I have a Dell m5510 & my Anker 7221 bluetooth keyboard keeps getting
disconnected after a while. Looking at log file and I found it's crashing (not
the laptop):
root@cafe:~> uname -a
Linux cafe 4.4.27-2-default #1 SMP Thu Nov 3 14:59:54 UTC 2016 (5c21e7c) x86_64
x86_64 x86_64 GNU/Linux
root@cafe:~> lsmod | egrep btusb
btusb 49152 0
btrtl 16384 1 btusb
btbcm 16384 2 btusb,hci_uart
btintel 16384 2 btusb,hci_uart
bluetooth 532480 50
bnep,hidp,btbcm,btqca,btrtl,btusb,hci_uart,rfcomm,btintel
usbcore 270336 7
btusb,r8152,uvcvideo,usbnet,xhci_hcd,xhci_pci,cdc_ether
root@cafe:~> bluetoothctl
[NEW] Controller E4:A7:A0:E6:C8:81 cafe [default]
[NEW] Device C0:33:5E:05:7F:B8 Microsoft Sculpt Comfort Mouse
[NEW] Device 20:73:00:20:D3:29 Anker A7721
Dec 07 09:21:29 cafe PackageKit[3008]: refresh-cache transaction /1_bebadeac
from uid 1000 finished with success after 16084ms
Dec 07 09:21:30 cafe PackageKit[3008]: get-updates transaction /2_daaedace from
uid 1000 finished with success after 815ms
Dec 07 09:21:47 cafe kernel: apple 0005:05AC:022C.0003: unknown main item tag
0x0
Dec 07 09:21:47 cafe kernel: input: Anker A7721 as
/devices/pci0000:00/0000:00:14.0/usb1/1-4/1-4:1.0/bluetooth/hci0/hci0:512/0005:05AC:022C.0003/input/input19
Dec 07 09:21:47 cafe kernel: apple 0005:05AC:022C.0003: input,hidraw2:
BLUETOOTH HID v0.01 Keyboard [Anker A7721] on e4:a7:a0:e6:c8:81
Dec 07 09:21:47 cafe kernel: ------------[ cut here ]------------
Dec 07 09:21:47 cafe kernel: WARNING: CPU: 4 PID: 3464 at
../kernel/sched/core.c:7913 __might_sleep+0x76/0x80()
Dec 07 09:21:47 cafe kernel: do not call blocking ops when !TASK_RUNNING;
state=1 set at [<ffffffffa0f99fd5>] hidp_session_thread+0x135/0x860 [hidp]
Dec 07 09:21:47 cafe kernel: Modules linked in: hid_apple hid_generic hidp cmac
ecb rfcomm vmnet(O) ppdev parport_pc parport nf_log_ipv6 xt_pkttype nf_log_ipv4
nf_log_common xt_LOG xt_limit fuse vmw_vso
ck_vmci_transport vsock vmw_vmci vmmon(O) af_packet ip6t_REJECT nf_reject_ipv6
xt_tcpudp nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_raw ipt_REJECT
nf_reject_ipv4 iptable_raw xt_CT iptable_filter ip6table
_mangle nf_conntrack_netbios_ns nf_conntrack_broadcast nf_conntrack_ipv4
nf_defrag_ipv4 ip_tables xt_conntrack nf_conntrack ip6table_filter ip6_tables
x_tables bnep hid_multitouch arc4 xfs libcrc32c snd
_hda_codec_hdmi dell_led snd_hda_codec_realtek snd_hda_codec_generic intel_rapl
x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel snd_hda_intel kvm
irqbypass snd_hda_codec dell_rbtn snd_hda_core
crct10dif_pclmul
Dec 07 09:21:47 cafe kernel: uvcvideo iwlmvm crc32_pclmul snd_hwdep
crc32c_intel videobuf2_vmalloc dell_laptop videobuf2_memops snd_pcm dell_wmi
videobuf2_v4l2 cdc_ether iTCO_wdt videobuf2_core dcdbas
iTCO_vendor_support v4l2_common usbnet i2c_designware_platform
i2c_designware_core sparse_keymap snd_timer dell_smm_hwmon mac80211 drbg r8152
ansi_cprng snd videodev mii aesni_intel aes_x86_64 lrw hci_u
art gf128mul glue_helper ablk_helper btusb iwlwifi cryptd soundcore btrtl btqca
pcspkr btbcm joydev idma64 i2c_i801 rtsx_pci_ms btintel cfg80211 virt_dma
bluetooth memstick rfkill mei_me int3403_thermal
intel_lpss_pci mei dell_smo8800 pinctrl_sunrisepoint int3400_thermal
pinctrl_intel acpi_thermal_rel processor_thermal_device intel_soc_dts_iosf
int3402_thermal int340x_thermal_zone fan intel_lpss_acpi
intel_lpss acpi_als
Dec 07 09:21:47 cafe kernel: shpchp acpi_pad ac kfifo_buf battery industrialio
thermal processor fjes ext4 crc16 jbd2 mbcache sd_mod rtsx_pci_sdmmc mmc_core
sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_
emc scsi_dh_alua serio_raw nouveau mxm_wmi i915 ttm xhci_pci ahci xhci_hcd
libahci i2c_algo_bit libata rtsx_pci mfd_core usbcore drm_kms_helper
syscopyarea usb_common sysfillrect scsi_mod sysimgblt fb_s
ys_fops drm i2c_hid wmi video button bbswitch(O) autofs4
Dec 07 09:21:47 cafe kernel: CPU: 4 PID: 3464 Comm: khidpd_05ac022c Tainted: G
O 4.4.27-2-default #1
Dec 07 09:21:47 cafe kernel: Hardware name: Dell Inc. Precision 5510/0N8J4R,
BIOS 1.2.14 08/31/2016
Dec 07 09:21:47 cafe kernel: 0000000000000000 ffffffff81327657
ffff88082377fc70 ffffffff81a5e889
Dec 07 09:21:47 cafe kernel: ffffffff8107e821 ffffffff81ac3bc3
ffff88082377fcc0 0000000000000987
Dec 07 09:21:47 cafe kernel: 0000000000000000 0000000000000000
ffffffff8107e89c ffffffff81a4f308
Dec 07 09:21:47 cafe kernel: Call Trace:
Dec 07 09:21:47 cafe kernel: [<ffffffff81019e69>] dump_trace+0x59/0x320
Dec 07 09:21:47 cafe kernel: [<ffffffff8101a22a>]
show_stack_log_lvl+0xfa/0x180
Dec 07 09:21:47 cafe kernel: [<ffffffff8101afd1>] show_stack+0x21/0x40
Dec 07 09:21:47 cafe kernel: [<ffffffff81327657>] dump_stack+0x5c/0x85
Dec 07 09:21:47 cafe kernel: [<ffffffff8107e821>]
warn_slowpath_common+0x81/0xb0
Dec 07 09:21:47 cafe kernel: [<ffffffff8107e89c>] warn_slowpath_fmt+0x4c/0x50
Dec 07 09:21:47 cafe kernel: [<ffffffff810a3106>] __might_sleep+0x76/0x80
Dec 07 09:21:47 cafe kernel: [<ffffffff814fb694>] lock_sock_nested+0x24/0x70
Dec 07 09:21:47 cafe kernel: [<ffffffffa08e3a13>] l2cap_sock_sendmsg+0x53/0xf0
[bluetooth]
Dec 07 09:21:47 cafe kernel: [<ffffffff814f6fb0>] sock_sendmsg+0x30/0x40
Dec 07 09:21:47 cafe kernel: [<ffffffffa0f991ef>] hidp_send_frame+0x4f/0x80
[hidp]
Dec 07 09:21:47 cafe kernel: [<ffffffffa0f99254>]
hidp_process_transmit+0x34/0xb0 [hidp]
Dec 07 09:21:47 cafe kernel: [<ffffffffa0f9a1e6>]
hidp_session_thread+0x346/0x860 [hidp]
Dec 07 09:21:47 cafe kernel: [<ffffffff8109d328>] kthread+0xc8/0xe0
Dec 07 09:21:47 cafe kernel: [<ffffffff8160978f>] ret_from_fork+0x3f/0x70
Dec 07 09:21:47 cafe kernel: DWARF2 unwinder stuck at ret_from_fork+0x3f/0x70
Dec 07 09:21:47 cafe kernel:
Dec 07 09:21:47 cafe kernel: Leftover inexact backtrace:
Dec 07 09:21:47 cafe kernel: [<ffffffff8109d260>] ? kthread_park+0x50/0x50
Dec 07 09:21:47 cafe kernel: ---[ end trace fc815241443b8872 ]---