kernel-packages team mailing list archive

[Roland Weber <r-o-l@xxxxxx>]

Current state of things: I've tracked down the code line where the
freeze happens. It's in function ehci_halt within file ehci-hcd.c. The
function is executed on shutdown as well as when the usb devices on the
bus are about to be probed again. The latter is triggered by "lsusb -v"
as root. Apparently, the hardware misbehaves by not responding to a
"readl" call.

As a workaround, it is possible to compile kernel 4.2 with a patch that
disables the unused EHCI USB bus. However, this is *not* a generic
solution! The same chip may be built into other computers, and the EHCI
bus may be used there.

** Patch added: "Patch to blacklist the problematic EHCI bus. This is a workaround, NOT a solution!"
   https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1485057/+attachment/4462350/+files/blacklist-evil-ehci-device.diff

-- 
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/1485057

Title:
  "lsusb -v" as root freezes the kernel on Acer ES1-111; also freeze on
  shutdown

Status in linux package in Ubuntu:
  Triaged

Bug description:
  reproducible: always

  Steps to reproduce:
  - open a terminal
  - sudo bash
  - lsusb -v

  In a virtual terminal, the command prints the name of the first device
  it finds, then the system freezes completely. In a terminal of the
  desktop, I don't even get the name of the device, the system freezes
  immediately. Either way, I have to power off the machine. There is no
  kernel oops. Nothing is written to the log. The magic sysreq key
  yields no response, although I have verified that it works before
  triggering the freeze.

  I've narrowed down the problem by calling "lsusb -v -s <device>". The
  system freezes on both devices of bus 3 (003:001 and 003:002). For all
  other devices, it prints the expected output and continues to work.
  When calling lsusb as a regular user, I get "Couldn't open device,
  some information will be missing", then the regular output, and the
  system keeps running. Therefore I assume that the problem is somewhere
  in the kernel, when the devices are accessed.

  This is a regression. It used to work in 14.10, and fails to work since 15.04.
  It also used to work in 14.04.2, and fails in 14.04.3.
  It fails with mainline builds 4.2.0-rc6-unstable, 4.2.0-rc2-unstable, 4.1.0-rc2-vivid. (yeah, I've been trying for a while :-)

  Incidentally, the shutdown sequence also freezes with the kernels that
  exhibit the problem; but I cannot be sure that the cause is the same.
  I decided to first chase the USB freeze, because it was easier to
  gather information about that.

  ProblemType: Bug
  DistroRelease: Ubuntu 15.04
  Package: linux-image-3.19.0-25-generic 3.19.0-25.26
  ProcVersionSignature: Ubuntu 3.19.0-25.26-generic 3.19.8-ckt2
  Uname: Linux 3.19.0-25-generic x86_64
  ApportVersion: 2.17.2-0ubuntu1.2
  Architecture: amd64
  AudioDevicesInUse:
   USER        PID ACCESS COMMAND
   /dev/snd/controlC0:  rweber     1525 F.... pulseaudio
  CurrentDesktop: XFCE
  Date: Fri Aug 14 18:38:36 2015
  HibernationDevice: RESUME=UUID=8a45266d-0232-428e-bb25-113d23caaf8a
  InstallationDate: Installed on 2015-06-28 (46 days ago)
  InstallationMedia: Xubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
  MachineType: Acer Aspire ES1-111M
  ProcFB: 0 inteldrmfb
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.19.0-25-generic root=UUID=b8872e03-7295-4cbd-ac86-06b9be2f112f ro quiet splash crashkernel=384M-:128M vt.handoff=7
  RelatedPackageVersions:
   linux-restricted-modules-3.19.0-25-generic N/A
   linux-backports-modules-3.19.0-25-generic  N/A
   linux-firmware                             1.143.3
  SourcePackage: linux
  UpgradeStatus: Upgraded to vivid on 2015-07-05 (39 days ago)
  dmi.bios.date: 08/20/2014
  dmi.bios.vendor: Insyde Corp.
  dmi.bios.version: V1.08
  dmi.board.asset.tag: Type2 - Board Asset Tag
  dmi.board.name: R2
  dmi.board.vendor: Acer
  dmi.board.version: Type2 - A01 Board Version
  dmi.chassis.type: 10
  dmi.chassis.vendor: Chassis Manufacturer
  dmi.chassis.version: Chassis Version
  dmi.modalias: dmi:bvnInsydeCorp.:bvrV1.08:bd08/20/2014:svnAcer:pnAspireES1-111M:pvrV1.08:rvnAcer:rnR2:rvrType2-A01BoardVersion:cvnChassisManufacturer:ct10:cvrChassisVersion:
  dmi.product.name: Aspire ES1-111M
  dmi.product.version: V1.08
  dmi.sys.vendor: Acer

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1485057/+subscriptions