Re: iwlwifi Lockdep warning with 5.12-rc4 on 8086:02f0 (Comet Lake PCH-LP CNVi WiFi)

[Hans de Goede <hdegoede@redhat.com>]

Hi Chris,

On 4/13/21 11:38 PM, Chris Murphy wrote:
> On Tue, Apr 13, 2021 at 2:55 PM Hans de Goede <hdegoede@redhat.com> wrote:
>>
>> Hi All,
>>
>> I'm seeing the following lockdep warning with 5.12-rc4 on 8086:02f0 (Comet Lake PCH-LP CNVi WiFi):
>>
>> [   29.923811] Bluetooth: hci0: Waiting for firmware download to complete
>> [   29.925068] Bluetooth: hci0: Firmware loaded in 1912613 usecs
>> [   29.925326] Bluetooth: hci0: Waiting for device to boot
>> [   29.940698] Bluetooth: hci0: Device booted in 15258 usecs
>> [   29.943517] Bluetooth: hci0: Found Intel DDC parameters: intel/ibt-19-0-4.ddc
>> [   29.945681] Bluetooth: hci0: Applying Intel DDC parameters completed
>> [   29.948684] Bluetooth: hci0: Firmware revision 0.0 build 121 week 7 2021
>> [   30.008640] Bluetooth: hci0: MSFT filter_enable is already on
>> [   30.087338] ------------[ cut here ]------------
>> [   30.087356] WARNING: CPU: 5 PID: 1481 at kernel/softirq.c:178 __local_bh_enable_ip+0x97/0xd0
>> [   30.087360] Modules linked in: cmac bnep snd_ctl_led snd_soc_skl_hda_dsp(E) snd_soc_hdac_hdmi(E) snd_soc_dmic(E) snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_sof_pci_intel_cnl snd_sof_intel_hda_common vfat fat iTCO_wdt mei_wdt snd_soc_hdac_hda(E) mei_hdcp intel_pmc_bxt soundwire_intel iTCO_vendor_support soundwire_generic_allocation soundwire_cadence snd_sof_intel_hda snd_sof_pci snd_sof intel_rapl_msr x86_pkg_temp_thermal intel_powerclamp coretemp snd_sof_xtensa_dsp snd_soc_skl kvm_intel snd_soc_sst_ipc(E) snd_soc_sst_dsp(E) snd_hda_ext_core(E) snd_soc_acpi_intel_match(E) snd_soc_acpi kvm snd_soc_core cdc_ether irqbypass usbnet snd_compress rapl r8152 ac97_bus intel_cstate snd_pcm_dmaengine mii snd_hda_intel intel_uncore snd_intel_dspcfg(E) snd_intel_sdw_acpi(E) snd_hda_codec snd_usb_audio snd_hda_core(E) snd_usbmidi_lib snd_hwdep iwlmvm snd_rawmidi snd_seq pcspkr snd_seq_device mac80211 snd_pcm wmi_bmof i2c_i801 uvcvideo intel_wmi_thunderbolt e1000e i2c_smbus
>> [   30.087436]  btusb snd_timer videobuf2_vmalloc btrtl thunderbolt videobuf2_memops libarc4 btbcm btintel videobuf2_v4l2 bluetooth videobuf2_common iwlwifi videodev mei_me processor_thermal_device processor_thermal_rfim ecdh_generic joydev mc mei processor_thermal_mbox ecc processor_thermal_rapl cfg80211 idma64 intel_rapl_common ucsi_acpi intel_pch_thermal intel_soc_dts_iosf nxp_nci_i2c typec_ucsi nxp_nci nci roles typec nfc int3403_thermal int340x_thermal_zone soc_button_array intel_hid int3400_thermal acpi_thermal_rel sparse_keymap acpi_pad binfmt_misc zram ip_tables dm_crypt trusted hid_logitech_hidpp hid_logitech_dj uas usb_storage crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel i915 serio_raw nvme i2c_algo_bit nvme_core drm_kms_helper cec hid_multitouch drm wmi i2c_hid_acpi i2c_hid thinkpad_acpi ledtrig_audio platform_profile snd soundcore rfkill drm_privacy_screen_helper video pinctrl_cannonlake i2c_dev fuse
>> [   30.087509] CPU: 5 PID: 1481 Comm: NetworkManager Tainted: G            E     5.12.0-rc4+ #272
>> [   30.087511] Hardware name: LENOVO 20U90SIT19/20U90SIT19, BIOS N2WET24W (1.14 ) 10/15/2020
>> [   30.087512] RIP: 0010:__local_bh_enable_ip+0x97/0xd0
>> [   30.087514] Code: f2 45 a9 00 ff ff 00 74 36 65 ff 0d 33 d7 f2 45 e8 2e 2c 13 00 fb 66 0f 1f 44 00 00 5b 5d c3 65 8b 05 59 df f2 45 85 c0 75 9c <0f> 0b eb 98 e8 50 2b 13 00 eb a7 48 89 ef e8 76 28 07 00 eb b0 65
>> [   30.087516] RSP: 0018:ffffbc1240e471b0 EFLAGS: 00010046
>> [   30.087518] RAX: 0000000000000000 RBX: 0000000000000201 RCX: 0000000000000000
>> [   30.087520] RDX: 0000000000000003 RSI: 0000000000000201 RDI: ffffffffc0bd54db
>> [   30.087521] RBP: ffffffffc0bd54db R08: 0000000000000000 R09: 0000000000000001
>> [   30.087522] R10: ffffbc1240e470a0 R11: 0000000000000001 R12: ffff9817c578ac10
>> [   30.087523] R13: 0000000000000000 R14: 0000000080000000 R15: 0000000000000000
>> [   30.087525] FS:  00007f308dbbdbc0(0000) GS:ffff981b1a540000(0000) knlGS:0000000000000000
>> [   30.087526] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [   30.087528] CR2: 00007f659c013038 CR3: 00000001420bc002 CR4: 00000000003706e0
>> [   30.087529] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>> [   30.087530] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>> [   30.087531] Call Trace:
>> [   30.087534]  iwl_pcie_gen2_enqueue_hcmd+0x56b/0x8c0 [iwlwifi]
>> [   30.087551]  iwl_trans_txq_send_hcmd+0x59/0x470 [iwlwifi]
>> [   30.087564]  iwl_trans_send_cmd+0x81/0x180 [iwlwifi]
>> [   30.087572]  ? lock_acquire+0xe2/0x3b0
>> [   30.087576]  iwl_mvm_send_cmd+0x28/0x80 [iwlmvm]
>> [   30.087587]  iwl_mvm_led_set+0x9c/0xc0 [iwlmvm]
>> [   30.087600]  ? _raw_read_lock_irqsave+0x7f/0xa0
>> [   30.087602]  ? _raw_read_lock_irqsave+0x88/0xa0
>> [   30.087605]  led_trigger_event+0x46/0x70
>> [   30.087609]  ieee80211_do_open+0x4c2/0xa70 [mac80211]
>> [   30.087642]  ieee80211_open+0x69/0x90 [mac80211]
>> [   30.087666]  __dev_open+0xe5/0x1b0
>> [   30.087670]  __dev_change_flags+0x1c8/0x240
>> [   30.087676]  dev_change_flags+0x21/0x60
>> [   30.087682]  do_setlink+0x2a9/0x1290
>> [   30.087690]  ? __lock_acquire+0x389/0x1e10
>> [   30.087707]  ? lock_is_held_type+0xa5/0x120
>> [   30.087713]  __rtnl_newlink+0x66d/0xa20
>> [   30.087753]  rtnl_newlink+0x44/0x70
>> [   30.087756]  rtnetlink_rcv_msg+0x181/0x4b0
>> [   30.087761]  ? rtnetlink_put_metrics+0x1e0/0x1e0
>> [   30.087763]  netlink_rcv_skb+0x5b/0x100
>> [   30.087769]  netlink_unicast+0x175/0x240
>> [   30.087773]  netlink_sendmsg+0x24d/0x480
>> [   30.087779]  sock_sendmsg+0x5e/0x60
>> [   30.087782]  ____sys_sendmsg+0x25b/0x2a0
>> [   30.087784]  ? import_iovec+0x17/0x20
>> [   30.087790]  ___sys_sendmsg+0xa3/0xf0
>> [   30.087804]  __sys_sendmsg+0x73/0xb0
>> [   30.087811]  do_syscall_64+0x33/0x40
>> [   30.087815]  entry_SYSCALL_64_after_hwframe+0x44/0xae
>> [   30.087817] RIP: 0033:0x7f308eca96fd
>> [   30.087819] Code: 28 89 54 24 1c 48 89 74 24 10 89 7c 24 08 e8 fa ee ff ff 8b 54 24 1c 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 33 44 89 c7 48 89 44 24 08 e8 4e ef ff ff 48
>> [   30.087820] RSP: 002b:00007fff70b4af40 EFLAGS: 00000293 ORIG_RAX: 000000000000002e
>> [   30.087823] RAX: ffffffffffffffda RBX: 0000000000000014 RCX: 00007f308eca96fd
>> [   30.087824] RDX: 0000000000000000 RSI: 00007fff70b4af80 RDI: 000000000000000c
>> [   30.087825] RBP: 0000565535afe030 R08: 0000000000000000 R09: 0000000000000000
>> [   30.087826] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
>> [   30.087827] R13: 00007fff70b4b0e0 R14: 00007fff70b4b0dc R15: 0000000000000000
>> [   30.087835] irq event stamp: 242153
>> [   30.087836] hardirqs last  enabled at (242151): [<ffffffffba0ea692>] __local_bh_enable_ip+0x82/0xd0
>> [   30.087838] hardirqs last disabled at (242152): [<ffffffffbad3f794>] _raw_read_lock_irqsave+0x94/0xa0
>> [   30.087840] softirqs last  enabled at (242150): [<ffffffffc0bd54db>] iwl_pcie_gen2_enqueue_hcmd+0x56b/0x8c0 [iwlwifi]
>> [   30.087850] softirqs last disabled at (242153): [<ffffffffc0bd505b>] iwl_pcie_gen2_enqueue_hcmd+0xeb/0x8c0 [iwlwifi]
>> [   30.087857] ---[ end trace aa0b171b4415a1fe ]---
>>
> 
> 
> Looks like this:
> https://lore.kernel.org/linux-wireless/nycvar.YFH.7.76.2103021125430.12405@cbobk.fhfr.pm/
> 
> I tested that patch on rc6 and it worked so far.

That patch has been added to rc7, so I tested rc7 and rc7 still has the lockdep splat in dmesg.

But good news, the issue is my wifi card uses iwl_pcie_gen2_enqueue_hcmd where as the
patch you linked to fixes iwl_pcie_enqueue_hcmd . Applying the same changes to the
iwl_pcie_gen2_enqueue_hcmd function also fixes lockdep complaining for me.

I'll submit a patch for this upstream right away.

Regards,

Hans