AX200 Microcode SW error on Linux kernel 6.6 LTS with firmware cc-a0-77.ucode

[y_satou70]

We are seeing intermittent "Microcode SW error detected. Restarting 0x0" repeatedly with our Linux system, that causes intermittent network down.

We tested with the latest Linux kernel 6.6 LTS (LongTermSupport) branch (6.6.93), and the latest cc-a0-77.ucode firmware/microcode  (firmware version: 77.864baa2e.0).

This event's frequency is pretty high - one of our stations got this event every few minutes:

[Mon Jun 9 02:01:40 2025] iwlwifi 0000:02:00.0: Microcode SW error detected. Restarting 0x0.
[Mon Jun 9 02:05:36 2025] iwlwifi 0000:02:00.0: Microcode SW error detected. Restarting 0x0.
[Mon Jun 9 02:14:36 2025] iwlwifi 0000:02:00.0: Microcode SW error detected. Restarting 0x0.
[Mon Jun 9 02:17:33 2025] iwlwifi 0000:02:00.0: Microcode SW error detected. Restarting 0x0.
[Mon Jun 9 02:28:24 2025] iwlwifi 0000:02:00.0: Microcode SW error detected. Restarting 0x0.
[Mon Jun 9 02:34:50 2025] iwlwifi 0000:02:00.0: Microcode SW error detected. Restarting 0x0.
[Mon Jun 9 02:42:13 2025] iwlwifi 0000:02:00.0: Microcode SW error detected. Restarting 0x0.
[Mon Jun 9 02:42:15 2025] iwlwifi 0000:02:00.0: Microcode SW error detected. Restarting 0x0.
[Mon Jun 9 02:49:24 2025] iwlwifi 0000:02:00.0: Microcode SW error detected. Restarting 0x0.
[Mon Jun 9 03:00:41 2025] iwlwifi 0000:02:00.0: Microcode SW error detected. Restarting 0x0.
[Mon Jun 9 03:07:22 2025] iwlwifi 0000:02:00.0: Microcode SW error detected. Restarting 0x0.
[Mon Jun 9 03:09:59 2025] iwlwifi 0000:02:00.0: Microcode SW error detected. Restarting 0x0.
[Mon Jun 9 03:13:59 2025] iwlwifi 0000:02:00.0: Microcode SW error detected. Restarting 0x0.
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: Microcode SW error detected. Restarting 0x0.

Here is the kernel log output:

[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: Microcode SW error detected. Restarting 0x0.
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: Start IWL Error Log Dump:
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: Transport status: 0x0000004A, valid: 6
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: Loaded firmware version: 77.864baa2e.0 cc-a0-77.ucode
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x000028AD | ADVANCED_SYSASSERT
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x000022F0 | trm_hw_status0
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000000 | trm_hw_status1
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x004F8D82 | branchlink2
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x000019CC | interruptlink1
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x000019CC | interruptlink2
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x0000002C | data1
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0xDEADBEEF | data2
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0xDEADBEEF | data3
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x0580C4BB | beacon time
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x5B616B55 | tsf low
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00002EF2 | tsf hi
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000000 | time gp1
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x158F2EA5 | time gp2
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000001 | uCode revision type
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x0000004D | uCode version major
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x864BAA2E | uCode version minor
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000340 | hw version
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x18C89000 | board version
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x0000001C | hcmd
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x62E20000 | isr0
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x01400000 | isr1
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x08F00002 | isr2
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00C3400F | isr3
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000000 | isr4
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00BD0103 | last cmd Id
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x0000E7C4 | wait_event
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000000 | l2p_control
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000000 | l2p_duration
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x0000003F | l2p_mhvalid
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000000 | l2p_addr_match
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000009 | lmpm_pmg_sel
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000000 | timestamp
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x0000B8B8 | flow_handler
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: Start IWL Error Log Dump:
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: Transport status: 0x0000004A, valid: 7
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x20000070 | NMI_INTERRUPT_LMAC_FATAL
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000000 | umac branchlink1
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x80455D7A | umac branchlink2
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x8047300E | umac interruptlink1
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x8047300E | umac interruptlink2
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000400 | umac data1
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x8047300E | umac data2
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000000 | umac data3
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x0000004D | umac major
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x864BAA2E | umac minor
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x158F2EC5 | frame pointer
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0xC0886260 | stack pointer
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00C7010D | last host cmd
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000000 | isr status reg
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: IML/ROM dump:
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000003 | IML/ROM error/state
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x000057EB | IML/ROM data1
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000080 | IML/ROM WFPM_AUTH_KEY_0
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: Fseq Registers:
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x60000000 | FSEQ_ERROR_CODE
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x80290021 | FSEQ_TOP_INIT_VERSION
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00050008 | FSEQ_CNVIO_INIT_VERSION
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x0000A503 | FSEQ_OTP_VERSION
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x80000003 | FSEQ_TOP_CONTENT_VERSION
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x4552414E | FSEQ_ALIVE_TOKEN
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00100530 | FSEQ_CNVI_ID
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000532 | FSEQ_CNVR_ID
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00100530 | CNVI_AUX_MISC_CHIP
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000532 | CNVR_AUX_MISC_CHIP
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x05B0905B | CNVR_SCU_SD_REGS_SD_REG_DIG_DCDC_VTRIM
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x0000025B | CNVR_SCU_SD_REGS_SD_REG_ACTIVE_VDIG_MIRROR
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00050008 | FSEQ_PREV_CNVIO_INIT_VERSION
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00290021 | FSEQ_WIFI_FSEQ_VERSION
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x69584D94 | FSEQ_BT_FSEQ_VERSION
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: 0x00000104 | FSEQ_CLASS_TP_VERSION
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: UMAC CURRENT PC: 0x80472b1c
[Mon Jun 9 03:20:01 2025] iwlwifi 0000:02:00.0: LMAC1 CURRENT PC: 0xd0
[Mon Jun 9 03:20:01 2025] ieee80211 phy4: Hardware restart was requested

[y_satou70]

If you need tracelog or debug dump for analysis, (https://wireless.docs.kernel.org/en/latest/en/users/drivers/iwlwifi/debugging.html), please let me know.

[y_satou70]

This is also happened with current latest stable kernel 6.15 - so moved to Kernel bugzilla https://bugzilla.kernel.org/show_bug.cgi?id=216351

[y_satou70]

requested to open fresh case in Kernel bugzilla, with closing old https://bugzilla.kernel.org/show_bug.cgi?id=216351

submitted fresh new bug report as https://bugzilla.kernel.org/show_bug.cgi?id=220300