Arch Linux

rptynan

Member

Registered: 2012-10-07

Posts: 9

Wifi causing errors in dmesg

Hi,

I recently got a new laptop (Dell XPS 13, 9333) and installed archlinux on it. For a while, everything was running well, until recently, when my dmesg started showing lots of crash messages (multiple a minute when it's at its height) and other wireless interface messages.

I think the problem either began when I ran an update a few weeks ago, or alternatively, when I starting using a new wifi network (eduroam, at my uni, which is the network this is currently happening on).

So firstly, we have these kernel errors:

[ 4331.883184] ------------[ cut here ]------------
[ 4331.883224] WARNING: CPU: 2 PID: 4335 at net/wireless/reg.c:1806 reg_process_hint+0x2d1/0x460 [cfg80211]()
[ 4331.883254] Modules linked in: fuse ctr ccm rfcomm bnep ecb uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common videodev btusb hid_multitouch media hid_generic bluetooth usbhid snd_hda_codec_hdmi dell_wmi sparse_keymap joydev mousedev arc4 hid_rmi iTCO_wdt iTCO_vendor_support nls_iso8859_1 nls_cp437 vfat dell_laptop fat coretemp hwmon intel_rapl dcdbas x86_pkg_temp_thermal intel_powerclamp kvm_intel kvm iwlmvm crct10dif_pclmul crc32_pclmul crc32c_intel mac80211 ghash_clmulni_intel aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd iwlwifi rtc_efi evdev pcspkr psmouse mac_hid serio_raw cfg80211 i2c_i801 rfkill thermal wmi snd_hda_codec_realtek snd_hda_codec_generic i2c_hid i915 hid drm_kms_helper snd_hda_intel snd_hda_controller drm gpio_lynxpoint dw_dmac video dw_dmac_core
[ 4331.883327]  snd_hda_codec 8250_dw i2c_designware_platform spi_pxa2xx_platform i2c_designware_core snd_hwdep intel_gtt mei_me snd_pcm tpm_tis i2c_algo_bit i2c_core snd_timer battery mei tpm ac snd lpc_ich button soundcore shpchp processor sch_fq_codel ext4 crc16 mbcache jbd2 sd_mod crc_t10dif crct10dif_common atkbd libps2 ehci_pci xhci_hcd ehci_hcd ahci libahci libata scsi_mod usbcore usb_common sdhci_acpi sdhci i8042 led_class serio mmc_core
[ 4331.883373] CPU: 2 PID: 4335 Comm: kworker/2:0 Tainted: G        W      3.17.2-1-ARCH #1
[ 4331.883376] Hardware name: Dell Inc. XPS13 9333/0D13CR, BIOS A04 03/19/2014
[ 4331.883388] Workqueue: events reg_todo [cfg80211]
[ 4331.883391]  0000000000000000 0000000017df5c13 ffff8801c4073d58 ffffffff815367d0
[ 4331.883396]  0000000000000000 ffff8801c4073d90 ffffffff8107054d ffff8800d6441a40
[ 4331.883400]  ffff88020f5a0260 ffff8800d6441a5c 0000000000000000 ffff88021f298000
[ 4331.883404] Call Trace:
[ 4331.883413]  [<ffffffff815367d0>] dump_stack+0x4d/0x6f
[ 4331.883420]  [<ffffffff8107054d>] warn_slowpath_common+0x7d/0xa0
[ 4331.883426]  [<ffffffff8107067a>] warn_slowpath_null+0x1a/0x20
[ 4331.883437]  [<ffffffffa063d3b1>] reg_process_hint+0x2d1/0x460 [cfg80211]
[ 4331.883450]  [<ffffffffa063d5b9>] reg_todo+0x79/0x1a0 [cfg80211]
[ 4331.883462]  [<ffffffff81088b85>] process_one_work+0x145/0x400
[ 4331.883467]  [<ffffffff8108914b>] worker_thread+0x6b/0x4a0
[ 4331.883472]  [<ffffffff810890e0>] ? init_pwq.part.22+0x10/0x10
[ 4331.883476]  [<ffffffff8108e06a>] kthread+0xea/0x100
[ 4331.883482]  [<ffffffff811c0000>] ? hwpoison_filter+0x160/0x1b0
[ 4331.883486]  [<ffffffff8108df80>] ? kthread_create_on_node+0x1b0/0x1b0
[ 4331.883491]  [<ffffffff8153c6fc>] ret_from_fork+0x7c/0xb0
[ 4331.883495]  [<ffffffff8108df80>] ? kthread_create_on_node+0x1b0/0x1b0
[ 4331.883498] ---[ end trace b5965dd6bfb33ac1 ]---

And then along with that, I see a lot of these messages (many in a small period usually), especially while on battery, or just after a crash. Wifi speed and reliability seem to suffer when these errors are being given:

[ 4606.324785] wlp2s0: Limiting TX power to 17 (20 - 3) dBm as advertised by 02:18:4a:a5:9d:41
[ 4609.285630] wlp2s0: Limiting TX power to 14 (20 - 6) dBm as advertised by 02:18:4a:a5:9d:41
[ 4816.917858] wlp2s0: Limiting TX power to 17 (20 - 3) dBm as advertised by 02:18:4a:a5:9d:41
[ 4819.743625] wlp2s0: Limiting TX power to 14 (20 - 6) dBm as advertised by 02:18:4a:a5:9d:41

As for my setup, lspci shows my wifi card:

02:00.0 Network controller: Intel Corporation Wireless 7260 (rev 6b)

I have the iw package installed for the card and I'm currently using network-manager-applet for connecting to wifi (which is what I used to setup  eduroam). I'm also running the latest kernel (3.17.2-1-ARCH) and are fully up to date with arch repos.

I've tried to look around, but am really stuck on this one, can anyone help?

Thanks

Wey

Member

Registered: 2011-04-22

Posts: 217

Re: Wifi causing errors in dmesg

Hi, i had the same error message with eduroam. I checked journalctl and also saw "wpa_supplicant[523]: OpenSSL: tls_connection_ca_cert - Failed to load root certificates error:02001002:system library:fopen:No such file or directory". So in the network manager applet I selected /etc/ssl/certs/ca-certificates.crt and now it works again.

rptynan

Member

Registered: 2012-10-07

Posts: 9

Re: Wifi causing errors in dmesg

Selecting those certificates causes my wifi speed to slow down immensely (around 10KB/s) although I didn't get those same errors in my journal so we mightn't have the same problem.
Thanks for the suggestion though.

Updates, during the last kernel upgrade, the connection was flawless for a while, but after running the last pacman update, it's gone back to how it was. I'm considering rolling back the kernel and checking whatever packages were updated.

Vain

Member

Registered: 2008-10-19

Posts: 183

Re: Wifi causing errors in dmesg

There’s a related bug report including a link to the upstream report:

https://bugs.archlinux.org/task/41906

btw: This is just a warning, not a crash, right? Can anybody tell if this warning is important? I, too, see it sometimes, but I don’t experience any problems that are directly related to that warning. I’m referreing to the “reg_process_hint” stuff.

rptynan

Member

Registered: 2012-10-07

Posts: 9

Re: Wifi causing errors in dmesg

That looks to be the same as what's happening to mine, as it also tends to happen after a resume from suspend, especially after updating to 3.17.4 kernel.

I don't know if that message is just a warning, but when it occurs my wifi connection definitely crawls to a halt. So whether they're directly related or caused by the same thing, I'm not sure.