Tried 4.0-rc4 on vivid and saw none of the xhci error messages I saw on 3.19. I performed exactly the same operation using the same hardware, namely ddrescuing an ~7.5GB image to an 8GB stick.
alan@deep-thought:/data/usb⟫ dmesg -T | grep xhci_hcd [Mon Mar 16 19:48:40 2015] xhci_hcd 0000:0e:00.0: xHCI Host Controller [Mon Mar 16 19:48:40 2015] xhci_hcd 0000:0e:00.0: new USB bus registered, assigned bus number 1 [Mon Mar 16 19:48:40 2015] xhci_hcd 0000:0e:00.0: hcc params 0x014042cb hci version 0x96 quirks 0x00000004 [Mon Mar 16 19:48:40 2015] xhci_hcd 0000:0e:00.0: xHCI Host Controller [Mon Mar 16 19:48:40 2015] xhci_hcd 0000:0e:00.0: new USB bus registered, assigned bus number 2 [Mon Mar 16 19:49:49 2015] usb 2-1: new SuperSpeed USB device number 2 using xhci_hcd [Mon Mar 16 19:49:50 2015] usb 1-1: new high-speed USB device number 2 using xhci_hcd [Mon Mar 16 19:49:59 2015] usb 2-1.3: new SuperSpeed USB device number 3 using xhci_hcd [Mon Mar 16 19:54:59 2015] usb 2-1.3: new SuperSpeed USB device number 4 using xhci_hcd -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1371233 Title: USB 3.0 connection is unreliable + xHCI xhci_drop_endpoint called with disabled ep Status in linux package in Ubuntu: Confirmed Status in linux source package in Trusty: Confirmed Status in linux source package in Utopic: Confirmed Status in linux source package in Vivid: Confirmed Bug description: based on https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1358871/comments/7 I tested with the HDD enclosure IcyBox IB-351 series with USB 3.0 connection with the same result (connection drops after 300 MB reading, error message "xHCI xhci_drop_endpoint called with disabled ep" occurs sometimes, other devices (e.g. Samsung HD103SI 1 TB HDD connected with 3.0 USB adapter to eSATA of enclosure) read hundreds of GB before failing, but definitely do before reading 1TB). Reading tested with `dd`, `gpart` and `btrfsck`. Also confirmed on Lenovo IdeaPad-Z500 after BIOS update to 71CN51WW(V1.21) (changelog didn't indicate any USB issues anyway). Also confirmed with 3.16.3 and 3.16.0-14 on Ubuntu 14.10-beta1 after updates. The issue seems to cause failure of ASIX AX179 gigabit ethernet chip as well, but is independent from the usage of the ethernet adapter. I'm without any clue and stuck with an unreliable USB and ethernet connection which basically means no I/O out of the machine!! ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-image-3.13.0-35-generic 3.13.0-35.62 ProcVersionSignature: Ubuntu 3.13.0-35.62-generic 3.13.11.6 Uname: Linux 3.13.0-35-generic x86_64 ApportVersion: 2.14.1-0ubuntu3.4 Architecture: amd64 AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/by-path', '/dev/snd/controlC0', '/dev/snd/hwC0D0', '/dev/snd/hwC0D3', '/dev/snd/pcmC0D0c', '/dev/snd/pcmC0D0p', '/dev/snd/pcmC0D3p', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: CurrentDesktop: Unity Date: Thu Sep 18 19:58:24 2014 EcryptfsInUse: Yes InstallationDate: Installed on 2014-09-10 (8 days ago) InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417) MachineType: LENOVO 20221 ProcEnviron: TERM=xterm PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=de_DE.UTF-8 SHELL=/bin/bash ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/@/boot/vmlinuz-3.13.0-35-generic.efi.signed root=UUID=5e999111-7efe-4818-b9e8-a950ad6d3296 ro rootflags=subvol=@ quiet splash nomdmonddf nomdmonisw vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-3.13.0-35-generic N/A linux-backports-modules-3.13.0-35-generic N/A linux-firmware 1.127.5 SourcePackage: linux StagingDrivers: rts5139 UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 07/12/2013 dmi.bios.vendor: LENOVO dmi.bios.version: 71CN51WW(V1.21) dmi.board.asset.tag: No Asset Tag dmi.board.name: INVALID dmi.board.vendor: LENOVO dmi.board.version: 31900003WIN8 STD MLT dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Lenovo IdeaPad Z500 Touch dmi.modalias: dmi:bvnLENOVO:bvr71CN51WW(V1.21):bd07/12/2013:svnLENOVO:pn20221:pvrLenovoIdeaPadZ500Touch:rvnLENOVO:rnINVALID:rvr31900003WIN8STDMLT:cvnLENOVO:ct10:cvrLenovoIdeaPadZ500Touch: dmi.product.name: 20221 dmi.product.version: Lenovo IdeaPad Z500 Touch dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1371233/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp