 0000:02:00.0: 0x00000201 | hw version
[43837.111622] iwlwifi 0000:02:00.0: 0x00489008 | board version
[43837.111625] iwlwifi 0000:02:00.0: 0x20000606 | hcmd
[43837.111627] iwlwifi 0000:02:00.0: 0x20022002 | isr0
[43837.111630] iwlwifi 0000:02:00.0: 0x00000000 | isr1
[43837.111633] iwlwifi 0000:02:00.0: 0x0800180A | isr2
[43837.111636] iwlwifi 0000:02:00.0: 0x00416CC1 | isr3
[43837.111638] iwlwifi 0000:02:00.0: 0x00000000 | isr4
[43837.111640] iwlwifi 0000:02:00.0: 0x0AC6001C | last cmd Id
[43837.111643] iwlwifi 0000:02:00.0: 0x00000000 | wait_event
[43837.111645] iwlwifi 0000:02:00.0: 0x00004288 | l2p_control
[43837.111648] iwlwifi 0000:02:00.0: 0x00018024 | l2p_duration
[43837.111650] iwlwifi 0000:02:00.0: 0x00000000 | l2p_mhvalid
[43837.111653] iwlwifi 0000:02:00.0: 0x000000E7 | l2p_addr_match
[43837.111655] iwlwifi 0000:02:00.0: 0x0000000D | lmpm_pmg_sel
[43837.111658] iwlwifi 0000:02:00.0: 0x04120134 | timestamp
[43837.111660] iwlwifi 0000:02:00.0: 0x00006078 | flow_handler
[43837.111734] iwlwifi 0000:02:00.0: Start IWL Error Log Dump:
[43837.111738] iwlwifi 0000:02:00.0: Status: 0x00000100, count: 7
[43837.111741] iwlwifi 0000:02:00.0: 0x00000070 | NMI_INTERRUPT_LMAC_FATAL
[43837.111744] iwlwifi 0000:02:00.0: 0x00000000 | umac branchlink1
[43837.111747] iwlwifi 0000:02:00.0: 0xC0086AA4 | umac branchlink2
[43837.111750] iwlwifi 0000:02:00.0: 0xC0083C90 | umac interruptlink1
[43837.111752] iwlwifi 0000:02:00.0: 0xC0083C90 | umac interruptlink2
[43837.111755] iwlwifi 0000:02:00.0: 0x00000800 | umac data1
[43837.111758] iwlwifi 0000:02:00.0: 0xC0083C90 | umac data2
[43837.111760] iwlwifi 0000:02:00.0: 0xDEADBEEF | umac data3
[43837.111763] iwlwifi 0000:02:00.0: 0x00000024 | umac major
[43837.111766] iwlwifi 0000:02:00.0: 0x9F0A2D68 | umac minor
[43837.111769] iwlwifi 0000:02:00.0: 0xC088628C | frame pointer
[43837.111772] iwlwifi 0000:02:00.0: 0xC088628C | stack pointer
[43837.111774] iwlwifi 0000:02:00.0: 0x0061014E | last host cmd
[43837.111777] iwlwifi 0000:02:00.0: 0x00000000 | isr status reg
[43837.111783] ieee80211 phy0: Hardware restart was requested
[43837.606032] iwlwifi 0000:02:00.0: Failing on timeout while stopping DMA channel 8 [0x07fd0001]