Why does ABRT throw a kernel WARNING: at drivers/usb/host/ehci-hcd.c:1027 ehci_endpoint_reset+0x101/0x110()?

Issue

• [abrt] kernel: WARNING: at drivers/usb/host/ehci-hcd.c:1027 ehci_endpoint_reset+0x101/0x110()

abrt_version:   2.1.11
cmdline:        BOOT_IMAGE=/vmlinuz-3.10.0-123.el7.x86_64 root=UUID=4a6c0204-a308-48cb-abc4-b14cdb4c2b1b ro rd.lvm.lv=rhel/root crashkernel=auto rd.lvm.lv=rhel/swap vconsole.font=latarcyrheb-sun16 vconsole.keymap=us rhgb quiet LANG=en_US.UTF-8
comment:        just clicked umount in the Kde diskmount icon. 
kernel:         3.10.0-123.el7.x86_64
last_occurrence: 1407140285
pkg_arch:       x86_64
pkg_epoch:      0
pkg_name:       kernel
pkg_release:    123.el7
pkg_version:    3.10.0
runlevel:       N 5
time:           Thu 31 Jul 2014 04:04:05 PM EST

dmesg:          Text file, 75713 bytes
proc_modules:   Text file, 7805 bytes
sosreport.tar.xz: Binary file, 5192788 bytes

backtrace:
:WARNING: at drivers/usb/host/ehci-hcd.c:1027 ehci_endpoint_reset+0x101/0x110()
:clear_halt for a busy endpoint
:Modules linked in: cdc_acm btrfs zlib_deflate raid6_pq xor vfat msdos fat ext4 mbcache jbd2 binfmt_misc lp parport usb_storage usblp nls_utf8 isofs tcp_lp bnep bluetooth fuse ip6t_rpfilter ip6t_REJECT ipt_REJECT xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw iptable_filter ip_tables sg coretemp kvm_intel kvm arc4 ath9k ath9k_common ath9k_hw ath mac80211 cfg80211 snd_hda_codec_hdmi crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec
:iTCO_wdt iTCO_vendor_support aesni_intel snd_hwdep snd_seq snd_seq_device snd_pcm snd_page_alloc snd_timer snd lrw soundcore mei_me mei gf128mul i2c_i801 ir_lirc_codec glue_helper ablk_helper cryptd rfkill serio_raw shpchp pcspkr lpc_ich mfd_core lirc_dev ir_sony_decoder ir_sanyo_decoder ir_rc6_decoder ir_rc5_decoder ir_nec_decoder ir_mce_kbd_decoder ir_jvc_decoder rc_rc6_mce nuvoton_cir rc_core mperf nfsd auth_rpcgss nfs_acl lockd sunrpc uinput xfs libcrc32c sd_mod sr_mod crc_t10dif cdrom crct10dif_common nouveau i915 mxm_wmi ttm ahci libahci i2c_algo_bit drm_kms_helper libata drm r8169 mii i2c_core video wmi dm_mirror dm_region_hash dm_log dm_mod
:CPU: 2 PID: 17087 Comm: pool Not tainted 3.10.0-123.el7.x86_64 #1
:Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./HM65-MXM, BIOS P1.10 09/16/2011
:ffff880067f65d18 00000000133209a9 ffff880067f65cd0 ffffffff815e19ba
:ffff880067f65d08 ffffffff8105dee1 0000000000000003 0000000000000083
:ffff880126228000 ffff88012622830c 0000000000000246 ffff880067f65d70
:Call Trace:
:[<ffffffff815e19ba>] dump_stack+0x19/0x1b
:[<ffffffff8105dee1>] warn_slowpath_common+0x61/0x80
:[<ffffffff8105df5c>] warn_slowpath_fmt+0x5c/0x80
:[<ffffffff81414de1>] ehci_endpoint_reset+0x101/0x110
:[<ffffffff813fa545>] usb_hcd_reset_endpoint+0x25/0x70
:[<ffffffff813fc798>] usb_reset_endpoint+0x28/0x40
:[<ffffffff813fc81e>] usb_clear_halt+0x6e/0x80
:[<ffffffff81407ad5>] usbdev_do_ioctl+0x965/0xf70
:[<ffffffff8140810e>] usbdev_ioctl+0xe/0x20
:[<ffffffff811c2f25>] do_vfs_ioctl+0x2e5/0x4c0
:[<ffffffff81257a2e>] ? file_has_perm+0xae/0xc0
:[<ffffffff811c31a1>] SyS_ioctl+0xa1/0xc0
:[<ffffffff815f2119>] system_call_fastpath+0x16/0x1b