The Precision Touchpad(PTP) button sends incorrect event code

[AceLan Kao]

[Impact]
The touchpad right button should send 273(BTN_RIGHT),
and the left button should send 272(BTN_LEFT)
But the touchpad right button sends 274(BTN_MIDDLE),
and the left button sends 273 (BTN_RIGHT)

[Fix]
The fix is pretty simple to just decrease the event code by 1.

[Test Case]
Verified on the machine has this issue, and confirm this patch works.

[Regression Potential]
The patch has strict if statement, so it won't affect other touchpad devices.
And no more rework on this code snip after this commit.

[AceLan Kao (acelankao)]

commit 504c932c7c47a6b4c572302a13873f7d83af1ff3
Author: Masaki Ota <email address hidden>
Date: Fri Jun 16 09:29:39 2017 +0900

    HID: multitouch: Support PTP Stick and Touchpad device

    Support PTP Stick and Touchpad device. This Touchpad is Precision Touchpad
    (PTP), and Stick Pointer data is the same as Mouse; Stick Pointer works as
    Mouse.

    [<email address hidden>: changelog deuglification]
    Signed-off-by: Masaki Ota <email address hidden>
    Reviewed-by: Benjamin Tissoires <email address hidden>
    Signed-off-by: Jiri Kosina <email address hidden>

[Kleber Sacilotto de Souza (kleber-souza)]

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-xenial' to 'verification-done-xenial'. If the problem still exists, change the tag 'verification-needed-xenial' to 'verification-failed-xenial'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.4.0-93.116

---------------
linux (4.4.0-93.116) xenial; urgency=low

  * linux: 4.4.0-93.116 -proposed tracker (LP: #1709296)

  * Creating conntrack entry failure with kernel 4.4.0-89 (LP: #1709032)
    - Revert "Revert "netfilter: synproxy: fix conntrackd interaction""
    - netfilter: nf_ct_ext: fix possible panic after nf_ct_extend_unregister

  * CVE-2017-1000112
    - Revert "udp: consistently apply ufo or fragmentation"
    - udp: consistently apply ufo or fragmentation

  * CVE-2017-1000111
    - Revert "net-packet: fix race in packet_set_ring on PACKET_RESERVE"
    - packet: fix tp_reserve race in packet_set_ring

  * kernel BUG at [tty_ldisc_reinit] mm/slub.c! (LP: #1709126)
    - tty: Simplify tty_set_ldisc() exit handling
    - tty: Reset c_line from driver's init_termios
    - tty: Handle NULL tty->ldisc
    - tty: Move tty_ldisc_kill()
    - tty: Use 'disc' for line discipline index name
    - tty: Refactor tty_ldisc_reinit() for reuse
    - tty: Destroy ldisc instance on hangup

  * atheros bt failed after S3 (LP: #1706833)
    - SAUCE: Bluetooth: Make request workqueue freezable

  * The Precision Touchpad(PTP) button sends incorrect event code (LP: #1708372)
    - HID: multitouch: handle external buttons for Precision Touchpads

  * Set CONFIG_SATA_HIGHBANK=y on armhf (LP: #1703430)
    - [Config] CONFIG_SATA_HIGHBANK=y

  * xfs slab objects (memory) leak when xfs shutdown is called (LP: #1706132)
    - xfs: fix xfs_log_ticket leak in xfs_end_io() after fs shutdown

  * Adt tests of src:linux time out often on armhf lxc containers (LP: #1705495)
    - [Packaging] tests -- reduce rebuild test to one flavour

  * CVE-2017-7495
    - ext4: fix data exposure after a crash

  * ubuntu/rsi driver downlink wifi throughput drops to 5-6 Mbps when BT
    keyboard is connected (LP: #1706991)
    - SAUCE: Redpine: enable power save by default for coex mode
    - SAUCE: Redpine: uapsd configuration changes

  * [Hyper-V] hv_netvsc: Exclude non-TCP port numbers from vRSS hashing
    (LP: #1690174)
    - hv_netvsc: Exclude non-TCP port numbers from vRSS hashing

  * ath10k doesn't report full RSSI information (LP: #1706531)
    - ath10k: add per chain RSSI reporting

  * ideapad_laptop don't support v310-14isk (LP: #1705378)
    - platform/x86: ideapad-laptop: Add several models to no_hw_rfkill

  * [8087:0a2b] Failed to load bluetooth firmware(might affect some other Intel
    bt devices) (LP: #1705633)
    - Bluetooth: btintel: Create common Intel Version Read function
    - Bluetooth: Use switch statement for Intel hardware variants
    - Bluetooth: Replace constant hw_variant from Intel Bluetooth firmware
      filename
    - Bluetooth: hci_intel: Fix firmware file name to use hw_variant
    - Bluetooth: btintel: Add MODULE_FIRMWARE entries for iBT 3.5 controllers

  * xhci_hcd: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2
    comp_code 13 (LP: #1667750)
    - xhci: Bad Ethernet performance plugged in ASM1042A host

  * OpenPower: Some multipaths temporarily have only a single path
    (LP: #1696445)
    - scsi: ses: don't get power status of SES device slot on probe

  ...