The problem just happened to me again. I am including bellow the dmesg information. [39935.550219] ACPI: Waking up from system sleep state S3 [39936.749233] ehci-pci 0000:00:1d.0: System wakeup disabled by ACPI [39936.749486] xhci_hcd 0000:00:14.0: System wakeup disabled by ACPI [39936.749535] PM: noirq resume of devices complete after 16.818 msecs [39936.772659] PM: early resume of devices complete after 23.055 msecs [39936.772771] usb usb1: root hub lost power or was reset [39936.772772] usb usb2: root hub lost power or was reset [39936.773878] sd 3:0:0:0: [sda] Starting disk [39936.774743] rtc_cmos 00:01: System wakeup disabled by ACPI [39936.957171] cfg80211: Calling CRDA to update world regulatory domain [39937.000773] usb 3-1: reset high-speed USB device number 2 using ehci-pci [39937.096852] ata4: SATA link up 6.0 Gbps (SStatus 133 SControl 300) [39937.098948] ata4.00: failed to get NCQ Send/Recv Log Emask 0x1 [39937.099202] ata4.00: failed to get NCQ Send/Recv Log Emask 0x1 [39937.099240] ata4.00: configured for UDMA/133 [39937.277116] usb 1-3: reset full-speed USB device number 2 using xhci_hcd [39937.406403] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff8802149b9e00 [39937.406404] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff8802149b9e90 [39937.406405] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff8802149b9e48 [39937.406412] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff880212979948 [39937.406413] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff880212979900 [39937.406413] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff880212979288 [39937.406414] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff880212979240 [39937.517280] usb 1-4: reset full-speed USB device number 3 using xhci_hcd [39937.645962] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff8800d90cd3c0 [39937.645963] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff8800d90cd408 [39937.645976] usb 1-4: ep 0x2 - rounding interval to 64 microframes, ep desc says 80 microframes [39937.757453] usb 1-5: reset high-speed USB device number 4 using xhci_hcd [39937.995391] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff8800d8fb2f60 [39937.995398] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff8800d8fb2f00 [39938.038325] PM: resume of devices complete after 1264.639 msecs [39938.038849] ------------[ cut here ]------------ [39938.038853] WARNING: CPU: 1 PID: 8500 at /build/buildd/linux-3.19.0/drivers/base/firmware_class.c:1126 _request_firmware+0x72e/0xbd0() [39938.038877] Modules linked in: cpuid mmc_block ses enclosure uas usb_storage hid_generic hidp binfmt_misc rfcomm bnep nls_iso8859_1 uvcvideo videobuf2_vmalloc videobuf2_memops btusb videobuf2_core bluetooth v4l2_common videodev usbhid media dell_led joydev dell_wmi hid_multitouch sparse_keymap dell_laptop dcdbas intel_rapl iosf_mbi x86_pkg_temp_thermal snd_hda_codec_realtek i915_bpo intel_powerclamp coretemp wl(POE) snd_hda_codec_generic intel_ips kvm_intel kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd cfg80211 snd_hda_intel rtsx_pci_ms snd_hda_controller serio_raw snd_hda_codec memstick lpc_ich snd_hwdep snd_seq_midi snd_soc_rt286 snd_seq_midi_event snd_soc_core snd_rawmidi snd_compress snd_pcm_dmaengine i915 snd_pcm snd_seq [39938.038890] i2c_hid snd_seq_device hid drm_kms_helper drm snd_timer mei_me snd mei shpchp soundcore i2c_algo_bit wmi soc_button_array snd_soc_sst_acpi i2c_designware_platform int3403_thermal i2c_designware_core dw_dmac video 8250_dw dw_dmac_core int3400_thermal int3402_thermal acpi_thermal_rel spi_pxa2xx_platform processor_thermal_device acpi_pad mac_hid parport_pc ppdev lp parport autofs4 rtsx_pci_sdmmc ahci psmouse libahci rtsx_pci sdhci_acpi sdhci [39938.038892] CPU: 1 PID: 8500 Comm: kworker/u9:0 Tainted: P W OE 3.19.0-18-generic #18-Ubuntu [39938.038892] Hardware name: Dell Inc. XPS 13 9343/0310JH, BIOS A03 03/25/2015 [39938.038900] Workqueue: hci0 hci_power_on [bluetooth] [39938.038902] ffffffff81b10ca0 ffff8800da35bb78 ffffffff817c27cd ffffffff81c54db8 [39938.038903] 0000000000000000 ffff8800da35bbb8 ffffffff8107593a ffffffff815196ca [39938.038904] ffff8800da35bcd0 ffff8800bbc185a0 ffff8801c299b780 00000000fffffff5 [39938.038904] Call Trace: [39938.038907] [] dump_stack+0x45/0x57 [39938.038909] [] warn_slowpath_common+0x8a/0xc0 [39938.038910] [] ? _request_firmware+0x5a/0xbd0 [39938.038911] [] warn_slowpath_null+0x1a/0x20 [39938.038912] [] _request_firmware+0x72e/0xbd0 [39938.038913] [] request_firmware+0x35/0x50 [39938.038916] [] btusb_setup_bcm_patchram+0x89/0x570 [btusb] [39938.038917] [] ? rpm_idle+0xd6/0x230 [39938.038922] [] hci_dev_do_open+0xe1/0xa90 [bluetooth] [39938.038927] [] hci_power_on+0x40/0x200 [bluetooth] [39938.038929] [] process_one_work+0x158/0x430 [39938.038930] [] worker_thread+0x5b/0x530 [39938.038931] [] ? rescuer_thread+0x3a0/0x3a0 [39938.038932] [] kthread+0xc9/0xe0 [39938.038934] [] ? kthread_create_on_node+0x1c0/0x1c0 [39938.038936] [] ret_from_fork+0x58/0x90 [39938.038937] [] ? kthread_create_on_node+0x1c0/0x1c0 [39938.038938] ---[ end trace 65c9a7c064322ff2 ]--- [39938.038940] bluetooth hci0: firmware: brcm/BCM20702A0-0a5c-216f.hcd will not be loaded [39938.038941] Bluetooth: hci0: BCM: patch brcm/BCM20702A0-0a5c-216f.hcd not found [39938.039014] PM: Finishing wakeup. [39938.039015] Restarting tasks ... [39938.039569] pci_bus 0000:01: Allocating resources [39938.039682] pci_bus 0000:02: Allocating resources [39938.039725] i915 0000:00:02.0: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment [39938.039913] pci_bus 0000:01: Allocating resources [39938.040023] pci_bus 0000:02: Allocating resources [39938.040065] i915 0000:00:02.0: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment [39938.040139] i915 0000:00:02.0: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment [39938.040244] i915 0000:00:02.0: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment [39938.040341] i915 0000:00:02.0: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment [39938.040671] pci_bus 0000:01: Allocating resources [39938.040791] pci_bus 0000:02: Allocating resources [39938.040833] i915 0000:00:02.0: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment [39938.041469] i915 0000:00:02.0: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment [39938.041548] i915 0000:00:02.0: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment [39938.041650] i915 0000:00:02.0: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment [39938.041669] i915 0000:00:02.0: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment [39938.041688] i915 0000:00:02.0: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment [39938.045090] done. [39938.046734] cfg80211: World regulatory domain updated: [39938.046737] cfg80211: DFS Master region: unset [39938.046739] cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time) [39938.046742] cfg80211: (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A) [39938.046744] cfg80211: (2457000 KHz - 2482000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A) [39938.046746] cfg80211: (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm), (N/A) [39938.046748] cfg80211: (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A) [39938.046750] cfg80211: (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A) [39938.109603] systemd[1]: Unit suspend.target is bound to inactive unit systemd-suspend.service. Stopping, too. [39953.501153] hid-generic 0005:046D:B00E.0006: unknown main item tag 0x0 [39953.763130] input: Dell Travel Mouse WM524 as /devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3:1.0/bluetooth/hci0/hci0:12/0005:046D:B00E.0006/input/input24 [39953.763453] hid-generic 0005:046D:B00E.0006: input,hidraw2: BLUETOOTH HID v8.00 Mouse [Dell Travel Mouse WM524] on ac:d1:b8:c0:6f:5c cribari@darwin4:~$