kernel-packages team mailing list archive

[Gabriele <1245328@xxxxxxxxxxxxxxxxxx>]

The kernel is not reporting to the userspace the width of the fingers
with new touchpads, even if the hardware is capable of that. The reason
is that pressure and width are not independent, so knowing one of them
is enough (at least according to what's written here:
https://lkml.org/lkml/2011/8/15/73).

The problem here is that the userspace driver was not updated to meet
this decision and hence the patch I posted here above is required.

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https://bugs.launchpad.net/bugs/1245328

Title:
  Synaptics kernel driver does not report finger width information,
  breaking usermode driver's palm detection

Status in “linux” package in Ubuntu:
  Confirmed

Bug description:
  While doing some work on the Xorg synaptics driver, I noticed that we
  never actually detect palm blocking even after running synclient
  PalmDetect=1. Digging in a bit, the driver claims in its capability
  bits that it should be sending ABS_TOOL_WIDTH records, but according
  to evtest(1), the driver never sends these advertised records to
  userspace. As a result, the Xorg synaptics driver never sees
  hw->fingerWidth become non-zero in SynapticsDetectFinger and never
  detects that I've mashed my palm into the large touchpad on this
  machine.

  Expected:

  Kill X. Run evtest(1). Select touchpad device. Move touchpad. See
  ABS_TOOL_WIDTH records in the event stream.

  Actual:

  No ABS_TOOL_WIDTH records even though the device claims to support
  them in its capability bits.

  ProblemType: Bug
  DistroRelease: Ubuntu 13.10
  Package: linux-image-3.11.0-12-generic 3.11.0-12.19 [modified: boot/vmlinuz-3.11.0-12-generic]
  ProcVersionSignature: Ubuntu 3.11.0-12.19-generic 3.11.3
  Uname: Linux 3.11.0-12-generic x86_64
  ApportVersion: 2.12.5-0ubuntu2.1
  Architecture: amd64
  AudioDevicesInUse:
   USER        PID ACCESS COMMAND
   /dev/snd/controlC0:  dancol     2258 F.... pulseaudio
  Date: Sun Oct 27 21:43:01 2013
  HibernationDevice: RESUME=UUID=7da7377a-42c7-49f8-a060-8dee466c61fd
  InstallationDate: Installed on 2013-10-23 (4 days ago)
  InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
  MachineType: LENOVO 34601F5
  MarkForUpload: True
  ProcFB: 0 inteldrmfb
  ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.11.0-12-generic root=/dev/mapper/ubuntu--vg-root ro quiet splash vt.handoff=7
  RelatedPackageVersions:
   linux-restricted-modules-3.11.0-12-generic N/A
   linux-backports-modules-3.11.0-12-generic  N/A
   linux-firmware                             1.116
  SourcePackage: linux
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 04/29/2013
  dmi.bios.vendor: LENOVO
  dmi.bios.version: G6ET96WW (2.56 )
  dmi.board.asset.tag: Not Available
  dmi.board.name: 34601F5
  dmi.board.vendor: LENOVO
  dmi.board.version: Not Defined
  dmi.chassis.asset.tag: 2059198
  dmi.chassis.type: 10
  dmi.chassis.vendor: LENOVO
  dmi.chassis.version: Not Available
  dmi.modalias: dmi:bvnLENOVO:bvrG6ET96WW(2.56):bd04/29/2013:svnLENOVO:pn34601F5:pvrThinkPadX1Carbon:rvnLENOVO:rn34601F5:rvrNotDefined:cvnLENOVO:ct10:cvrNotAvailable:
  dmi.product.name: 34601F5
  dmi.product.version: ThinkPad X1 Carbon
  dmi.sys.vendor: LENOVO

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