Several NFC readers do not work properly due to pcsclite bug (in libusb hotplug). Bugs were fixed in version 1.8.13, but Trusty uses old 1.8.10 version.
http://anonscm.debian.org/viewvc/pcsclite/trunk/PCSC/ChangeLog?view=co
pcscd logs:
1. Reader ACS122U:
42850162 hotplug_libudev.c:269:get_driver() Looking for a driver for VID: 0x072F, PID: 0x2200, path: /dev/bus/usb/001/019
00000012 hotplug_libudev.c:321:HPAddDevice() Adding USB device: ACS ACR122U
00000026 readerfactory.c:989:RFInitializeReader() Attempting startup of ACS ACR122U 00 00 using /usr/lib/pcsc/drivers/ifd-acsccid.bundle/Contents/Linux/libacsccid.so
00000104 readerfactory.c:874:RFBindFunctions() Loading IFD Handler 3.0
00000020 ifdhandler.c:2577:init_driver() Driver version: 1.1.0
00000176 ifdhandler.c:2594:init_driver() LogLevel: 0x0003
00000005 ifdhandler.c:2605:init_driver() DriverOptions: 0x0000
00000004 ifdhandler.c:2613:init_driver() ACSDriverOptions: 0x0003
00000004 ifdhandler.c:2621:init_driver() ACR38CardVoltage: 0
00000004 ifdhandler.c:2629:init_driver() ACR38CardType: 0
00000029 ifdhandler.c:104:CreateChannelByNameOrChannel() Lun: 0, device: usb:072f/2200:libudev:0:/dev/bus/usb/001/019
00000013 ccid_usb.c:307:OpenUSBByName() Using: /usr/lib/pcsc/drivers/ifd-acsccid.bundle/Contents/Info.plist
00000159 ccid_usb.c:325:OpenUSBByName() ifdManufacturerString: Advanced Card Systems Ltd.
00000004 ccid_usb.c:326:OpenUSBByName() ifdProductString: ACS CCID driver
00000003 ccid_usb.c:327:OpenUSBByName() Copyright: This driver is protected by terms of the GNU Lesser General Public License version 2.1, or (at your option) any later version.
00003508 ccid_usb.c:680:OpenUSBByName() Can't claim interface 1/19: -6
00000017 ccid_usb.c:214:close_libusb_if_needed() libusb_exit
00004646 ifdhandler.c:140:CreateChannelByNameOrChannel() failed
00000015 readerfactory.c:1020:RFInitializeReader() Open Port 0x200000 Failed (usb:072f/2200:libudev:0:/dev/bus/usb/001/019)
00000008 readerfactory.c:312:RFAddReader() ACS ACR122U init failed.
00000009 readerfactory.c:535:RFRemoveReader() UnrefReader() count was: 1
00000009 readerfactory.c:1040:RFUnInitializeReader() Attempting shutdown of ACS ACR122U 00 00.
00000008 readerfactory.c:911:RFUnloadReader() Unloading reader driver.
00000070 hotplug_libudev.c:391:HPAddDevice() Failed adding USB device: ACS ACR122U
2. Reader SCL3711:
04276562 hotplug_libudev.c:269:get_driver() Looking for a driver for VID: 0x04E6, PID: 0x5591, path: /dev/bus/usb/001/018
00000011 hotplug_libudev.c:321:HPAddDevice() Adding USB device: SCL3711 Reader and NFC Device
00000027 readerfactory.c:989:RFInitializeReader() Attempting startup of SCL3711 Reader and NFC Device 00 00 using /usr/lib/pcsc/drivers/SCx371x.bundle/Contents/Linux/libSCx371x.so.2.18
00000124 readerfactory.c:874:RFBindFunctions() Loading IFD Handler 3.0
Loading lib v2.18
00049066 readerfactory.c:1020:RFInitializeReader() Open Port 0x200000 Failed (usb:04e6/5591:libudev:0:/dev/bus/usb/001/018)
00000012 readerfactory.c:312:RFAddReader() SCL3711 Reader and NFC Device init failed.
00000004 readerfactory.c:535:RFRemoveReader() UnrefReader() count was: 1
00000004 readerfactory.c:1040:RFUnInitializeReader() Attempting shutdown of SCL3711 Reader and NFC Device 00 00.
00000003 readerfactory.c:911:RFUnloadReader() Unloading reader driver.
00000034 hotplug_libudev.c:391:HPAddDevice() Failed adding USB device: SCL3711 Reader and NFC Device
ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: libpcsclite1 1.8.10-1ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-43.72-generic 3.13.11.11
Uname: Linux 3.13.0-43-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.6
Architecture: amd64
Date: Tue Dec 30 13:38:53 2014
Dependencies:
gcc-4.9-base 4.9.1-0ubuntu1
libc6 2.19-0ubuntu6.4
libgcc1 1:4.9.1-0ubuntu1
multiarch-support 2.19-0ubuntu6.4
InstallationDate: Installed on 2014-10-14 (76 days ago)
InstallationMedia: Ubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.2)
ProcEnviron:
TERM=xterm
PATH=(custom, no user)
XDG_RUNTIME_DIR=<set>
LANG=pl_PL.UTF-8
SHELL=/bin/bash
SourcePackage: pcsc-lite
UpgradeStatus: No upgrade log present (probably fresh install)
Why do you think it is a libusb hotplug bug?
What bugs _exactly_ are you referring too?